What is the most important thing to do before rainy season starts in Costa Rica?

Roof inspection and gutter clearing, dehumidifier deployment, and pest perimeter treatment — in that order of urgency. The roof inspection should happen in March or April, before the first May rains. Have a local roofing contractor walk the entire roof surface and check: cracked or missing tiles (tile roofs), rust and screw holes (metal sheet roofs), deteriorated caulking around skylights and roof penetrations, and the state of the gutters and downspouts. Clear all gutters of the leaf and debris accumulation from dry season. Install dehumidifiers in bedrooms, the living area, and any room with wood furniture or fabric. Set them to 50–55% relative humidity and empty the collection basins daily (or connect to a drain hose). Have a pest professional treat the perimeter of the property in April — this creates a chemical barrier before the rainy season insect migration begins. These three steps, totaling $400–$700 USD, prevent problems that cost many times more to remediate.

How do I prevent mold in a Costa Rica property that sits empty during rainy season?

Running dehumidifiers is the single most important intervention. The secondary steps amplify their effectiveness: ensure the property is well-sealed (check weatherstripping on doors and windows before you leave), leave interior doors open to allow airflow between rooms, leave closet doors slightly ajar (mold loves the still air inside a closed closet), remove all food items and organic materials that can grow mold, treat mattresses and upholstered furniture with an anti-mold spray before closing, and instruct your property manager to ventilate the property for 30–60 minutes on sunny days — opening doors and windows to flush accumulated humidity. If you have ceiling fans, leave them running on low continuously — airflow dramatically slows mold growth. Dehumidifiers running continuously in occupied rooms plus fans running in unoccupied ones cover most scenarios. If you return and notice a musty smell, act immediately — surface mold is treatable; deep structural mold in drywall, wood framing, or inside mattresses often requires replacement.

What pests are the biggest problem in Costa Rica during rainy season?

Termites are the top structural concern year-round in Costa Rica but activity increases during rainy season when they swarm. A professional perimeter treatment before rainy season suppresses termite activity, but a full termite inspection of any older wooden structure should be annual. Ants (including leaf-cutter ants and biting fire ants) increase dramatically at rainy season start as flooded ground forces them to higher ground — including inside your property. Cockroaches follow the same pattern. In beach properties, sand fleas (no-see-ums) can be severe on Caribbean coast properties during certain wind conditions. Scorpions are present in many dry and transitional forest zones in Costa Rica — Guanacaste properties particularly — and hiding in shoes and damp areas during rainy season. Snakes increase in visibility during rainy season as they move to higher ground; this affects garden maintenance and requires alertness when clearing vegetation. These are manageable with awareness and treatment, not reasons to avoid Costa Rica, but new owners from Canada consistently underestimate the insect pressure.

What special maintenance does a pool need during Costa Rica's dry and rainy seasons?

Dry season (December–April) in Costa Rica brings intense sun and lower humidity. Evaporation increases, chlorine burns off faster due to UV intensity, and algae growth is slower but dust and debris accumulate more. During dry season, increase chlorine dosing frequency, monitor water level and top up more often, clean the pool filter more frequently due to dust accumulation, and clean the tile line regularly as mineral deposits concentrate faster. During rainy season, rainfall dilutes the pool chemistry constantly. Every heavy rainstorm effectively performs a partial water change, requiring re-balancing of pH and alkalinity. Heavy organic debris (leaves, insects, frogs) increase the chlorine demand significantly. A pool service every 1–2 weeks during rainy season is standard; monthly during dry season may be sufficient for a clean-running pool. If your property sits unoccupied through peak rainy season (September–November), arrange for a pool service to visit and treat at least every two weeks or the pool will turn green, requiring an expensive shock treatment and filter cleaning.

When should I schedule major renovation or exterior work on a Costa Rica property?

Dry season — December through April — is the window. Exterior painting is the clearest example: painting in rainy season is nearly impossible, as surfaces cannot dry before the next downpour. Any paint applied in high humidity or rain adheres poorly and begins peeling within months. The same applies to exterior concrete work, deck sealing, roof repairs, tile work in outdoor areas, and any construction requiring dry curing time. Roofing specifically should be scheduled for January through March — the deepest dry season — to give maximum time for new materials to cure and seal before May rains arrive. Landscaping projects (tree removal, terracing, retaining wall construction) are also dry season work, as heavy machinery makes a mess of property in wet season and erosion risk is high during active rains. For interior work (tile, painting interior, plumbing, electrical), timing is less critical — these can happen year-round with proper humidity control inside. If you are coordinating major work from Canada, coordinate it for Q1 — the dry season window aligns conveniently with when you likely want to be using the property anyway.

What should a good property manager in Costa Rica be doing for my property during rainy season?

If you are not in-country during rainy season, your property manager should be performing at minimum: weekly visual inspection of the property exterior and interior for water intrusion, roof leaks, or visible mold; dehumidifier operation and emptying (or confirming drainage hoses are flowing); pool maintenance or coordination with pool service; pest monitoring and reporting any unusual activity; security system check and perimeter walk; utility bill payment and account monitoring; and photo documentation of any issues found with immediate notification to you. Monthly, they should do: a more thorough interior inspection including closets, under sinks, and crawl spaces; confirm all drainage is clear; check smoke and CO detector batteries; and provide you with a written or photo report. This level of service is what separates a competent property manager from a property babysitter. If your current manager is doing quarterly check-ins on an unoccupied rainy season property, that is not enough. The problems that develop in 8 unoccupied rainy season weeks (mold, pest infestation, slow leak) cost vastly more to remediate than a weekly visit costs to prevent.

What is the most important thing to do before rainy season starts in Costa Rica?

Roof inspection and gutter clearing, dehumidifier deployment, and pest perimeter treatment — in that order of urgency. The roof inspection should happen in March or April, before the first May rains. Have a local roofing contractor walk the entire roof surface and check: cracked or missing tiles (tile roofs), rust and screw holes (metal sheet roofs), deteriorated caulking around skylights and roof penetrations, and the state of the gutters and downspouts. Clear all gutters of the leaf and debris accumulation from dry season. Install dehumidifiers in bedrooms, the living area, and any room with wood furniture or fabric. Set them to 50–55% relative humidity and empty the collection basins daily (or connect to a drain hose). Have a pest professional treat the perimeter of the property in April — this creates a chemical barrier before the rainy season insect migration begins. These three steps, totaling $400–$700 USD, prevent problems that cost many times more to remediate.

How do I prevent mold in a Costa Rica property that sits empty during rainy season?

Running dehumidifiers is the single most important intervention. The secondary steps amplify their effectiveness: ensure the property is well-sealed (check weatherstripping on doors and windows before you leave), leave interior doors open to allow airflow between rooms, leave closet doors slightly ajar (mold loves the still air inside a closed closet), remove all food items and organic materials that can grow mold, treat mattresses and upholstered furniture with an anti-mold spray before closing, and instruct your property manager to ventilate the property for 30–60 minutes on sunny days — opening doors and windows to flush accumulated humidity. If you have ceiling fans, leave them running on low continuously — airflow dramatically slows mold growth. Dehumidifiers running continuously in occupied rooms plus fans running in unoccupied ones cover most scenarios. If you return and notice a musty smell, act immediately — surface mold is treatable; deep structural mold in drywall, wood framing, or inside mattresses often requires replacement.

What pests are the biggest problem in Costa Rica during rainy season?

Termites are the top structural concern year-round in Costa Rica but activity increases during rainy season when they swarm. A professional perimeter treatment before rainy season suppresses termite activity, but a full termite inspection of any older wooden structure should be annual. Ants (including leaf-cutter ants and biting fire ants) increase dramatically at rainy season start as flooded ground forces them to higher ground — including inside your property. Cockroaches follow the same pattern. In beach properties, sand fleas (no-see-ums) can be severe on Caribbean coast properties during certain wind conditions. Scorpions are present in many dry and transitional forest zones in Costa Rica — Guanacaste properties particularly — and hiding in shoes and damp areas during rainy season. Snakes increase in visibility during rainy season as they move to higher ground; this affects garden maintenance and requires alertness when clearing vegetation. These are manageable with awareness and treatment, not reasons to avoid Costa Rica, but new owners from Canada consistently underestimate the insect pressure.

What special maintenance does a pool need during Costa Rica's dry and rainy seasons?

Dry season (December–April) in Costa Rica brings intense sun and lower humidity. Evaporation increases, chlorine burns off faster due to UV intensity, and algae growth is slower but dust and debris accumulate more. During dry season, increase chlorine dosing frequency, monitor water level and top up more often, clean the pool filter more frequently due to dust accumulation, and clean the tile line regularly as mineral deposits concentrate faster. During rainy season, rainfall dilutes the pool chemistry constantly. Every heavy rainstorm effectively performs a partial water change, requiring re-balancing of pH and alkalinity. Heavy organic debris (leaves, insects, frogs) increase the chlorine demand significantly. A pool service every 1–2 weeks during rainy season is standard; monthly during dry season may be sufficient for a clean-running pool. If your property sits unoccupied through peak rainy season (September–November), arrange for a pool service to visit and treat at least every two weeks or the pool will turn green, requiring an expensive shock treatment and filter cleaning.

When should I schedule major renovation or exterior work on a Costa Rica property?

Dry season — December through April — is the window. Exterior painting is the clearest example: painting in rainy season is nearly impossible, as surfaces cannot dry before the next downpour. Any paint applied in high humidity or rain adheres poorly and begins peeling within months. The same applies to exterior concrete work, deck sealing, roof repairs, tile work in outdoor areas, and any construction requiring dry curing time. Roofing specifically should be scheduled for January through March — the deepest dry season — to give maximum time for new materials to cure and seal before May rains arrive. Landscaping projects (tree removal, terracing, retaining wall construction) are also dry season work, as heavy machinery makes a mess of property in wet season and erosion risk is high during active rains. For interior work (tile, painting interior, plumbing, electrical), timing is less critical — these can happen year-round with proper humidity control inside. If you are coordinating major work from Canada, coordinate it for Q1 — the dry season window aligns conveniently with when you likely want to be using the property anyway.

What should a good property manager in Costa Rica be doing for my property during rainy season?

If you are not in-country during rainy season, your property manager should be performing at minimum: weekly visual inspection of the property exterior and interior for water intrusion, roof leaks, or visible mold; dehumidifier operation and emptying (or confirming drainage hoses are flowing); pool maintenance or coordination with pool service; pest monitoring and reporting any unusual activity; security system check and perimeter walk; utility bill payment and account monitoring; and photo documentation of any issues found with immediate notification to you. Monthly, they should do: a more thorough interior inspection including closets, under sinks, and crawl spaces; confirm all drainage is clear; check smoke and CO detector batteries; and provide you with a written or photo report. This level of service is what separates a competent property manager from a property babysitter. If your current manager is doing quarterly check-ins on an unoccupied rainy season property, that is not enough. The problems that develop in 8 unoccupied rainy season weeks (mold, pest infestation, slow leak) cost vastly more to remediate than a weekly visit costs to prevent.

Seasonal Property Maintenance in Costa Rica: A Canadian Owner's Calendar

Reviewed on March 2026 by the Compass Abroad editorial team

Costa Rica has two seasons with distinct maintenance demands. April/May rainy season prep — roof, gutters, dehumidifiers ($200–$400 each), pest treatment — is the most critical window of the year. Neglect it and you return to mold, structural leaks, and an insect infestation. Dry season (December–April) focuses on irrigation, exterior work, and pool chemistry. Year-round: property manager oversight, security checks, insurance renewal.

The mistakes Canadian owners make in Costa Rica are almost always seasonal in nature — they buy in dry season, when everything looks beautiful and maintenance-free, and return in rainy season to discover what four months of unmanaged tropical climate does to an unoccupied property.

Key Takeaways

Costa Rica's rainy season runs May through November, with the heaviest rainfall typically in September and October. Dry season runs December through April. Pacific coast properties experience this pattern most distinctly; Caribbean coast receives year-round rain but heavier in the north during the dry season.
Pre-rainy season prep (April/May) is the most critical maintenance window of the year. Roof inspection, gutter cleaning, dehumidifier deployment, pest perimeter treatment, and drain clearing should all be completed before the rains begin. Skipping this invites mold, structural water damage, and insect infestations within weeks.
Dehumidifiers are not optional in coastal Costa Rica — they are infrastructure. Properties that sit unoccupied during rainy season without dehumidifiers running develop mold within 4–8 weeks, often irreversibly damaging mattresses, wooden furniture, books, and fabric. Budget $200–$400 CAD per unit and plan for 1–2 units per property.
Mold remediation in Costa Rica is expensive and not always fully successful — prevention is dramatically cheaper than treatment. A mid-rainy-season mold outbreak in an unoccupied property can result in $2,000–$8,000 CAD in remediation costs plus replacement of affected furnishings.
Pest pressure increases significantly at the start of rainy season as insects seek shelter from rain and flooded ground. A professional perimeter pest treatment ($80–$150 USD) applied in April or May dramatically reduces the volume of insects entering the property during the following six months.
Dry season property maintenance (December–April) focuses on irrigation for gardens and landscaping, pool chemistry adjustment as water evaporates faster and UV intensity increases, dust management, and exterior cleaning. This is also the window for major renovation projects and exterior painting.
Insurance renewal in Costa Rica is typically annual and must be coordinated with your property manager — INS (Instituto Nacional de Seguros) is the dominant insurer, but international underwriters are available for higher-value properties. Do not let coverage lapse between seasons.
Your property manager's role expands dramatically during rainy season for unoccupied properties — they should conduct weekly visual checks, operate dehumidifiers, monitor for roof leaks or water intrusion, and document any issues with photos for your review. If your manager is not willing to do this level of oversight, find one who is.

Key Facts for Canadian Buyers

Dehumidifier (mid-size unit): $200–$400 CAD per unit — plan for 1–2 per property(Costa Rica appliance retailers / Canadian import 2026)
Professional pest treatment (perimeter): $80–$150 USD — recommended annually at rainy season start(Costa Rica pest control services 2026)
Gutter cleaning (professional): $50–$100 USD — 1–2 times per year minimum(Costa Rica property maintenance services 2026)
Roof inspection (professional): $100–$200 USD — annual or after major storm(Costa Rica roofing contractors 2026)
Mold remediation (if neglected): $2,000–$8,000 CAD — avoidable with seasonal prevention(Costa Rica remediation contractors 2026)
Annual property insurance (mid-range property): $600–$1,500 USD/year through INS or international insurer(INS Costa Rica / international brokers 2026)

Understanding Costa Rica's Two Seasons

Costa Rica is divided into climatic zones that do not follow a single national pattern. The Pacific coast — where most Canadian buyers focus, including Guanacaste (Tamarindo, Nosara, Sámara), the Central Pacific (Jacó, Dominical, Uvita), and the Southern Zone (Ojochal) — has the classic two-season pattern: a pronounced dry season from December through April and a pronounced rainy season from May through November.

The Central Valley (San José, Escazú, Heredia, Cartago) has a more moderate year-round climate with a less extreme dry season and a rainy season with afternoon showers rather than all-day downpours. The Caribbean coast (Puerto Viejo, Cahuita, Tortuguero) is wet year-round but experiences a relative dry season in September–October and February–March that is counterintuitive — the reverse of the Pacific.

For most Canadian property buyers, the Pacific coast pattern is the relevant one: six months of glorious dry weather (when Canadians are most likely to visit), six months of heavy rain and high humidity (when properties are often unoccupied). That unoccupied rainy season is where maintenance discipline makes or breaks a property.

April–May: The Pre-Rainy Season Preparation Window

This is the most important maintenance window of the year for an unoccupied property. Complete everything on this list before May 15. The first serious rains of the season are diagnostic — if your roof has a vulnerable spot, the first heavy downpour reveals it. You want to find that vulnerability proactively, not receive a panicked message from your property manager with a photo of a soaked bedroom floor.

Roof inspection: Have a local contractor walk the entire roof. For tile roofs: check for cracked, slipped, or missing tiles; check all ridgeline capping; inspect the pointing (mortar) between tiles at ridges and hips. For metal sheet roofs: check all screw penetrations for rubber washer integrity (they deteriorate and allow water infiltration); look for rust holes, particularly around seams; inspect flashing around any roof penetrations (plumbing vents, electrical conduits, skylights). Cost: $100–$200 USD for a thorough inspection from a qualified roofer.

Gutter and drainage clearing:Dry season deposits six months of leaf litter, insect nests, and tree debris in gutters. A clogged gutter in a first heavy downpour means roof overflow, water pooling against the foundation, and water intrusion at the fascia. Clear all gutters; confirm all downspouts drain freely away from the foundation; clear the property's storm drains of dry season sediment accumulation.

Dehumidifier deployment: Plug in and test all units before you leave. Set to 50–55% relative humidity. Connect drainage hoses to a sink or floor drain if available — emptying collection bins requires daily attention that your property manager may not provide reliably. Place units in bedrooms (especially those with wooden furniture or mattresses), the main living area, and any room with significant fabric or books. Do not place dehumidifiers in closets — leave closet doors slightly open so the unit in the adjacent room can draw moisture from the closet space.

Pest perimeter treatment: Have a licensed pest control company apply a residual insecticide treatment to the full perimeter of the building, including under the foundation edge, around window and door frames, and at all utility penetrations. This creates a chemical barrier that dramatically reduces insect ingress at the start of rainy season when ants, cockroaches, and termite swarms are displaced from flooded ground. Cost: $80–$150 USD, annually.

Seal exterior gaps: Walk the exterior of the property looking for gaps around window frames, door thresholds, utility penetrations, and foundation cracks. Seal with outdoor-rated silicone or expanding foam. A gap large enough for a finger is large enough for a scorpion; a gap large enough for a business card is large enough for most tropical insects to enter in numbers.

June–November: Managing an Unoccupied Property Through Rainy Season

If you are not in-country during rainy season, your property manager becomes the operational layer that determines whether your preparation work holds or whether problems compound. Establish a clear inspection protocol with your manager before you leave.

Weekly visits: Your manager should physically enter the property weekly — not a drive-by. Interior check: smell for musty odors (early mold indicator), visual check of all ceilings for water stains, dehumidifier status (running, reservoir not overflowing), check for ant or cockroach activity. Exterior check: gutters clear, no pooling water against foundation, no visible roof damage from recent storms.

Post-storm checks: After any tropical storm or particularly heavy rainstorm, an additional inspection is warranted. Tropical downpours in September and October regularly deliver 100–200mm of rain in a few hours — enough to overwhelm a marginal roof repair or clog a partially cleared gutter. Your manager should document any post-storm issues immediately with photos and contact you.

Ventilation on sunny days: When the sun returns after a rainy period, instruct your manager to open windows and doors for 30–60 minutes to flush accumulated humidity. This simple intervention, done after each significant rain, dramatically slows surface mold development in rooms not directly served by a dehumidifier.

December–April: Dry Season Maintenance Priorities

Dry season brings a different set of maintenance demands. The property is more likely to be occupied (this is when Canadians visit), making daily upkeep more visible but also more natural. The major dry season tasks:

Garden and landscaping irrigation:Guanacaste's dry season is genuinely dry — brown hills, parched soil, winds that desiccate. Any garden or landscaping that was installed or grew during rainy season requires irrigation to survive dry season. An automated drip irrigation system with a timer reduces the labor burden significantly. Mature trees and established native vegetation (locally adapted dry forest species) are largely self-sufficient; exotic imports and tropical flowering plants need regular water. If your property manager is responsible for this during your absence, make sure water schedule, timer access, and plant priorities are documented.

Exterior painting and repairs: The dry season window — particularly January through March — is when exterior painting, concrete patching, deck sealing, and any surface treatments should occur. Everything cures properly. New caulking around windows and doors applied in January will be fully cured before May rains. Tile work on outdoor terraces can be grouted and sealed. This is also the window for roof repairs identified during your pre-rainy-season inspection.

Pool chemistry management in dry season: High UV intensity and low rainfall mean pool water chemistry behaves differently than rainy season. Chlorine burns off faster under the tropical sun; water levels drop from evaporation; dust and pollen from the dry landscape accumulate on the water surface. Increase chlorine dosing frequency, clean the tile line regularly, run the filter longer per day (10–12 hours versus 8 during rainy season), and top up water level weekly as evaporation exceeds precipitation.

Dust management:Guanacaste's dry season produces significant dust from dirt roads and bare fields. Air filters in AC units collect more debris and should be cleaned monthly. Interior floors and surfaces require more frequent cleaning. Window screens benefit from a wash in January to remove the cumulative dry season dust load.

Year-Round Maintenance: Security, Insurance, and Oversight

Security: An unoccupied property is a target regardless of season. Costa Rica has experienced increases in property crime in some tourist areas, and a dark, obviously vacant property is a signal. Your property manager should vary the hours of lighting to suggest occupancy; an alarm system with monitoring provides response capability; exterior security lighting with motion sensors is a cost-effective deterrent. If you use a rental management service, occupancy during rainy season (long-stay surf travelers, digital nomads) both generates income and solves the vacancy signal problem.

Insurance renewal: Costa Rica property insurance is typically annual through INS (Instituto Nacional de Seguros, the state insurer) or through international underwriters for higher-value properties. Your property manager should have calendar reminders for your renewal date and confirm coverage continuation with you before expiry. Do not allow a lapse between seasons — a gap of even two weeks without coverage during a storm or earthquake could be catastrophic for an uninsured loss. Keep a copy of your policy documents digitally accessible from Canada.

Utility accounts:CNFL (electricity) and AyA (water) accounts should be in your name or your property manager's name, not your contractor's. Automatic bill payment prevents disconnection during the months you are not watching. A disconnected electricity account in a property with a refrigerator and dehumidifiers running creates a cascade of problems. Confirm bill payment protocols with your manager.

For comprehensive guidance on managing a Costa Rica property remotely, see our guide on finding and managing a property manager. The principles apply equally to Costa Rica and Mexico.

Frequently Asked Questions

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