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Spokane, Washington mold guide

Mold Guide for Spokane, Washington

Local mold risk drivers, seasonal priorities, and next steps for homeowners and renters in Spokane.

State law data last updated: 2026-02-02

Overview

Annual precipitation in Spokane averages 16.4 inches with temperatures near 48.6 F, so the area experiences infrequent rain but high sensitivity to leaks when storms hit.

Spokane is east of the Cascades with colder winters, warmer summers, and much lower precipitation than western Washington.

Code Enforcement uses inspection districts and focused compliance efforts to address property maintenance issues.

This guide highlights local moisture drivers, seasonal risk, and prevention steps. For legal rights and landlord obligations, review the Washington mold laws guide.

Sources: [Washington - Climate | Britannica] | [Spokane Code Enforcement Inspection Districts] | [NOAA Climate Normals - SPOKANE INTL AP, WA US]

Action Checklist

Get free access to the full guide

8-step checklist for immediate action

Spokane Home Inspection Checklist

Common construction types in Spokane affect where moisture problems develop. Here is how local building patterns shape what to inspect.

In Spokane, code Enforcement organizes inspection districts to manage property maintenance complaints.

Focused compliance efforts target common property maintenance violations across the districts.

Sources: [Spokane Code Enforcement Inspection Districts]

  • Spokane gets only 16.4 inches of rain per year, but each storm tests roof flashings and window seals. Inspect promptly.
  • Roof flashing, gutters, and downspout extensions.
  • Attic insulation and ventilation near eaves.
  • Window frames and sills with condensation.
  • Basement walls, sump pits, and floor drains.
  • Plumbing lines in exterior walls that can freeze and leak.
  • Bathroom exhaust fans and vent ducts.
  • HVAC condensate lines and drip pans.

Sources: [EPA Mold, Moisture, and Your Home] | [NOAA Climate Normals - SPOKANE INTL AP, WA US]

Warning Signs of Mold in Spokane

Watch for these signs that moisture is lingering in Spokane homes and rentals:

  • In Spokane, where average temperatures reach 48.6 F, condensation on windows during warmer months points to a moisture imbalance indoors.
  • Condensation that returns on windows each morning.
  • Musty odors after snowmelt or heavy rain.
  • Peeling paint near baseboards or window trim.
  • Dark spotting near ceiling corners.
  • Soft drywall around tubs or showers.

Sources: [EPA Mold, Moisture, and Your Home] | [NOAA Climate Normals - SPOKANE INTL AP, WA US]

Mold Risk Factors in Spokane

These are the most common moisture drivers for homes and rentals in Spokane:

  • Annual precipitation in Spokane averages only 16.4 inches, making indoor moisture sources like plumbing and cooling systems the main concern.
  • Cold winters drive window and attic condensation.
  • Snow and ice can lead to roof leaks and ice dams.
  • Freeze-thaw cycles stress roof flashing and exterior joints.
  • Summer heat increases cooling loads and condensate.
  • Dry spells can hide slow leaks until fall rains.

Sources: [Washington - Climate | Britannica] | [EPA Mold, Moisture, and Your Home] | [NOAA Climate Normals - SPOKANE INTL AP, WA US]

Spokane Seasonal Risk Calendar

Winter

At 48.6 F annually, long heating seasons push warm air against cold surfaces. Keep air moving to reduce condensation.

Spring

Thaw and rain keep basements damp. Check drainage.

Summer

Cool summers still bring rain. Inspect roof edges after storms.

Fall

Temperature swings return. Watch for attic condensation.

Sources: [Washington - Climate | Britannica] | [NOAA Climate Normals - SPOKANE INTL AP, WA US]

Spokane Moisture Playbook

Use this short playbook to stay ahead of common moisture problems in Spokane.

After a Leak

Stop the leak, remove wet materials within 24 to 48 hours, and dry the area with airflow.

Monthly Maintenance

Inspect under sinks, clear condensate lines, and log indoor humidity.

Seasonal Tune Up

Seal window gaps and check drainage before storm season. At 16.4 inches of annual rain, even one storm can introduce hidden moisture.

Sources: [EPA Mold, Moisture, and Your Home] | [NOAA Climate Normals - SPOKANE INTL AP, WA US]

Mold Prevention in Spokane

Use these priorities to keep indoor humidity low and avoid recurring growth:

  • Even 16.4 inches of yearly precipitation can cause problems if window seals and door gaps are not maintained before storms.
  • Maintain indoor humidity between 30 and 50 percent.
  • Dry wet materials within 24 to 48 hours.
  • Vent bathrooms and kitchens outdoors.
  • Clear gutters and direct downspouts away from foundations.
  • Inspect roof flashing and window seals before winter.
  • Service HVAC condensate drains annually.

Sources: [EPA Mold, Moisture, and Your Home] | [NOAA Climate Normals - SPOKANE INTL AP, WA US]

State Laws and Rights

Washington mold law snapshot

Washington has mold-specific rules in addition to general habitability standards.

Washington law establishes an implied warranty of habitability through RCW 59.18.060. Landlords must maintain premises fit for human habitation at all times during the tenancy. This includes keeping the property in substantial compliance with applicable codes affecting tenant health or safety, maintaining structural components in reasonably good repair, providing adequate weatherproofing, and maintaining plumbing, heating, and ventilation systems in reasonably good working order. While mold itself is not explicitly listed as a habitability violation, landlords must fix the conditions that cause mold: water leaks, moisture problems, and inadequate ventilation.

Use the full Washington guide for tenant rights, landlord responsibilities, and remedies.

Frequently Asked Questions

What are the first signs of mold in a Spokane home?
Musty odors, condensation on windows, peeling paint, and dark spots near vents or ceilings are common early signs. If symptoms persist after cleaning, schedule an inspection.
When should I hire a mold professional in Spokane?
If the affected area is larger than about 10 square feet, if growth returns after cleaning, or if anyone has health symptoms, hire a pro. Use the DIY vs pro guide to decide.
How does salt air affect mold growth in Spokane?
Salt air keeps humidity high and can wear down seals and caulk. Inspect exterior joints and ventilate crawl spaces regularly. See our prevention guide.
Are coastal homes in Spokane more prone to mold?
Fog, wind-driven rain, and elevated humidity put coastal homes at higher risk. Focus on ventilation, dehumidification, and exterior maintenance. Check our room-by-room guide.
What should I do about mold after a Spokane storm?
Stop the water source, remove wet materials within 48 hours, and run fans and dehumidifiers. Photograph damage for insurance. See the storm recovery guide.
Does Spokane humidity make mold more likely?
High outdoor humidity slows drying after leaks, which raises risk. Active ventilation and dehumidification are key. Review prevention priorities for humid climates.