Whatcom County Climate
Whatcom County, Washington
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
50.0°F
Annual Precip
59.7"
Annual Snowfall
29.7"
Extreme Heat Days
5
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
8a
Minimum winter temperature range for plant survival
1,801
Favors cool-season crops
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Whatcom County
Climate Verdict
Whatcom County has a mild, with an average annual temperature of 50.0°F, very wet conditions receiving 59.7 inches of precipitation annually, rare extreme heat with only 4.85 days above 90°F annually, moderate snowfall of 29.7 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are cold, with January averaging 37.0°F. summers are pleasantly cool with July averaging 64.6°F. The climate is remarkably stable year-round, with only a 28°F difference between January and July. December is typically the coldest month and August the warmest.
Outdoor & Gardening Guidance
Growing season and gardening data is currently limited for Whatcom County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.
Regional Context
Whatcom County closely matches the Washington statewide average temperature of 49.9°F, it is also noticeably wetter, receiving 21.2 inches more precipitation than the state average.
Climate Profile
About Whatcom County Weather
Whatcom’s Cool and Wet Border Climate
Whatcom County averages 50.0°F annually, which is slightly cooler than the national median. The region is known for its high precipitation and moderate maritime temperatures.
Perfectly Aligned with State Averages
The county's average temperature of 50.0°F is nearly identical to the Washington state average of 49.9°F. However, its 59.7 inches of precipitation is much higher than the state's 38.5-inch average.
Snowier than the Southern Puget Sound
Whatcom sees 29.7 inches of snow annually, which is vastly more than Thurston County’s 3.9 inches. This is due to its northern position and proximity to cold mountain air currents.
Mild Summers and Snowy Winters
The county only experiences 5 extreme heat days per year, with summer averages staying cool at 63.0°F. Winters are chilly, averaging 37.6°F with significant seasonal snowfall.
Prepare for Snow and Rain
Residents need to be ready for both 59.7 inches of rain and nearly 30 inches of snow. While AC is rarely urgent due to few 90°F days, reliable heating and waterproof layers are mandatory.
Frequently Asked Questions
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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.
Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.