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Custer, WA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Custer, a community in Whatcom County, Washington.

This Afternoon
70°F
Mostly Sunny
Mostly sunny. High near 70, with temperatures falling to around 68 in the afternoon. West southwest wind around 3 mph.

7-day forecast for Custer

WhenTempForecastWindPrecip
This Afternoon 70°F Mostly Sunny 3 mph WSW 0%
Tonight 49°F Partly Cloudy 2 mph S 0%
Sunday 71°F Mostly Sunny 0 to 5 mph S 0%
Sunday Night 50°F Mostly Cloudy 0 to 3 mph SSW 0%
Monday 69°F Partly Sunny 0 to 5 mph S 0%
Monday Night 50°F Partly Cloudy 1 to 5 mph S 0%
Tuesday 68°F Partly Sunny 1 to 6 mph S 1%
Tuesday Night 49°F Mostly Cloudy then Slight Chance Light Rain 7 mph SSE 22%
Wednesday 66°F Slight Chance Light Rain then Partly Sunny 5 mph S 22%
Wednesday Night 49°F Mostly Cloudy 1 to 5 mph SSE 12%
Thursday 65°F Mostly Cloudy 1 to 6 mph NNE 13%
Thursday Night 48°F Mostly Cloudy then Slight Chance Light Rain 1 to 6 mph NW 22%
Friday 66°F Slight Chance Light Rain 1 to 6 mph NW 22%
Friday Night 47°F Slight Chance Light Rain 6 mph SSE 20%

Forecast source: National Weather Service (api.weather.gov) for Custer (48.913, -122.637). Updated through the day.

Growing snapshot for Custer

Last spring frost
Mar 31
First fall frost
Nov 4
Growing season
219 days
Hardiness zone
8b

More local growing data for Custer: nearby ZIP 98240 weather · frost dates · planting calendar · Washington frost dates

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Climate data from the nearest NOAA station, Blaine, Wa (8.1 mi from Custer). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.