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City of Sumas, WASumas, WA 7-Day Night Weather Forecast
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Sumas, WA Weather Forecast
Sumas, WA Weather Forecast Date: 236 PM PDT Fri Sep 18 2026
The area/counties/county of: Lowlands Of Western Whatcom County, including the cities of: Bellingham, Sumas, Blaine, and Lynden.or toggle through each period.
Tonight... Partly cloudy. Lows in the upper 40s to mid 50s. Light wind.
Saturday... Partly sunny. Highs in the mid 60s to lower 70s. Light wind.
Saturday Night... Partly cloudy. Lows near 50. Light wind.
Sunday... Partly sunny in the morning then becoming sunny. Highs in the upper 60s to mid 70s. Light wind.
Sunday Night... Partly cloudy. Lows in the upper 40s to mid 50s. Light wind.
Monday... Mostly sunny. Highs near 70.
Monday Night... Partly cloudy. Lows in the lower 50s.
Tuesday... Partly sunny. Highs in the mid 60s to lower 70s.
Tuesday Night... Partly cloudy. Lows near 50.
Wednesday... Partly sunny. Highs in the mid 60s to lower 70s.
Wednesday Night... Partly cloudy in the evening then becoming mostly cloudy. Lows in the lower 50s.
Thursday... Partly sunny. Highs near 70.
Thursday Night... Mostly cloudy. A slight chance of rain in the evening, then a chance of rain after midnight. Lows in the lower 50s.
POP = Probability of Precipitation
Sumas Radar Loop
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