Grand Coulee, WA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Grand Coulee, a city in Grant County, Washington.
Today
90°F
Sunny then Patchy Smoke
Patchy smoke after noon. Sunny, with a high near 90. North wind 3 to 7 mph.
7-day forecast for Grand Coulee
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 90°F | Sunny then Patchy Smoke | 3 to 7 mph N | 0% |
| Tonight | 62°F | Patchy Smoke then Haze | 1 to 5 mph W | 0% |
| Wednesday | 96°F | Smoke | 2 to 7 mph S | 0% |
| Wednesday Night | 65°F | Areas Of Smoke then Mostly Clear | 2 to 7 mph SE | 0% |
| Thursday | 100°F | Sunny | 2 to 8 mph SE | 0% |
| Thursday Night | 68°F | Mostly Clear | 2 to 8 mph W | 0% |
| Friday | 99°F | Sunny | 2 to 12 mph W | 0% |
| Friday Night | 67°F | Mostly Clear | 5 to 13 mph W | 0% |
| Saturday | 95°F | Sunny | 3 to 10 mph W | 0% |
| Saturday Night | 65°F | Mostly Clear | 6 to 12 mph W | 0% |
| Sunday | 92°F | Sunny | 5 to 9 mph W | 0% |
| Sunday Night | 64°F | Mostly Clear | 3 to 9 mph W | 0% |
| Monday | 90°F | Sunny | 3 to 8 mph W | 0% |
| Monday Night | 63°F | Mostly Clear | 3 to 8 mph W | 0% |
Forecast source: National Weather Service (api.weather.gov) for Grand Coulee (47.939, -119.002). Updated through the day.
Growing snapshot for Grand Coulee
Last spring frost
Apr 22
First fall frost
Oct 21
Growing season
180 days
Hardiness zone
7a
More local growing data for Grand Coulee: nearby ZIP 99123 weather · frost dates · planting calendar · Washington frost dates
Nearby towns & communities
Beverly
Cascade Valley
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Electric City
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George
Hartline
Krupp
Lakeview
Marine View
Moses Lake
Moses Lake North
Quincy
Royal City
Schwana
Soap Lake
Sunland Estates
Vantage
Warden
Wheeler
Wilson Creek
Climate data from the nearest NOAA station, Coulee Dam 1 Sw, Wa (5.3 mi from Grand Coulee). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.