Grand Mound, WA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Grand Mound, a community in Lewis County, Washington.
Today
76°F
Areas Of Fog then Mostly Sunny
Areas of fog before 10am. Mostly sunny, with a high near 76. North wind 0 to 5 mph.
7-day forecast for Grand Mound
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 76°F | Areas Of Fog then Mostly Sunny | 0 to 5 mph N | 0% |
| Tonight | 45°F | Areas Of Fog | 0 to 3 mph NW | 0% |
| Monday | 75°F | Areas Of Fog then Mostly Cloudy | 0 to 6 mph NW | 0% |
| Monday Night | 50°F | Partly Cloudy | 0 to 6 mph WSW | 0% |
| Tuesday | 71°F | Partly Sunny | 0 to 8 mph SW | 0% |
| Tuesday Night | 46°F | Partly Cloudy | 1 to 8 mph SW | 4% |
| Wednesday | 69°F | Partly Sunny | 1 to 5 mph WSW | 4% |
| Wednesday Night | 45°F | Mostly Cloudy | 0 to 5 mph NNW | 2% |
| Thursday | 67°F | Mostly Cloudy then Slight Chance Light Rain | 0 to 5 mph NNE | 23% |
| Thursday Night | 47°F | Chance Light Rain | 0 to 3 mph NNE | 45% |
| Friday | 64°F | Chance Light Rain | 0 to 6 mph SW | 45% |
| Friday Night | 44°F | Slight Chance Light Rain then Mostly Cloudy | 2 to 6 mph SW | 16% |
| Saturday | 66°F | Mostly Sunny | 5 mph SSW | 8% |
| Saturday Night | 43°F | Partly Cloudy | 0 to 5 mph NNW | 10% |
Forecast source: National Weather Service (api.weather.gov) for Grand Mound (46.800, -123.011). Updated through the day.
Growing snapshot for Grand Mound
Last spring frost
Apr 22
First fall frost
Oct 27
Growing season
188 days
Hardiness zone
8b
More local growing data for Grand Mound: nearby ZIP 98544 weather · frost dates · planting calendar · Washington frost dates
Nearby towns & communities
Ashford
Centralia
Chehalis
Fords Prairie
Morton
Mossyrock
Napavine
Onalaska
Packwood
Pe Ell
Toledo
Vader
Winlock
Climate data from the nearest NOAA station, Centralia, Wa (3.8 mi from Grand Mound). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.