Castle Rock, WA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Castle Rock, a city in Cowlitz County, Washington.
Tonight
38°F
Areas Of Fog
Areas of fog before 3am. Mostly clear. Low around 38, with temperatures rising to around 40 overnight. Southeast wind around 2 mph.
7-day forecast for Castle Rock
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 38°F | Areas Of Fog | 2 mph SE | 2% |
| Wednesday | 59°F | Mostly Cloudy then Light Rain Likely | 3 mph S | 70% |
| Wednesday Night | 45°F | Light Rain | 2 to 6 mph S | 94% |
| Thursday | 58°F | Slight Chance Light Rain then Partly Sunny | 3 mph S | 22% |
| Thursday Night | 43°F | Areas Of Fog then Chance Light Rain | 0 to 3 mph SSE | 52% |
| Friday | 57°F | Light Rain Likely | 2 to 6 mph SSE | 66% |
| Friday Night | 47°F | Light Rain Likely | 2 mph SSE | 56% |
| Saturday | 64°F | Partly Sunny then Chance Light Rain | 3 mph S | 28% |
| Saturday Night | 49°F | Light Rain | 2 to 10 mph S | 81% |
| Sunday | 56°F | Chance Light Rain | 0 to 6 mph SSW | 49% |
| Sunday Night | 42°F | Slight Chance Light Rain | 2 mph ENE | 15% |
| Monday | 56°F | Chance Light Rain | 2 mph SE | 37% |
| Monday Night | 46°F | Chance Light Rain | 1 to 8 mph SSE | 48% |
| Tuesday | 57°F | Chance Light Rain | 2 to 8 mph SSE | 49% |
Forecast source: National Weather Service (api.weather.gov) for Castle Rock (46.272, -122.904). Updated through the day.
Growing snapshot for Castle Rock
Last spring frost
Apr 8
First fall frost
Nov 5
Growing season
210 days
Hardiness zone
8b
More local growing data for Castle Rock: nearby ZIP 98611 weather · frost dates · planting calendar · Washington frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Longview, Wa (10.7 mi from Castle Rock). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.