Castle Rock, WA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Castle Rock, a city in Cowlitz County, Washington.
Overnight
50°F
Patchy Fog
Patchy fog. Mostly cloudy, with a low around 50. Northeast wind around 1 mph.
7-day forecast for Castle Rock
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 50°F | Patchy Fog | 1 mph NE | 0% |
| Saturday | 78°F | Patchy Fog then Partly Sunny | 1 mph N | 0% |
| Saturday Night | 49°F | Mostly Clear then Patchy Fog | 2 mph NNE | 1% |
| Sunday | 79°F | Mostly Sunny | 2 mph N | 1% |
| Sunday Night | 50°F | Mostly Clear | 2 mph NNW | 0% |
| Monday | 76°F | Patchy Fog then Mostly Sunny | 2 mph NW | 0% |
| Monday Night | 51°F | Partly Cloudy then Patchy Fog | 2 mph NW | 0% |
| Tuesday | 73°F | Patchy Fog then Partly Sunny | 2 mph NW | 0% |
| Tuesday Night | 48°F | Partly Cloudy then Areas Of Fog | 2 mph NW | 1% |
| Wednesday | 72°F | Areas Of Fog then Partly Sunny | 1 mph NNW | 1% |
| Wednesday Night | 49°F | Mostly Cloudy then Patchy Fog | 1 mph NNW | 1% |
| Thursday | 69°F | Patchy Fog then Mostly Cloudy | 2 mph N | 14% |
| Thursday Night | 48°F | Mostly Cloudy | 3 mph NNW | 14% |
| Friday | 68°F | Partly Sunny | 2 mph NNW | 11% |
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 Sep 19, 2026.