Roche Harbor, WA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Roche Harbor, a community in San Juan County, Washington.
Overnight
51°F
Mostly Cloudy
Mostly cloudy, with a low around 51. Wind around 0 mph.
7-day forecast for Roche Harbor
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 51°F | Mostly Cloudy | 0 mph | 0% |
| Saturday | 68°F | Partly Sunny | 2 mph SSE | 0% |
| Saturday Night | 50°F | Partly Cloudy | 2 mph SSE | 0% |
| Sunday | 67°F | Partly Sunny | 2 mph NW | 0% |
| Sunday Night | 51°F | Partly Cloudy | 1 mph SW | 0% |
| Monday | 70°F | Mostly Sunny | 2 mph SSW | 0% |
| Monday Night | 51°F | Partly Cloudy | 2 mph WSW | 0% |
| Tuesday | 69°F | Mostly Sunny | 1 to 5 mph SW | 0% |
| Tuesday Night | 51°F | Mostly Cloudy | 5 mph SW | 6% |
| Wednesday | 66°F | Partly Sunny | 5 mph S | 12% |
| Wednesday Night | 51°F | Mostly Cloudy | 3 mph W | 11% |
| Thursday | 65°F | Partly Sunny | 2 to 6 mph NNW | 14% |
| Thursday Night | 50°F | Mostly Cloudy | 5 mph WNW | 14% |
| Friday | 65°F | Mostly Sunny | 7 mph NW | 10% |
Forecast source: National Weather Service (api.weather.gov) for Roche Harbor (48.607, -123.131). Updated through the day.
Growing snapshot for Roche Harbor
Last spring frost
Mar 26
First fall frost
Nov 10
Growing season
230 days
Hardiness zone
9a
More local growing data for Roche Harbor: nearby ZIP 98250 weather · frost dates · planting calendar · Washington frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Friday Harbor Ap, Wa (3.6 mi from Roche Harbor). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.