St. John, WA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. John, a town in Whitman County, Washington.
Tonight
49°F
Mostly Clear
Mostly clear, with a low around 49. South wind around 2 mph.
7-day forecast for St. John
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 49°F | Mostly Clear | 2 mph S | 1% |
| Saturday | 78°F | Sunny | 3 mph SW | 0% |
| Saturday Night | 49°F | Mostly Clear | 2 mph S | 0% |
| Sunday | 82°F | Sunny | 3 mph S | 0% |
| Sunday Night | 50°F | Mostly Clear | 2 mph E | 0% |
| Monday | 82°F | Sunny | 5 mph S | 0% |
| Monday Night | 51°F | Partly Cloudy | 1 to 5 mph S | 0% |
| Tuesday | 78°F | Mostly Sunny | 5 mph S | 0% |
| Tuesday Night | 50°F | Partly Cloudy | 5 mph SW | 0% |
| Wednesday | 74°F | Mostly Sunny | 5 mph S | 0% |
| Wednesday Night | 48°F | Partly Cloudy | 3 mph S | 0% |
| Thursday | 80°F | Mostly Sunny | 5 mph SE | 1% |
| Thursday Night | 50°F | Partly Cloudy | 3 mph SE | 6% |
| Friday | 75°F | Mostly Sunny | 6 mph SW | 10% |
Forecast source: National Weather Service (api.weather.gov) for St. John (47.091, -117.589). Updated through the day.
Growing snapshot for St. John
Last spring frost
Apr 29
First fall frost
Oct 4
Growing season
161 days
Hardiness zone
6b
More local growing data for St. John: nearby ZIP 99171 weather · frost dates · planting calendar · Washington frost dates
Nearby towns & communities
Albion
Clarkston
Clarkston Heights-Vineland
Colfax
Colton
Endicott
Farmington
Garfield
LaCrosse
Lamont
Malden
Oakesdale
Palouse
Pullman
Rosalia
Steptoe
Tekoa
Uniontown
West Clarkston-Highland
Climate data from the nearest NOAA station, St John, Wa (3.1 mi from St. John). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.