Prosser, WA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Prosser, a city in Benton County, Washington.
Tonight
32°F
Patchy Fog
Patchy fog. Mostly clear. Low around 32, with temperatures rising to around 34 overnight. Wind around 0 mph.
7-day forecast for Prosser
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 32°F | Patchy Fog | 0 mph | 1% |
| Wednesday | 54°F | Patchy Fog | 0 to 3 mph S | 2% |
| Wednesday Night | 36°F | Chance Rain Showers | 2 mph S | 48% |
| Thursday | 59°F | Patchy Fog then Mostly Sunny | 3 mph SW | 7% |
| Thursday Night | 34°F | Patchy Fog | 2 mph SW | 3% |
| Friday | 57°F | Patchy Fog then Mostly Cloudy | 2 mph S | 7% |
| Friday Night | 36°F | Mostly Cloudy then Patchy Fog | 2 mph S | 7% |
| Saturday | 59°F | Patchy Fog then Mostly Sunny | 2 mph NE | 1% |
| Saturday Night | 37°F | Mostly Cloudy | 3 mph NW | 2% |
| Sunday | 61°F | Partly Sunny | 2 to 6 mph SW | 2% |
| Sunday Night | 36°F | Mostly Cloudy | 2 mph W | 1% |
| Monday | 57°F | Partly Sunny | 1 mph N | 6% |
| Monday Night | 35°F | Mostly Cloudy then Slight Chance Rain Showers | 1 mph NW | 17% |
| Tuesday | 60°F | Slight Chance Rain Showers | 2 mph SW | 20% |
Forecast source: National Weather Service (api.weather.gov) for Prosser (46.209, -119.768). Updated through the day.
Growing snapshot for Prosser
Last spring frost
Apr 14
First fall frost
Oct 22
Growing season
189 days
Hardiness zone
7b
More local growing data for Prosser: nearby ZIP 99350 weather · frost dates · planting calendar · Washington frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Prosser, Wa (4.2 mi from Prosser). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.