Union, WA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Union, a community in Mason County, Washington.
Today
56°F
Partly Sunny
Partly sunny. High near 56, with temperatures falling to around 51 in the afternoon. North northeast wind around 2 mph.
7-day forecast for Union
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 56°F | Partly Sunny | 2 mph NNE | 4% |
| Tonight | 39°F | Partly Cloudy then Patchy Fog | 1 mph NNE | 4% |
| Wednesday | 55°F | Patchy Fog then Chance Light Rain | 0 to 5 mph SSW | 52% |
| Wednesday Night | 45°F | Light Rain | 5 to 13 mph SSW | 100% |
| Thursday | 54°F | Chance Light Rain | 7 to 10 mph SW | 26% |
| Thursday Night | 46°F | Light Rain | 7 mph SSW | 90% |
| Friday | 54°F | Light Rain | 5 to 8 mph SSW | 90% |
| Friday Night | 46°F | Chance Light Rain | 1 to 6 mph WSW | 48% |
| Saturday | 57°F | Chance Light Rain | 5 mph SSW | 50% |
| Saturday Night | 48°F | Rain | 5 to 24 mph SSW | 88% |
| Sunday | 54°F | Light Rain Likely | 7 to 18 mph SW | 71% |
| Sunday Night | 43°F | Chance Light Rain | 1 to 7 mph NW | 35% |
| Monday | 53°F | Light Rain Likely | 1 to 6 mph E | 61% |
| Monday Night | 46°F | Rain | 5 to 9 mph SSW | 80% |
Forecast source: National Weather Service (api.weather.gov) for Union (47.348, -123.095). Updated through the day.
Growing snapshot for Union
Last spring frost
Mar 24
First fall frost
Nov 15
Growing season
235 days
Hardiness zone
8b
More local growing data for Union: nearby ZIP 98592 weather · frost dates · planting calendar · Washington frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Cushman Powerhouse #2, Wa (4.7 mi from Union). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.