Last frost date in Tumwater, WA
Expect the last frost in Tumwater around April 29. Frost after May 15 happens in only one year out of ten. The first fall frost usually arrives about October 14, which leaves 169 frost-free days. An early freeze before September 28 happens one year in ten.
- Safe after (10% risk)
- May 15
- Average first frost
- Oct 14
- Frost-free season
- 169 days
- Hard freeze (28°F) ends
- Apr 5
Frost likely Fri night, low 32°F
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2236°possible frost
- FriOct 2332°frost
- SatOct 2435°possible frost
- SunOct 2536°possible frost
- MonOct 2636°possible frost
- TueOct 2736°possible frost
Planting calendar for Tumwater
Windows count forward or back from the average frost dates above. Click a crop for dates across Washington.
Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Apr 11 | Apr 29 | May 15 | Sep 28 | Oct 14 | Nov 1 |
| Hard freeze, 28°F | Mar 12 | Apr 5 | Apr 29 | Oct 9 | Nov 1 | Nov 24 |
Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.
Where these numbers come from
NOAA station Olympia Airport (USW00024227) sits 1.3 miles from the center of Tumwater at 188 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.
Questions
When is the last frost in Tumwater, WA?
The average last frost date in Tumwater is April 29, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 15.
When is the first frost in Tumwater?
The first frost in fall usually comes around October 14. One year in ten it arrives before September 28.
How long is the growing season in Tumwater?
About 169 days between the average last and first frost.
When should I plant tomatoes in Tumwater?
Plant tomato seedlings outside from May 6 to May 20. Start seeds indoors six to eight weeks earlier.
Nearby in Washington
- OlympiaApr 29
- LaceyApr 29
- LakewoodMar 11
- University PlaceMar 11
- SpanawayApr 11
- ParklandMar 8
- FredericksonApr 11
- TacomaMar 8
- GrahamApr 11
- South HillApr 11
- PuyallupApr 11
- Federal WayMar 8