Last frost date in Walla Walla, WA
Expect the last frost in Walla Walla around March 27. Frost after April 22 happens in only one year out of ten. The first fall frost usually arrives about October 31, which leaves 219 frost-free days. An early freeze before October 15 happens one year in ten.
- Safe after (10% risk)
- Apr 22
- Average first frost
- Oct 31
- Frost-free season
- 219 days
- Hard freeze (28°F) ends
- Mar 4
Frost likely Fri night, low 32°F
Earlier than usual: the average first frost here is October 31.
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2239°
- FriOct 2332°frost
- SatOct 2434°possible frost
- SunOct 2534°possible frost
- MonOct 2633°possible frost
- TueOct 2733°possible frost
Planting calendar for Walla Walla
Windows count forward or back from the average frost dates above. Click a crop for dates across Washington.
TomatoesApr 3–Apr 17
PumpkinsApr 10–Apr 24
SunflowersMar 27–Apr 17
CucumbersApr 10–Apr 17
CornApr 3–Apr 17
Sweet potatoesApr 17–May 1
WatermelonApr 10–Apr 24
Green beansApr 3–Apr 24
ZucchiniApr 3–Apr 17
OkraApr 17–May 1
PeppersApr 10–Apr 24
BasilApr 3–Apr 17
Butternut squashApr 3–Apr 17
CantaloupeApr 10–Apr 24
EggplantApr 10–Apr 24
PotatoesFeb 27–Mar 13
OnionsFeb 13–Mar 6
CarrotsMar 6–Apr 10
LettuceMar 13–Apr 3
BroccoliFeb 27–Mar 13
BeetsFeb 27–Apr 10
PeasFeb 13–Feb 27
CabbageFeb 27–Mar 13
RadishesFeb 20–Apr 3
Brussels sproutsMar 13–Mar 27
SpinachFeb 13–Mar 6
CilantroMar 13–Apr 3
KaleFeb 27–Mar 13
Collard greensFeb 27–Mar 13
TurnipsFeb 27–Mar 13
DillMar 27–Apr 10
CeleryApr 3–Apr 10
CauliflowerMar 13–Mar 27
LeeksMar 13–Mar 27
Swiss chardMar 13–Apr 10
ParsleyMar 13–Apr 3
Tulip bulbsOct 17–Nov 21
GarlicOct 10–Nov 14
Daffodil bulbsOct 3–Nov 14
StrawberriesFeb 27–Mar 13
AsparagusFeb 27–Mar 13Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | Mar 3 | Mar 27 | Apr 22 | Oct 15 | Oct 31 | Nov 17 |
| Hard freeze, 28°F | Feb 9 | Mar 4 | Mar 27 | Oct 25 | Nov 14 | Dec 4 |
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 Walla Walla Regional Airport (USW00024160) sits 3.1 miles from the center of Walla Walla at 1,166 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 Walla Walla, WA?
The average last frost date in Walla Walla is March 27, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after April 22.
When is the first frost in Walla Walla?
The first frost in fall usually comes around October 31. One year in ten it arrives before October 15.
How long is the growing season in Walla Walla?
About 219 days between the average last and first frost.
When should I plant tomatoes in Walla Walla?
Plant tomato seedlings outside from April 3 to April 17. Start seeds indoors six to eight weeks earlier.
Nearby in Washington
- PascoApr 27
- KennewickMar 28
- RichlandApr 6
- PullmanMay 6
- Moses LakeApr 27
- YakimaApr 8
- SpokaneApr 26
- Spokane ValleyApr 26
- EllensburgMay 8
- WenatcheeApr 4
- Maple ValleyApr 20
- Bonney LakeApr 11