Last frost date in Bothell, WA

Average last frost
March 8

The average last frost in Bothell is March 8. By March 29 the chance of another 32°F night drops to 1 in 10. The first fall frost usually arrives about November 23, which leaves 259 frost-free days. An early freeze before November 4 happens one year in ten.

Safe after (10% risk)
Mar 29
Average first frost
Nov 23
Frost-free season
259 days
Hard freeze (28°F) ends
Feb 11
Next 6 nights in Bothell

Frost possible in low spots Fri night, low 36°F

Earlier than usual: the average first frost here is November 23.

National Weather Service forecast, updated Oct 22, 12:57 UTC

  1. ThuOct 2241°
  2. FriOct 2336°possible frost
  3. SatOct 2439°
  4. SunOct 2540°
  5. MonOct 2640°
  6. TueOct 2739°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Mar 8First frost Nov 23259 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND259 frost-free days
Frost risk through the year at Seattle Sand Pt Weather Office, 6.4 miles from Bothell.

Planting calendar for Bothell

Windows count forward or back from the average frost dates above. Click a crop for dates across Washington.

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
Warm-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
TomatoesMar 15–Mar 29
PumpkinsMar 22–Apr 5
SunflowersMar 8–Mar 29
CucumbersMar 22–Mar 29
CornMar 15–Mar 29
Sweet potatoesMar 29–Apr 12
WatermelonMar 22–Apr 5
Green beansMar 15–Apr 5
ZucchiniMar 15–Mar 29
OkraMar 29–Apr 12
PeppersMar 22–Apr 5
BasilMar 15–Mar 29
Butternut squashMar 15–Mar 29
CantaloupeMar 22–Apr 5
EggplantMar 22–Apr 5
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesFeb 8–Feb 22
OnionsJan 25–Feb 15
CarrotsFeb 15–Mar 22
LettuceFeb 22–Mar 15
BroccoliFeb 8–Feb 22
BeetsFeb 8–Mar 22
PeasJan 25–Feb 8
CabbageFeb 8–Feb 22
RadishesFeb 1–Mar 15
Brussels sproutsFeb 22–Mar 8
SpinachJan 25–Feb 15
CilantroFeb 22–Mar 15
KaleFeb 8–Feb 22
Collard greensFeb 8–Feb 22
TurnipsFeb 8–Feb 22
DillMar 8–Mar 22
CeleryMar 15–Mar 22
CauliflowerFeb 22–Mar 8
LeeksFeb 22–Mar 8
Swiss chardFeb 22–Mar 22
ParsleyFeb 22–Mar 15
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsNov 9–Dec 14
GarlicOct 15–Nov 30
Daffodil bulbsOct 15–Nov 30
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesFeb 8–Feb 22
AsparagusFeb 8–Feb 22

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FFeb 13Mar 8Mar 29Nov 4Nov 23Dec 16
Hard freeze, 28°FDec 27Feb 11Mar 1Nov 17Dec 11Jan 17

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 Seattle Sand Pt Weather Office (USW00094290) sits 6.4 miles from the center of Bothell at 60 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 Bothell, WA?

The average last frost date in Bothell is March 8, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after March 29.

When is the first frost in Bothell?

The first frost in fall usually comes around November 23. One year in ten it arrives before November 4.

How long is the growing season in Bothell?

About 259 days between the average last and first frost.

When should I plant tomatoes in Bothell?

Plant tomato seedlings outside from March 15 to March 29. Start seeds indoors six to eight weeks earlier.

Nearby in Washington

All 76 cities in Washington