Last frost date in Renton, WA

Average last frost
March 13

Expect the last frost in Renton around March 13. Frost after March 31 happens in only one year out of ten. The first fall frost usually arrives about November 16, which leaves 248 frost-free days. An early freeze before October 29 happens one year in ten.

Safe after (10% risk)
Mar 31
Average first frost
Nov 16
Frost-free season
248 days
Hard freeze (28°F) ends
Feb 13
Next 6 nights in Renton

No frost in the next 6 nights

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

  1. ThuOct 2243°
  2. FriOct 2339°
  3. SatOct 2442°
  4. SunOct 2543°
  5. MonOct 2642°
  6. TueOct 2742°
JanFebMarAprMayJunJulAugSepOctNovDecLast frost Mar 13First frost Nov 16248 frost-free daysBlue: chance of 32°F frost. Green: average frost-free season.JFMAMJJASOND248 frost-free days
Frost risk through the year at Renton Municipal Airport, 1.3 miles from Renton.

Planting calendar for Renton

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 20–Apr 3
PumpkinsMar 27–Apr 10
SunflowersMar 13–Apr 3
CucumbersMar 27–Apr 3
CornMar 20–Apr 3
Sweet potatoesApr 3–Apr 17
WatermelonMar 27–Apr 10
Green beansMar 20–Apr 10
ZucchiniMar 20–Apr 3
OkraApr 3–Apr 17
PeppersMar 27–Apr 10
BasilMar 20–Apr 3
Butternut squashMar 20–Apr 3
CantaloupeMar 27–Apr 10
EggplantMar 27–Apr 10
Cool-season crops
JanFebMarAprMayJunJulAugSepOctNovDec
PotatoesFeb 13–Feb 27
OnionsJan 30–Feb 20
CarrotsFeb 20–Mar 27
LettuceFeb 27–Mar 20
BroccoliFeb 13–Feb 27
BeetsFeb 13–Mar 27
PeasJan 30–Feb 13
CabbageFeb 13–Feb 27
RadishesFeb 6–Mar 20
Brussels sproutsFeb 27–Mar 13
SpinachJan 30–Feb 20
CilantroFeb 27–Mar 20
KaleFeb 13–Feb 27
Collard greensFeb 13–Feb 27
TurnipsFeb 13–Feb 27
DillMar 13–Mar 27
CeleryMar 20–Mar 27
CauliflowerFeb 27–Mar 13
LeeksFeb 27–Mar 13
Swiss chardFeb 27–Mar 27
ParsleyFeb 27–Mar 20
Fall bulbs and garlic
JanFebMarAprMayJunJulAugSepOctNovDec
Tulip bulbsNov 2–Dec 7
GarlicOct 26–Nov 30
Daffodil bulbsOct 19–Nov 30
Perennials
JanFebMarAprMayJunJulAugSepOctNovDec
StrawberriesFeb 13–Feb 27
AsparagusFeb 13–Feb 27

Frost probabilities

ThresholdSpring, 90% chance laterSpring, 50%Spring, 10%Fall, 10% chance earlierFall, 50%Fall, 90%
Light frost, 32°FFeb 19Mar 13Mar 31Oct 29Nov 16Dec 9
Hard freeze, 28°FJan 1Feb 13Mar 6Nov 11Dec 6Jan 9

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 Renton Municipal Airport (USW00094248) sits 1.3 miles from the center of Renton at 29 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 Renton, WA?

The average last frost date in Renton is March 13, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after March 31.

When is the first frost in Renton?

The first frost in fall usually comes around November 16. One year in ten it arrives before October 29.

How long is the growing season in Renton?

About 248 days between the average last and first frost.

When should I plant tomatoes in Renton?

Plant tomato seedlings outside from March 20 to April 3. Start seeds indoors six to eight weeks earlier.

Nearby in Washington

All 76 cities in Washington