FrostDateByZip

Frost dates for 99006Deer Park, WA

The average last spring frost in Deer Park is May 22 and the average first fall frost is September 14, giving a typical growing season of about 112 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost
May 22

Safer after Jun 15 (1-in-10 risk)

Average first fall frost
Sep 14

Possible by Aug 28 (1-in-10 risk)

Growing season
112 days

Last frost typically in 208 days

Frost risk by date

NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.

Spring dates: chance of a frost AFTER the date. Fall dates: chance of a frost BEFORE the date.
TemperatureLast spring: 90% / 50% / 10% chanceFirst fall: 10% / 50% / 90% chanceGrowing season (50%)Years with at least one
Light frost (36°F)——72 days100%
Frost / freeze (32°F)May 2 · May 22 · Jun 15Aug 28 · Sep 14 · Oct 1112 days100%
Hard freeze (28°F)Apr 18 · May 3 · May 21Sep 14 · Sep 29 · Oct 14146 days100%

Planting calendar for Deer Park

Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.

CropTaskWindow
TomatoesStart seeds indoorsApr 21 – Jun 27
TomatoesTransplant outdoorsJun 7 – May 25
PeppersStart seeds indoorsApr 21 – May 22
PeppersTransplant outdoorsJun 21 – Jul 22
EggplantStart seeds indoorsMay 8 – Jun 6
EggplantTransplant outdoorsJun 21 – Jul 22
CucumbersSow outdoorsJun 21 – Jun 4
Summer squashSow outdoorsJun 7 – Jul 22
Winter squash & pumpkinsSow outdoorsJun 21 – Jul 22
Snap beansSow outdoorsJun 7 – Jun 27
Sweet cornSow outdoorsJun 7 – May 25
Watermelon & cantaloupeSow outdoorsJun 21 – Jul 22
OkraSow outdoorsJun 14 – Jul 7
PeasSow outdoors (spring)Apr 21 – Jun 6
PotatoesPlant outdoors (spring)Apr 21 – Jun 21
OnionsStart seeds indoors (spring)Mar 10 – Apr 6
OnionsTransplant outdoors (spring)May 8 – Jun 6
BroccoliStart seeds indoors (spring)Apr 3 – May 7
BroccoliTransplant outdoors (spring)May 8 – Jun 6
BroccoliStart seeds indoors (fall)May 15 – May 25
BroccoliTransplant outdoors (fall)Jun 14 – Jun 25
CabbageStart seeds indoors (spring)Mar 24 – Apr 21
CabbageTransplant outdoors (spring)Apr 21 – May 22
CabbageStart seeds indoors (fall)May 5 – Jun 4
CabbageTransplant outdoors (fall)Jun 4 – Jul 5
Leaf lettuceSow outdoors (spring)Apr 21 – Jul 7
Leaf lettuceSow outdoors (fall)Jun 4 – Jul 21
SpinachSow outdoors (spring)Apr 14 – May 28
SpinachSow outdoors (fall)Jun 21 – Jul 26
RadishesSow outdoors (spring)Apr 21 – Jun 11
RadishesSow outdoors (fall)Jun 4 – Aug 5
KaleSow outdoors (spring)May 8 – May 28
KaleSow outdoors (fall)May 28 – Jul 5
CarrotsSow outdoors (spring)May 22 – Jul 7
CarrotsSow outdoors (fall)May 5 – Jun 20
GarlicPlant outdoors (fall)Sep 4 – Oct 5

Where these dates come from

ZIP code 99006 is matched to the NOAA station Deer Park Ap, WA, 4.2 km away, at 2,191 ft elevation (72 ft higher than the ZIP code's center). Nearby stations for comparison:

StationElevationAvg last frostAvg first frost
Deer Park Ap, WA (used)2,191 ftMay 22Sep 14
Spokane Felts Fld, WA1,953 ftApr 26Oct 15
Spokane Wfo, WA2,392 ftMay 10Sep 26
Spokane Intl Ap, WA2,353 ftApr 26Oct 12

Frost dates near Deer Park

Frequently asked questions

When is the last frost in Deer Park, WA?
For ZIP code 99006, the average last spring frost (32°F) is May 22, based on NOAA 1991-2020 climate normals for the Deer Park Ap, WA weather station. There is a 1-in-10 chance of a frost after June 15.
When is the first frost in Deer Park, WA?
The average first fall frost (32°F) is September 14. There is a 1-in-10 chance of frost by August 28, so tender plants are at risk from that point on.
How long is the growing season in 99006?
In half of years, the frost-free season (between the last and first 32°F frost) is at least 112 days long.
Are these frost dates a forecast?
No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.