Frost Dates for Mattawa, WA

Based on data from Priest Rapids Dam weather station, 6 miles away

Elevation: 768 ft

Frost Dates

Last Spring Frost (50%) A 50% chance that the last spring frost has already passed by this date. Most gardeners use this as their primary planting guide. March 24
First Fall Frost (50%) A 50% chance that the first fall frost has occurred by this date. Plan to harvest or protect tender plants before this date. November 4

30% Probability

Only a 30% chance of frost remaining by this date. Use these dates for a safer planting window, especially for tender plants sensitive to cold.
Last Spring Frost March 31
First Fall Frost October 30

Hard Freeze (28°F)

Last Spring Hard Freeze March 5
First Fall Hard Freeze November 16
46.74°N, 119.90°W © OpenStreetMap

Growing Season

225 Days March 24 to November 4

USDA Hardiness Zone

Hardiness zones indicate which perennial plants can survive winter in your area. For annual vegetables, frost dates and growing season length matter more than hardiness zone.
Zone 7b

Avg. annual minimum: 5 to 10°F

Learn more

Köppen Climate

The Köppen climate classification system categorizes climates based on temperature and precipitation patterns.
BWk Cold Desert

Dry with hot summers and cold winters. Rainfall is minimal year-round. Short growing seasons and large temperature swings require careful timing. Cold-hardy, drought-tolerant plants are best suited.

Köppen climate map

Temperature

Avg High Avg Temp Avg Low Light Frost (32°F) Hard Frost (28°F)
Temperature table
Average monthly temperatures (°F)
Month Avg High Avg Temp Avg Low
January41°35°30°
February47°40°32°
March57°47°38°
April65°55°45°
May75°64°53°
June82°71°60°
July92°79°67°
August90°78°66°
September80°69°58°
October65°56°46°
November50°43°36°
December41°35°30°

Precipitation

Precipitation table
Average monthly precipitation (inches)
MonthPrecipitation
January1.6
February1.4
March1.6
April1.5
May1.8
June1.7
July0.0
August0.0
September0.3
October1.6
November1.5
December1.8

Sunrise / Sunset

Daylight Pacific Time (PT) Longest: 15h 39m · Shortest: 8h 21m
Sunrise and sunset table
Sunrise, sunset, and daylight on the 15th of each month (Pacific Time (PT))
Month Sunrise Sunset Daylight
January7:46 AM4:32 PM8h 45m
February7:12 AM5:16 PM10h 04m
March7:21 AM6:57 PM11h 36m
April6:19 AM7:40 PM13h 21m
May5:31 AM8:20 PM14h 49m
June5:11 AM8:48 PM15h 37m
July5:26 AM8:44 PM15h 17m
August6:04 AM8:04 PM14h 00m
September6:45 AM7:04 PM12h 19m
October7:26 AM6:03 PM10h 37m
November7:11 AM4:18 PM9h 07m
December7:44 AM4:07 PM8h 22m

Nearby Stations

Moxee City 10 E, WA May 4 - October 10 Smyrna, WAApril 23 - October 12 Sunnyside #2, WA April 30 - October 8 Sunnyside, WAMay 1 - October 6 Selah 2 Ne, WAMay 5 - October 4 Wapato, WAApril 21 - October 15

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