Frost Dates for Mcnary Dam, WA

Elevation: 110 m

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 27
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 April 3
First Fall Frost October 29

Hard Freeze (28°F)

Last Spring Hard Freeze March 6
First Fall Hard Freeze November 18
45.94°N, 119.30°W © OpenStreetMap

Growing Season

222 Days March 27 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 8a

Avg. annual minimum: 10 to 15°F

Learn more

Köppen Climate

The Köppen climate classification system categorizes climates based on temperature and precipitation patterns.
BSk Cold Semi-Arid (Steppe)

Cool to cold with low rainfall and wide temperature swings. Common in the western Great Plains and central Asia. Short growing seasons benefit from season extension techniques.

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°39°31°
March56°46°36°
April64°53°42°
May73°61°49°
June80°67°55°
July89°75°62°
August88°75°61°
September78°66°54°
October64°54°44°
November51°43°36°
December42°36°30°

Precipitation

Precipitation table
Average monthly precipitation (inches)
MonthPrecipitation
January1.3
February1.4
March1.6
April1.5
May2.0
June1.6
July0.0
August0.0
September0.6
October1.7
November1.6
December1.6

Sunrise / Sunset

Daylight Longest: 15h 33m · Shortest: 8h 27m
Sunrise and sunset table
Sunrise, sunset, and daylight on the 15th of each month (local solar time)
Month Sunrise Sunset Daylight
January7:35 AM4:25 PM8h 50m
February6:57 AM5:03 PM10h 07m
March6:12 AM5:48 PM11h 37m
April5:21 AM6:39 PM13h 19m
May4:38 AM7:22 PM14h 45m
June4:14 AM7:46 PM15h 32m
July4:24 AM7:36 PM15h 12m
August5:01 AM6:59 PM13h 57m
September5:51 AM6:09 PM12h 18m
October6:40 AM5:20 PM10h 39m
November7:24 AM4:36 PM9h 12m
December7:46 AM4:14 PM8h 28m

Nearby Stations

Mcnary Dam #2, OR March 30 - November 4 Hermiston 2 Nw, OR April 27 - October 7 Hermiston Muni AP, OR April 26 - October 10 Boardman, ORApril 14 - October 21 Kennewick, WA March 28 - October 30 Pasco Tri Cities AP, WA April 27 - October 11

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