Frost Dates for Colfax, WA

Based on data from Pullman 2 Nw weather station, 12 miles away

Frost Dates

Last Spring Frost (50%) iA 50% chance that the last spring frost has already passed by this date. Most gardeners use this as their primary planting guide. May 6
First Fall Frost (50%) iA 50% chance that the first fall frost has occurred by this date. Plan to harvest or protect tender plants before this date. September 29
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

30% Probability iOnly 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 May 13
First Fall Frost September 22

Hard Freeze (28°F)

Last Spring Hard Freeze April 19
First Fall Hard Freeze October 12
46.88°N, -117.36°W © OpenStreetMap

Growing Season

146 Days May 6 to September 29

USDA Hardiness Zone iHardiness 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 6b

Avg. annual minimum: −5 to 0°F (−21 to −18°C)

Learn more

Köppen Climate iThe Köppen climate classification system categorizes climates based on temperature and precipitation patterns.

Dsb Warm-Summer Continental (Dry Summer)

Warm, dry summers and cold, snowy winters. Common in mountain regions. Moderate growing season with irrigation needs in summer.

Köppen climate map

Temperature

20° 40° 60° 80°
32°
High: 38°F
Avg: 32°F
Low: 26°F
Jan
35°
High: 42°F
Avg: 35°F
Low: 27°F
Feb
40°
High: 50°F
Avg: 40°F
Low: 31°F
Mar
46°
High: 57°F
Avg: 46°F
Low: 35°F
Apr
54°
High: 66°F
Avg: 54°F
Low: 42°F
May
60°
High: 73°F
Avg: 60°F
Low: 46°F
Jun
67°
High: 84°F
Avg: 67°F
Low: 50°F
Jul
68°
High: 85°F
Avg: 68°F
Low: 50°F
Aug
60°
High: 76°F
Avg: 60°F
Low: 44°F
Sep
49°
High: 61°F
Avg: 49°F
Low: 36°F
Oct
38°
High: 46°F
Avg: 38°F
Low: 31°F
Nov
31°
High: 37°F
Avg: 31°F
Low: 25°F
Dec
32°F
28°F
Avg High Avg Temp Avg Low Light Frost (32°F) Hard Frost (28°F)

Precipitation

0" 2" 4" 4.2"
3.9"
3.89"
Jan
3.3"
3.30"
Feb
3.7"
3.74"
Mar
3.4"
3.37"
Apr
3.6"
3.61"
May
2.9"
2.94"
Jun
2.0"
2.04"
Jul
2.0"
2.05"
Aug
2.8"
2.75"
Sep
3.6"
3.64"
Oct
4.0"
3.96"
Nov
4.2"
4.19"
Dec

Sunrise / Sunset

4a7a10a1p4p7p10pNoonJanFebMarAprMayJunJulAugSepOctNovDec8.5h10h11.5h13.5h15h15.5h15.5h14h12.5h10.5h9h8.5h
Jan: 7:38 AM – 4:22 PM · 8h 44m
Feb: 6:58 AM – 5:02 PM · 10h 04m
Mar: 6:12 AM – 5:48 PM · 11h 36m
Apr: 5:19 AM – 6:41 PM · 13h 21m
May: 4:35 AM – 7:25 PM · 14h 50m
Jun: 4:11 AM – 7:49 PM · 15h 38m
Jul: 4:21 AM – 7:39 PM · 15h 18m
Aug: 4:60 AM – 7:00 PM · 14h 01m
Sep: 5:51 AM – 6:09 PM · 12h 19m
Oct: 6:41 AM – 5:19 PM · 10h 37m
Nov: 7:27 AM – 4:33 PM · 9h 07m
Dec: 7:49 AM – 4:11 PM · 8h 22m
Daylight Longest: 15h 40m · Shortest: 8h 20m

Nearby Stations

Pullman Moscow Rgnl AP, WA April 29 - October 2 Moscow U Of I, ID Potlatch 3 Nne, ID May 15 - September 21 Pomeroy, WAMay 2 - October 4 Lewiston Nez Perce Co AP, ID April 6 - October 26 St John, WAApril 29 - October 4

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