Frost Dates for Ice Harbor Dam, WA

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. April 7
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. October 22
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 April 17
First Fall Frost October 15

Hard Freeze (28°F / -2°C)

Last Spring Hard Freeze March 18
First Fall Hard Freeze November 4
46.24°N, -118.88°W © OpenStreetMap

Growing Season

198 Days April 7 to October 22

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 7b

Learn more

Temperature

20° 40° 60° 80°
35°
High: 42°
Avg: 35°
Low: 29°
Jan
39°
High: 48°
Avg: 39°
Low: 30°
Feb
46°
High: 58°
Avg: 46°
Low: 35°
Mar
53°
High: 65°
Avg: 53°
Low: 41°
Apr
61°
High: 74°
Avg: 61°
Low: 48°
May
67°
High: 80°
Avg: 67°
Low: 54°
Jun
75°
High: 89°
Avg: 75°
Low: 61°
Jul
74°
High: 89°
Avg: 74°
Low: 59°
Aug
66°
High: 80°
Avg: 66°
Low: 51°
Sep
54°
High: 66°
Avg: 54°
Low: 42°
Oct
43°
High: 51°
Avg: 43°
Low: 35°
Nov
36°
High: 42°
Avg: 36°
Low: 29°
Dec
32°F
28°F
Avg High Avg Temp Avg Low Light Frost (32°F) Hard Frost (28°F)

Precipitation

0" 1" 2" 2.4"
1.6"
1.55"
Jan
1.4"
1.40"
Feb
1.6"
1.55"
Mar
1.7"
1.69"
Apr
1.9"
1.92"
May
2.4"
2.39"
Jun
0.2"
0.22"
Jul
0.0"
0.00"
Aug
1.4"
1.40"
Sep
1.6"
1.55"
Oct
1.3"
1.27"
Nov
1.6"
1.55"
Dec

Sunrise / Sunset

4a7a10a1p4p7p10pNoonJanFebMarAprMayJunJulAugSepOctNovDec9h10h12h13h15h16h15h14h12h11h9h8h
Jan: 7:36 AM – 4:24 PM · 8h 48m
Feb: 6:57 AM – 5:03 PM · 10h 06m
Mar: 6:12 AM – 5:48 PM · 11h 36m
Apr: 5:20 AM – 6:40 PM · 13h 20m
May: 4:37 AM – 7:23 PM · 14h 47m
Jun: 4:13 AM – 7:47 PM · 15h 34m
Jul: 4:23 AM – 7:37 PM · 15h 15m
Aug: 5:01 AM – 6:59 PM · 13h 59m
Sep: 5:51 AM – 6:09 PM · 12h 19m
Oct: 6:41 AM – 5:19 PM · 10h 39m
Nov: 7:25 AM – 4:35 PM · 9h 10m
Dec: 7:47 AM – 4:13 PM · 8h 26m
Daylight Longest: 15h 36m · Shortest: 8h 25m

Nearby Stations

Kennewick, WA March 28 - October 30 Pasco Tri Cities AP, WA April 27 - October 11 Sagemoor, WAApril 30 - October 13 Eltopia 8 Wsw, WA April 21 - October 22 Richland, WAApril 6 - October 24 Whitman Mission, WA May 2 - October 1

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