Frost Dates for Arrowrock Dam, ID

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 28
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 14
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 4
First Fall Frost October 8

Hard Freeze (28°F / -2°C)

Last Spring Hard Freeze April 6
First Fall Hard Freeze October 27
43.59°N, -115.92°W © OpenStreetMap

Growing Season

169 Days April 28 to October 14

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

Learn more

Temperature

20° 40° 60° 80° 100°
30°
High: 37°
Avg: 30°
Low: 22°
Jan
34°
High: 43°
Avg: 34°
Low: 25°
Feb
42°
High: 53°
Avg: 42°
Low: 32°
Mar
49°
High: 61°
Avg: 49°
Low: 37°
Apr
58°
High: 71°
Avg: 58°
Low: 44°
May
65°
High: 80°
Avg: 65°
Low: 50°
Jun
75°
High: 92°
Avg: 75°
Low: 59°
Jul
74°
High: 91°
Avg: 74°
Low: 57°
Aug
65°
High: 80°
Avg: 65°
Low: 49°
Sep
51°
High: 65°
Avg: 51°
Low: 38°
Oct
39°
High: 48°
Avg: 39°
Low: 30°
Nov
30°
High: 37°
Avg: 30°
Low: 24°
Dec
32°F
28°F
Avg High Avg Temp Avg Low Light Frost (32°F) Hard Frost (28°F)

Precipitation

0" 1" 2" 2.7"
2.4"
2.43"
Jan
2.0"
2.01"
Feb
2.7"
2.66"
Mar
2.5"
2.49"
Apr
2.5"
2.49"
May
2.1"
2.15"
Jun
0.1"
0.14"
Jul
0.0"
0.00"
Aug
1.3"
1.26"
Sep
2.0"
2.03"
Oct
2.1"
2.10"
Nov
2.2"
2.17"
Dec

Sunrise / Sunset

4a7a10a1p4p7p10pNoonJanFebMarAprMayJunJulAugSepOctNovDec9h10h12h13h15h15h15h14h12h11h9h9h
Jan: 7:27 AM – 4:33 PM · 9h 06m
Feb: 6:52 AM – 5:08 PM · 10h 16m
Mar: 6:11 AM – 5:49 PM · 11h 39m
Apr: 5:24 AM – 6:36 PM · 13h 13m
May: 4:44 AM – 7:16 PM · 14h 31m
Jun: 4:23 AM – 7:37 PM · 15h 14m
Jul: 4:32 AM – 7:28 PM · 14h 56m
Aug: 5:06 AM – 6:54 PM · 13h 48m
Sep: 5:52 AM – 6:08 PM · 12h 17m
Oct: 6:37 AM – 5:23 PM · 10h 46m
Nov: 7:17 AM – 4:43 PM · 9h 26m
Dec: 7:37 AM – 4:23 PM · 8h 46m
Daylight Longest: 15h 15m · Shortest: 8h 45m

Nearby Stations

Boise Lucky Peak Dam, ID April 30 - October 22 Boise Air Terminal, ID April 24 - October 21 Boise 7 N, IDMay 17 - October 12 Idaho City, ID June 17 - September 5 Emmett 2 E, ID April 30 - October 17 Nampa Sugar Factory, ID April 29 - October 13

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