Frost Dates for Three Forks, MT

Based on data from Trident weather station, 5 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 9
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 27
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 14
First Fall Frost September 22

Hard Freeze (28°F)

Last Spring Hard Freeze April 29
First Fall Hard Freeze October 6
45.89°N, -111.55°W © OpenStreetMap

Growing Season

141 Days May 9 to September 27

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 4b

Avg. annual minimum: −25 to −20°F (−32 to −29°C)

Learn more

Köppen Climate iThe 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

10° 30° 50° 70° 90°
24°
High: 33°F
Avg: 24°F
Low: 16°F
Jan
27°
High: 37°F
Avg: 27°F
Low: 18°F
Feb
37°
High: 48°F
Avg: 37°F
Low: 26°F
Mar
45°
High: 56°F
Avg: 45°F
Low: 33°F
Apr
54°
High: 66°F
Avg: 54°F
Low: 42°F
May
61°
High: 74°F
Avg: 61°F
Low: 49°F
Jun
69°
High: 85°F
Avg: 69°F
Low: 54°F
Jul
67°
High: 84°F
Avg: 67°F
Low: 51°F
Aug
58°
High: 73°F
Avg: 58°F
Low: 43°F
Sep
46°
High: 58°F
Avg: 46°F
Low: 33°F
Oct
33°
High: 42°F
Avg: 33°F
Low: 23°F
Nov
24°
High: 33°F
Avg: 24°F
Low: 15°F
Dec
32°F
28°F
Avg High Avg Temp Avg Low Light Frost (32°F) Hard Frost (28°F)

Precipitation

0" 1" 2" 3" 3.6"
1.6"
1.60"
Jan
1.3"
1.25"
Feb
1.9"
1.92"
Mar
2.6"
2.65"
Apr
3.1"
3.14"
May
3.6"
3.63"
Jun
3.4"
3.35"
Jul
2.7"
2.69"
Aug
3.0"
2.97"
Sep
2.5"
2.51"
Oct
1.6"
1.63"
Nov
1.8"
1.79"
Dec

Sunrise / Sunset

4a7a10a1p4p7p10pNoonJanFebMarAprMayJunJulAugSepOctNovDec9h10h11.5h13.5h14.5h15.5h15h14h12.5h10.5h9h8.5h
Jan: 7:35 AM – 4:25 PM · 8h 50m
Feb: 6:57 AM – 5:03 PM · 10h 07m
Mar: 6:12 AM – 5:48 PM · 11h 37m
Apr: 5:21 AM – 6:39 PM · 13h 19m
May: 4:38 AM – 7:22 PM · 14h 45m
Jun: 4:14 AM – 7:46 PM · 15h 32m
Jul: 4:24 AM – 7:36 PM · 15h 12m
Aug: 5:01 AM – 6:59 PM · 13h 58m
Sep: 5:51 AM – 6:09 PM · 12h 18m
Oct: 6:40 AM – 5:20 PM · 10h 39m
Nov: 7:24 AM – 4:36 PM · 9h 12m
Dec: 7:46 AM – 4:14 PM · 8h 28m
Daylight Longest: 15h 33m · Shortest: 8h 27m

Nearby Stations

Logan Landfill, MT May 26 - September 15 Bozeman Gallatin Fld, MT May 26 - September 16 Townsend 3se, MT May 19 - September 19 Bozeman 6 W Exp Farm, MT May 23 - September 23 Bozeman Montana State Univ, MT May 26 - September 22 Norris Madison Pwr House, MT April 30 - October 10

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