Frost Dates for Fort Belknap Agency, MT

Based on data from Ft Belknap 2 Sw weather station, 1 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 16
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 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 May 21
First Fall Frost September 18

Hard Freeze (28°F)

Last Spring Hard Freeze May 6
First Fall Hard Freeze September 30
48.48°N, -108.77°W © OpenStreetMap

Growing Season

129 Days May 16 to September 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 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

0° 30° 60° 90°
17°
High: 27°F
Avg: 17°F
Low: 6°F
Jan
20°
High: 32°F
Avg: 20°F
Low: 8°F
Feb
30°
High: 42°F
Avg: 30°F
Low: 18°F
Mar
42°
High: 56°F
Avg: 42°F
Low: 29°F
Apr
53°
High: 66°F
Avg: 53°F
Low: 40°F
May
62°
High: 74°F
Avg: 62°F
Low: 49°F
Jun
69°
High: 84°F
Avg: 69°F
Low: 54°F
Jul
68°
High: 84°F
Avg: 68°F
Low: 52°F
Aug
57°
High: 72°F
Avg: 57°F
Low: 42°F
Sep
43°
High: 57°F
Avg: 43°F
Low: 30°F
Oct
30°
High: 42°F
Avg: 30°F
Low: 19°F
Nov
20°
High: 31°F
Avg: 20°F
Low: 9°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" 3.8"
1.6"
1.55"
Jan
1.4"
1.45"
Feb
1.7"
1.72"
Mar
2.0"
2.01"
Apr
3.5"
3.48"
May
3.8"
3.77"
Jun
3.4"
3.41"
Jul
2.9"
2.91"
Aug
2.7"
2.72"
Sep
2.6"
2.57"
Oct
1.8"
1.79"
Nov
1.6"
1.55"
Dec

Sunrise / Sunset

4a7a10a1p4p7p10pNoonJanFebMarAprMayJunJulAugSepOctNovDec8.5h10h11.5h13.5h15h16h15.5h14h12.5h10.5h9h8h
Jan: 7:44 AM – 4:16 PM · 8h 31m
Feb: 7:02 AM – 4:58 PM · 9h 56m
Mar: 6:13 AM – 5:47 PM · 11h 35m
Apr: 5:17 AM – 6:43 PM · 13h 26m
May: 4:30 AM – 7:30 PM · 15h 01m
Jun: 4:04 AM – 7:56 PM · 15h 53m
Jul: 4:14 AM – 7:46 PM · 15h 31m
Aug: 4:56 AM – 7:04 PM · 14h 09m
Sep: 5:50 AM – 6:10 PM · 12h 20m
Oct: 6:44 AM – 5:16 PM · 10h 32m
Nov: 7:32 AM – 4:28 PM · 8h 55m
Dec: 7:57 AM – 4:03 PM · 8h 07m
Daylight Longest: 15h 55m · Shortest: 8h 06m

Nearby Stations

Harlem, MTMay 16 - September 21 Harlem 20s, MT May 24 - September 22 Chinook, MTMay 14 - September 23 Chinook 35se, MT May 23 - September 23 Zortman, MTMay 18 - September 23 Turner 11n, MT May 19 - September 21

Plan Your Garden with Planter

Now that you know your frost dates, use Planter to plan your veggie garden! Planter is an easy drag-and-drop garden planner with personalized planting schedules.

Try Planter For Free

Available everywhere: iOS, Android, web, and more!

Planter app garden planner preview