Frost Dates for Cascade 5 S, MT

Elevation: 1024 m

Frost Dates

Last Spring Frost (50%) A 50% chance that the last spring frost has already passed by this date. Most gardeners use this as their primary planting guide. May 21
First Fall Frost (50%) A 50% chance that the first fall frost has occurred by this date. Plan to harvest or protect tender plants before this date. September 19

30% Probability

Only 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 27
First Fall Frost September 12

Hard Freeze (28°F)

Last Spring Hard Freeze May 7
First Fall Hard Freeze October 1
47.22°N, 111.71°W © OpenStreetMap

Growing Season

121 Days May 21 to September 19

USDA Hardiness Zone

Hardiness 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 3b

Avg. annual minimum: −35 to −30°F

Learn more

Köppen Climate

The 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

Avg High Avg Temp Avg Low Light Frost (32°F) Hard Frost (28°F)
Temperature table
Average monthly temperatures (°F)
Month Avg High Avg Temp Avg Low
January39°29°19°
February40°29°19°
March49°37°25°
April58°45°33°
May67°54°40°
June75°61°47°
July86°69°52°
August85°68°50°
September74°59°44°
October60°48°36°
November47°37°27°
December38°29°20°

Precipitation

Precipitation table
Average monthly precipitation (inches)
MonthPrecipitation
January2.4
February2.0
March2.6
April3.4
May4.4
June4.3
July3.4
August3.9
September5.0
October3.9
November2.8
December2.5

Sunrise / Sunset

Daylight Longest: 15h 44m · Shortest: 8h 16m
Sunrise and sunset table
Sunrise, sunset, and daylight on the 15th of each month (local solar time)
Month Sunrise Sunset Daylight
January7:40 AM4:20 PM8h 41m
February6:59 AM5:01 PM10h 02m
March6:12 AM5:48 PM11h 36m
April5:19 AM6:41 PM13h 23m
May4:34 AM7:26 PM14h 53m
June4:09 AM7:51 PM15h 42m
July4:19 AM7:41 PM15h 22m
August4:59 AM7:01 PM14h 03m
September5:50 AM6:10 PM12h 19m
October6:42 AM5:18 PM10h 36m
November7:28 AM4:32 PM9h 04m
December7:51 AM4:09 PM8h 18m

Nearby Stations

Adel, MTJune 4 - September 12 Cascade 20 Sse, MT Sun Rvr 4 S, MT June 2 - September 10 Holter Dam, MT May 19 - September 24 Great Falls Wfo, MT May 12 - September 28 Great Falls Intl AP, MT May 19 - September 24

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