Frost Dates for Dillon, MT

Based on data from Dillon U Of Montana Western weather station, 0 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. June 5
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 13
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 June 13
First Fall Frost September 7

Hard Freeze (28°F)

Last Spring Hard Freeze May 16
First Fall Hard Freeze September 25
45.22°N, -112.64°W © OpenStreetMap

Growing Season

100 Days June 5 to September 13

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 5a

Avg. annual minimum: −20 to −15°F (−29 to −26°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: 15°F
Jan
26°
High: 37°F
Avg: 26°F
Low: 16°F
Feb
34°
High: 46°F
Avg: 34°F
Low: 23°F
Mar
41°
High: 54°F
Avg: 41°F
Low: 28°F
Apr
50°
High: 64°F
Avg: 50°F
Low: 36°F
May
58°
High: 73°F
Avg: 58°F
Low: 42°F
Jun
65°
High: 83°F
Avg: 65°F
Low: 48°F
Jul
63°
High: 81°F
Avg: 63°F
Low: 46°F
Aug
55°
High: 71°F
Avg: 55°F
Low: 39°F
Sep
43°
High: 56°F
Avg: 43°F
Low: 30°F
Oct
31°
High: 41°F
Avg: 31°F
Low: 21°F
Nov
22°
High: 32°F
Avg: 22°F
Low: 13°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" 3.0"
1.0"
1.04"
Jan
1.1"
1.09"
Feb
1.8"
1.78"
Mar
2.3"
2.33"
Apr
3.0"
2.97"
May
3.0"
3.03"
Jun
2.3"
2.34"
Jul
2.4"
2.41"
Aug
2.7"
2.70"
Sep
2.0"
1.96"
Oct
1.4"
1.38"
Nov
1.3"
1.34"
Dec

Sunrise / Sunset

4a7a10a1p4p7p10pNoonJanFebMarAprMayJunJulAugSepOctNovDec9h10h11.5h13.5h14.5h15.5h15h14h12.5h10.5h9.5h8.5h
Jan: 7:32 AM – 4:28 PM · 8h 55m
Feb: 6:55 AM – 5:05 PM · 10h 10m
Mar: 6:11 AM – 5:49 PM · 11h 37m
Apr: 5:22 AM – 6:38 PM · 13h 17m
May: 4:40 AM – 7:20 PM · 14h 40m
Jun: 4:17 AM – 7:43 PM · 15h 26m
Jul: 4:26 AM – 7:34 PM · 15h 07m
Aug: 5:03 AM – 6:57 PM · 13h 54m
Sep: 5:51 AM – 6:09 PM · 12h 18m
Oct: 6:39 AM – 5:21 PM · 10h 42m
Nov: 7:22 AM – 4:38 PM · 9h 16m
Dec: 7:43 AM – 4:17 PM · 8h 34m
Daylight Longest: 15h 27m · Shortest: 8h 33m

Nearby Stations

Dillon AP, MT June 2 - September 13 Dillon 18 Wsw, MT Glen 4 N, MT Twin Bridges, MT June 8 - September 2 Alder 19s, MT Laurin 2ne, MT May 24 - September 22

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