Frost Dates for Rock Springs, WY

Based on data from Rock Springs Fire Dept weather station, 2 miles away

Elevation: 6388 ft

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 24
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 24

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 31
First Fall Frost September 18

Hard Freeze (28°F)

Last Spring Hard Freeze May 9
First Fall Hard Freeze October 3
41.59°N, 109.20°W © OpenStreetMap

Growing Season

123 Days May 24 to September 24

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 5a

Avg. annual minimum: −20 to −15°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
January35°24°12°
February38°27°15°
March49°36°23°
April57°43°30°
May67°52°37°
June79°62°45°
July86°69°53°
August84°68°51°
September75°58°41°
October61°46°31°
November45°33°21°
December33°23°12°

Precipitation

Precipitation table
Average monthly precipitation (inches)
MonthPrecipitation
January2.2
February1.7
March2.3
April2.9
May2.9
June2.5
July2.0
August2.5
September2.9
October3.0
November2.6
December2.2

Sunrise / Sunset

Daylight Mountain Time (MT) Longest: 15h 01m · Shortest: 8h 59m
Sunrise and sunset table
Sunrise, sunset, and daylight on the 15th of each month (Mountain Time (MT))
Month Sunrise Sunset Daylight
January7:47 AM5:05 PM9h 18m
February7:20 AM5:43 PM10h 23m
March7:37 AM7:17 PM11h 40m
April6:43 AM7:51 PM13h 08m
May6:03 AM8:23 PM14h 21m
June5:47 AM8:47 PM14h 60m
July6:01 AM8:44 PM14h 44m
August6:31 AM8:11 PM13h 41m
September7:04 AM7:19 PM12h 16m
October7:37 AM6:28 PM10h 51m
November7:14 AM4:50 PM9h 36m
December7:43 AM4:43 PM8h 60m

Nearby Stations

Rock Springs AP, WY May 22 - September 28 Green Rvr, WY May 24 - September 22 Buckboard Marina, WY May 24 - September 23 Bitter Creek 4 Ne, WY June 1 - September 16 Farson 2nne, WY Flaming Gorge, UT May 26 - September 23

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