Frost Dates for Blackhawk, SD

Based on data from Rapid City 4nw weather station, 2 miles away

Elevation: 3494 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 10
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. October 5

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 15
First Fall Frost September 29

Hard Freeze (28°F)

Last Spring Hard Freeze April 28
First Fall Hard Freeze October 15
44.15°N, 103.31°W © OpenStreetMap

Growing Season

148 Days May 10 to October 5

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.
Dwa Hot-Summer Continental (Dry Winter)

Hot, wet summers and cold, dry winters. Monsoon influence brings most rain in summer. Good for warm-season crops during the rainy season; winters are harsh but dry.

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
January37°25°13°
February38°26°15°
March47°35°23°
April54°43°31°
May64°53°42°
June75°64°52°
July84°71°58°
August83°70°56°
September74°60°47°
October59°47°35°
November47°35°24°
December39°27°15°

Precipitation

Precipitation table
Average monthly precipitation (inches)
MonthPrecipitation
January0.8
February2.3
March3.8
April4.9
May6.3
June5.4
July5.4
August4.7
September4.8
October4.7
November1.6
December0.0

Sunrise / Sunset

Daylight Mountain Time (MT) Longest: 15h 19m · Shortest: 8h 41m
Sunrise and sunset table
Sunrise, sunset, and daylight on the 15th of each month (Mountain Time (MT))
Month Sunrise Sunset Daylight
January7:31 AM4:34 PM9h 03m
February7:01 AM5:15 PM10h 14m
March7:14 AM6:52 PM11h 38m
April6:16 AM7:30 PM13h 14m
May5:32 AM8:06 PM14h 34m
June5:15 AM8:32 PM15h 18m
July5:29 AM8:29 PM14h 60m
August6:02 AM7:52 PM13h 50m
September6:39 AM6:56 PM12h 17m
October7:16 AM6:01 PM10h 44m
November6:57 AM4:20 PM9h 23m
December7:28 AM4:10 PM8h 42m

Nearby Stations

Rapid City Wfo, SD May 3 - October 8 Johnson Siding, SD May 20 - September 25 Pactola Dam, SD May 28 - September 18 Rapid City Rgnl AP, SD May 12 - October 1 Hereford 12 Sw, SD May 8 - October 3 Hill City, SD June 1 - September 10

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