Custer weather by month
What a typical year looks like in Custer, South Dakota: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Custer, 1 km from Custer; records cover 1942–2026.
The year at a glance
- Precipitation a year
- 20.7 in525 mm
- Snow a year
- 58 in147 cm
- Last spring freeze
- May 23
- First fall freeze
- Sep 20
- Heating degree days
- 7,585
- Cooling degree days
- 308
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −9°−23° (heating, 99%) and 90°32° (cooling, 1%).
Month by month
Custer in January
Highs average 37°3° and lows 16°−9°, with 0.36 in9.1 mm of precipitation and 7 in17 cm of snow in a typical January.
- Record high
- 68°20° (1981)
- Record low
- −43°−42° (1963)
- Heating degree days
- 1189
- Cooling degree days
- 0
Custer in February
Highs average 37°3° and lows 16°−9°, with 0.7 in18 mm of precipitation and 11 in27 cm of snow in a typical February.
- Record high
- 68°20° (1958)
- Record low
- −34°−37° (1962)
- Heating degree days
- 1074
- Cooling degree days
- 0
Custer in March
Highs average 46°8° and lows 24°−4°, with 0.92 in23 mm of precipitation and 11 in27 cm of snow in a typical March.
- Record high
- 77°25° (2026)
- Record low
- −30°−34° (1956)
- Heating degree days
- 936
- Cooling degree days
- 0
Custer in April
Highs average 51°11° and lows 31°−1°, with 2.2 in57 mm of precipitation and 11 in28 cm of snow in a typical April.
- Record high
- 84°29° (1989)
- Record low
- −8°−22° (1975)
- Heating degree days
- 723
- Cooling degree days
- 0
Custer in May
Highs average 61°16° and lows 41°5°, with 3.5 in90 mm of precipitation and 2.1 in5.3 cm of snow in a typical May.
- Record high
- 90°32° (1969)
- Record low
- 5°−15° (1954)
- Heating degree days
- 442
- Cooling degree days
- 4
Custer in June
Highs average 72°22° and lows 50°10°, with 3.4 in87 mm of precipitation in a typical June.
- Record high
- 97°36° (1954)
- Record low
- 19°−7° (1951)
- Heating degree days
- 159
- Cooling degree days
- 38
Custer in July
Highs average 80°27° and lows 56°13°, with 3.2 in80 mm of precipitation in a typical July.
- Record high
- 100°38° (1954)
- Record low
- 25°−4° (2025)
- Heating degree days
- 41
- Cooling degree days
- 134
Custer in August
Highs average 79°26° and lows 55°13°, with 2.4 in62 mm of precipitation in a typical August.
- Record high
- 96°36° (1975)
- Record low
- 22°−6° (1966)
- Heating degree days
- 53
- Cooling degree days
- 104
Custer in September
Highs average 71°22° and lows 46°8°, with 1.5 in39 mm of precipitation and 0.8 in2 cm of snow in a typical September.
- Record high
- 97°36° (1971)
- Record low
- 8°−13° (1961)
- Heating degree days
- 225
- Cooling degree days
- 28
Custer in OctoberThis month
Highs average 56°13° and lows 34°1°, with 1.5 in37 mm of precipitation and 4 in10 cm of snow in a typical October.
- Record high
- 85°29° (1963)
- Record low
- −10°−23° (2020)
- Heating degree days
- 630
- Cooling degree days
- 0
Custer in November
Highs average 45°7° and lows 24°−5°, with 0.55 in14 mm of precipitation and 7 in17 cm of snow in a typical November.
- Record high
- 76°24° (1975)
- Record low
- −25°−32° (1952)
- Heating degree days
- 921
- Cooling degree days
- 0
Custer in December
Highs average 37°3° and lows 17°−9°, with 0.36 in9.1 mm of precipitation and 5 in14 cm of snow in a typical December.
- Record high
- 68°20° (1979)
- Record low
- −37°−38° (1964)
- Heating degree days
- 1192
- Cooling degree days
- 0