St. Onge weather by month
What a typical year looks like in St. Onge, South Dakota: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at SPEARFISH, 13 km from St. Onge; records cover 1893–2026.
The year at a glance
- Precipitation a year
- 21.4 in544 mm
- Snow a year
- 71 in179 cm
- Last spring freeze
- May 9
- First fall freeze
- Oct 5
- Heating degree days
- 7,217
- Cooling degree days
- 507
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −10°−23° (heating, 99%) and 98°37° (cooling, 1%).
Month by month
St. Onge in January
Highs average 36°2° and lows 16°−9°, with 0.6 in15 mm of precipitation and 8 in21 cm of snow in a typical January.
- Record high
- 79°26° (1921)
- Record low
- −32°−36° (1950)
- Heating degree days
- 1215
- Cooling degree days
- 0
St. Onge in February
Highs average 37°3° and lows 16°−9°, with 0.91 in23 mm of precipitation and 13 in32 cm of snow in a typical February.
- Record high
- 75°24° (1982)
- Record low
- −33°−36° (2021)
- Heating degree days
- 1075
- Cooling degree days
- 0
St. Onge in March
Highs average 46°8° and lows 24°−4°, with 1.2 in30 mm of precipitation and 12 in30 cm of snow in a typical March.
- Record high
- 82°28° (1910)
- Record low
- −27°−33° (2019)
- Heating degree days
- 930
- Cooling degree days
- 0
St. Onge in April
Highs average 55°13° and lows 32°0°, with 2.2 in57 mm of precipitation and 9 in22 cm of snow in a typical April.
- Record high
- 91°33° (1980)
- Record low
- −8°−22° (1920)
- Heating degree days
- 648
- Cooling degree days
- 1
St. Onge in May
Highs average 64°18° and lows 42°5°, with 3.7 in94 mm of precipitation and 2.3 in5.8 cm of snow in a typical May.
- Record high
- 96°36° (1969)
- Record low
- 11°−12° (1909)
- Heating degree days
- 380
- Cooling degree days
- 10
St. Onge in June
Highs average 75°24° and lows 51°11°, with 3.5 in89 mm of precipitation in a typical June.
- Record high
- 105°41° (1893)
- Record low
- 25°−4° (1920)
- Heating degree days
- 117
- Cooling degree days
- 66
St. Onge in July
Highs average 84°29° and lows 58°14°, with 2.4 in60 mm of precipitation in a typical July.
- Record high
- 110°43° (1936)
- Record low
- 33°1° (1906)
- Heating degree days
- 22
- Cooling degree days
- 196
St. Onge in August
Highs average 83°28° and lows 56°13°, with 1.9 in48 mm of precipitation in a typical August.
- Record high
- 104°40° (1900)
- Record low
- 32°0° (1906)
- Heating degree days
- 32
- Cooling degree days
- 172
St. Onge in September
Highs average 74°23° and lows 48°9°, with 1.6 in40 mm of precipitation and 0.1 in0.3 cm of snow in a typical September.
- Record high
- 105°41° (1978)
- Record low
- 15°−9° (1926)
- Heating degree days
- 184
- Cooling degree days
- 58
St. Onge in OctoberThis month
Highs average 58°15° and lows 35°2°, with 2 in52 mm of precipitation and 6 in14 cm of snow in a typical October.
- Record high
- 95°35° (1908)
- Record low
- −7°−22° (2020)
- Heating degree days
- 569
- Cooling degree days
- 4
St. Onge in November
Highs average 46°8° and lows 26°−4°, with 0.7 in18 mm of precipitation and 6 in16 cm of snow in a typical November.
- Record high
- 85°29° (1908)
- Record low
- −23°−31° (1959)
- Heating degree days
- 878
- Cooling degree days
- 0
St. Onge in December
Highs average 37°3° and lows 18°−8°, with 0.72 in18 mm of precipitation and 15 in38 cm of snow in a typical December.
- Record high
- 73°23° (1920)
- Record low
- −30°−34° (1916)
- Heating degree days
- 1167
- Cooling degree days
- 0