Hecla weather by month
What a typical year looks like in Hecla, South Dakota: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Columbia 8 N, 21 km from Hecla; records cover 1949–2026.
The year at a glance
- Precipitation a year
- 22.5 in570 mm
- Snow a year
- 38 in96 cm
- Last spring freeze
- May 12
- First fall freeze
- Sep 30
- Heating degree days
- 8,588
- Cooling degree days
- 556
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −21°−29° (heating, 99%) and 92°33° (cooling, 1%).
Month by month
Hecla in January
Highs average 22°−6° and lows 0°−18°, with 0.47 in12 mm of precipitation and 8 in20 cm of snow in a typical January.
- Record high
- 60°16° (1981)
- Record low
- −39° (2009)
- Heating degree days
- 1675
- Cooling degree days
- 0
Hecla in February
Highs average 26°−3° and lows 5°−15°, with 0.44 in11 mm of precipitation and 7 in17 cm of snow in a typical February.
- Record high
- 68°20° (1958)
- Record low
- −45°−43° (1994)
- Heating degree days
- 1387
- Cooling degree days
- 0
Hecla in March
Highs average 39°4° and lows 18°−8°, with 0.87 in22 mm of precipitation and 6 in15 cm of snow in a typical March.
- Record high
- 83°28° (1963)
- Record low
- −28°−33° (1962)
- Heating degree days
- 1132
- Cooling degree days
- 0
Hecla in April
Highs average 55°13° and lows 31°0°, with 1.8 in45 mm of precipitation and 4 in9 cm of snow in a typical April.
- Record high
- 95°35° (1962)
- Record low
- −9°−23° (1975)
- Heating degree days
- 656
- Cooling degree days
- 0
Hecla in May
Highs average 68°20° and lows 45°7°, with 3.4 in87 mm of precipitation in a typical May.
- Record high
- 101°38° (1959)
- Record low
- 18°−8° (1961)
- Heating degree days
- 287
- Cooling degree days
- 23
Hecla in June
Highs average 78°25° and lows 56°13°, with 3.6 in91 mm of precipitation in a typical June.
- Record high
- 106°41° (1988)
- Record low
- 33°1° (1966)
- Heating degree days
- 61
- Cooling degree days
- 113
Hecla in July
Highs average 83°28° and lows 60°16°, with 3.6 in92 mm of precipitation in a typical July.
- Record high
- 108°42° (1966)
- Record low
- 38°3° (1971)
- Heating degree days
- 15
- Cooling degree days
- 216
Hecla in August
Highs average 81°27° and lows 57°14°, with 2.6 in67 mm of precipitation in a typical August.
- Record high
- 108°42° (1965)
- Record low
- 34°1° (1968)
- Heating degree days
- 30
- Cooling degree days
- 159
Hecla in September
Highs average 73°23° and lows 47°8°, with 2.4 in60 mm of precipitation in a typical September.
- Record high
- 99°37° (1984)
- Record low
- 15°−9° (1965)
- Heating degree days
- 196
- Cooling degree days
- 43
Hecla in OctoberThis month
Highs average 58°14° and lows 33°1°, with 2.1 in54 mm of precipitation and 0.7 in1.8 cm of snow in a typical October.
- Record high
- 97°36° (1990)
- Record low
- −1°−18° (2020)
- Heating degree days
- 614
- Cooling degree days
- 2
Hecla in November
Highs average 41°5° and lows 19°−7°, with 0.68 in17 mm of precipitation and 6 in14 cm of snow in a typical November.
- Record high
- 79°26° (2006)
- Record low
- −26°−32° (1985)
- Heating degree days
- 1050
- Cooling degree days
- 0
Hecla in December
Highs average 27°−3° and lows 7°−14°, with 0.5 in13 mm of precipitation and 7 in18 cm of snow in a typical December.
- Record high
- 65°18° (1962)
- Record low
- −38°−39° (1967)
- Heating degree days
- 1485
- Cooling degree days
- 0