Onalaska weather by month
What a typical year looks like in Onalaska, Washington: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Mayfield Power Plant, 12 km from Onalaska; records cover 1980–2026.
The year at a glance
- Precipitation a year
- 58.7 in1492 mm
- Snow a year
- 3 in9 cm
- Last spring freeze
- Apr 15
- First fall freeze
- Nov 2
- Heating degree days
- 5,085
- Cooling degree days
- 238
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are 21°−6° (heating, 99%) and 99°37° (cooling, 1%).
Month by month
Onalaska in January
Highs average 45°7° and lows 33°1°, with 8.1 in205 mm of precipitation and 1.1 in2.8 cm of snow in a typical January.
- Record high
- 62°17° (2018)
- Record low
- 15°−9° (2024)
- Heating degree days
- 804
- Cooling degree days
- 0
Onalaska in February
Highs average 49°10° and lows 34°1°, with 5.8 in147 mm of precipitation and 1.3 in3.3 cm of snow in a typical February.
- Record high
- 72°22° (2025)
- Record low
- 14°−10° (2019)
- Heating degree days
- 662
- Cooling degree days
- 0
Onalaska in March
Highs average 54°12° and lows 35°2°, with 6.3 in160 mm of precipitation in a typical March.
- Record high
- 84°29° (2019)
- Record low
- 20°−7° (2019)
- Heating degree days
- 631
- Cooling degree days
- 0
Onalaska in April
Highs average 60°16° and lows 39°4°, with 5.5 in138 mm of precipitation in a typical April.
- Record high
- 92°33° (2016)
- Record low
- 26°−3° (2008)
- Heating degree days
- 471
- Cooling degree days
- 2
Onalaska in May
Highs average 69°21° and lows 43°6°, with 3.8 in97 mm of precipitation in a typical May.
- Record high
- 96°36° (2020)
- Record low
- 30°−1° (2024)
- Heating degree days
- 284
- Cooling degree days
- 10
Onalaska in June
Highs average 72°22° and lows 48°9°, with 2.7 in68 mm of precipitation in a typical June.
- Record high
- 118°48° (2021)
- Record low
- 40°4° (1980)
- Heating degree days
- 175
- Cooling degree days
- 26
Onalaska in July
Highs average 81°27° and lows 51°11°, with 0.91 in23 mm of precipitation in a typical July.
- Record high
- 106°41° (2006)
- Record low
- 40°4° (2011)
- Heating degree days
- 49
- Cooling degree days
- 88
Onalaska in August
Highs average 81°27° and lows 52°11°, with 1.3 in33 mm of precipitation in a typical August.
- Record high
- 112°44° (2023)
- Record low
- 40°4° (2006)
- Heating degree days
- 43
- Cooling degree days
- 86
Onalaska in September
Highs average 74°24° and lows 48°9°, with 2.5 in62 mm of precipitation in a typical September.
- Record high
- 103°39° (2017)
- Record low
- 34°1° (2014)
- Heating degree days
- 139
- Cooling degree days
- 25
Onalaska in OctoberThis month
Highs average 62°17° and lows 43°6°, with 5.4 in137 mm of precipitation in a typical October.
- Record high
- 86°30° (2022)
- Record low
- 26°−3° (2006)
- Heating degree days
- 398
- Cooling degree days
- 1
Onalaska in November
Highs average 51°11° and lows 38°3°, with 8.4 in214 mm of precipitation in a typical November.
- Record high
- 74°23° (2016)
- Record low
- 12°−11° (2010)
- Heating degree days
- 622
- Cooling degree days
- 0
Onalaska in December
Highs average 44°7° and lows 34°1°, with 8.1 in207 mm of precipitation and 1 in2.5 cm of snow in a typical December.
- Record high
- 64°18° (2014)
- Record low
- 12°−11° (2013)
- Heating degree days
- 807
- Cooling degree days
- 0