Hillsboro weather by month
What a typical year looks like in Hillsboro, Wisconsin: average highs and lows, rain and snow, and the warmest and coldest days on record. Normals are the 1991–2020 averages at Hillsboro 2sw, 4 km from Hillsboro; records cover 2013–2026.
The year at a glance
- Precipitation a year
- 36.2 in920 mm
- Snow a year
- Rare
- Last spring freeze
- May 13
- First fall freeze
- Oct 2
- Heating degree days
- 8,112
- Cooling degree days
- 352
Freeze dates are medians (half of years earlier, half later). Degree days use a 65°F base; HVAC design temperatures here are −20°−29° (heating, 99%) and 89°32° (cooling, 1%).
Month by month
Hillsboro in January
Highs average 25°−4° and lows 6°−15°, with 1.2 in29 mm of precipitation in a typical January.
- Record high
- 56°13° (2025)
- Record low
- −40° (2019)
- Heating degree days
- 1548
- Cooling degree days
- 0
Hillsboro in February
Highs average 29°−2° and lows 8°−13°, with 1.1 in27 mm of precipitation in a typical February.
- Record high
- 69°21° (2024)
- Record low
- −39° (2019)
- Heating degree days
- 1302
- Cooling degree days
- 0
Hillsboro in March
Highs average 41°5° and lows 20°−7°, with 1.9 in49 mm of precipitation in a typical March.
- Record high
- 81°27° (2025)
- Record low
- −23°−31° (2014)
- Heating degree days
- 1074
- Cooling degree days
- 0
Hillsboro in April
Highs average 55°13° and lows 32°0°, with 3.7 in95 mm of precipitation in a typical April.
- Record high
- 84°29° (2023)
- Record low
- 3°−16° (2018)
- Heating degree days
- 654
- Cooling degree days
- 0
Hillsboro in May
Highs average 66°19° and lows 44°6°, with 4.4 in110 mm of precipitation in a typical May.
- Record high
- 94°34° (2018)
- Record low
- 20°−7° (2020)
- Heating degree days
- 323
- Cooling degree days
- 10
Hillsboro in June
Highs average 76°25° and lows 54°12°, with 5 in128 mm of precipitation in a typical June.
- Record high
- 94°34° (2022)
- Record low
- 31°−1° (2023)
- Heating degree days
- 70
- Cooling degree days
- 73
Hillsboro in July
Highs average 80°27° and lows 57°14°, with 4.4 in112 mm of precipitation in a typical July.
- Record high
- 94°34° (2026)
- Record low
- 41°5° (2023)
- Heating degree days
- 19
- Cooling degree days
- 140
Hillsboro in August
Highs average 78°26° and lows 55°13°, with 4.4 in112 mm of precipitation in a typical August.
- Record high
- 98°37° (2023)
- Record low
- 36°2° (2023)
- Heating degree days
- 52
- Cooling degree days
- 101
Hillsboro in September
Highs average 71°22° and lows 46°8°, with 3.8 in97 mm of precipitation in a typical September.
- Record high
- 95°35° (2023)
- Record low
- 28°−2° (2022)
- Heating degree days
- 219
- Cooling degree days
- 27
Hillsboro in OctoberThis month
Highs average 58°14° and lows 36°2°, with 2.8 in70 mm of precipitation in a typical October.
- Record high
- 86°30° (2019)
- Record low
- 18°−8° (2018)
- Heating degree days
- 567
- Cooling degree days
- 1
Hillsboro in November
Highs average 43°6° and lows 25°−4°, with 2 in51 mm of precipitation in a typical November.
- Record high
- 73°23° (2022)
- Record low
- −4°−20° (2014)
- Heating degree days
- 940
- Cooling degree days
- 0
Hillsboro in December
Highs average 30°−1° and lows 13°−10°, with 1.6 in40 mm of precipitation in a typical December.
- Record high
- 65°18° (2021)
- Record low
- −23°−31° (2013)
- Heating degree days
- 1344
- Cooling degree days
- 0