Janesville Climate by Month
Janesville, Wisconsin, United States
Warm summers and freezing winters, with rain spread through the year.
Warm summers and freezing winters, with rain spread through the year: that's Janesville's climate in short. July is the warmest month, with highs around 84°F (29°C); January is the coolest at 29°F (-2°C), and nights dip to 12°F (-11°C). About 35 in (887 mm) of rain falls in a typical year, with no clear rainy season.
- Warmest month
- 84°F(29°C)
- Average high, July
- Coldest nights
- 12°F(-11°C)
- Average low, January
- Rain per year
- 35 in(887 mm)
- No clear rainy season
- Humidity
- 74%
- Sunniest: July
Best and worst months in Janesville
Best for weatherSeptember is the best time for weather in Janesville: highs near 75°F (24°C) and about 4.1 in (103 mm) of rain a month.
Least pleasantJanuary and February are the least pleasant; January is the coldest, with highs of only 29°F (-2°C).
Comfort combines how close the afternoon high is to 75°F (24°C) with how much rain falls and how humid it is. See where the weather is best in September.
Temperature and rain through the year
Highs and lows (°F)
Average highAverage low
Rain (in per month)
Janesville weather by month
| Month | High | Low | Rain | Humidity | Sun |
|---|---|---|---|---|---|
| JanJanuary | 29°F(-2°C) | 12°F(-11°C) | 1.3 in(32 mm) | 80% | 1.5 |
| FebFebruary | 33°F(0°C) | 15°F(-9°C) | 1.3 in(34 mm) | 92% | 2.5 |
| MarMarch | 45°F(7°C) | 26°F(-3°C) | 2.2 in(55 mm) | 71% | 3.6 |
| AprApril | 58°F(15°C) | 36°F(2°C) | 3.6 in(92 mm) | 63% | 4.5 |
| MayMay | 71°F(22°C) | 47°F(9°C) | 3.6 in(91 mm) | 64% | 5.2 |
| JunJune | 80°F(27°C) | 57°F(14°C) | 4.6 in(116 mm) | 71% | 5.8 |
| JulJuly | 84°F(29°C) | 62°F(16°C) | 3.7 in(94 mm) | 69% | 6.0 |
| AugAugust | 82°F(28°C) | 59°F(15°C) | 3.9 in(99 mm) | 75% | 5.1 |
| SepSeptemberBest | 75°F(24°C) | 51°F(11°C) | 4.1 in(103 mm) | 70% | 4.3 |
| OctOctober | 62°F(17°C) | 40°F(4°C) | 2.7 in(69 mm) | 71% | 2.7 |
| NovNovember | 47°F(8°C) | 29°F(-2°C) | 2.2 in(55 mm) | 78% | 1.7 |
| DecDecember | 34°F(1°C) | 18°F(-8°C) | 1.9 in(47 mm) | 84% | 1.3 |
1991–2020 averages. Sun is solar radiation in kWh/m² per day. Highlighted: the most comfortable months.
Places with a similar climate
All 20 places like Janesville →- 🇺🇸DubuqueIowa, United States · Pop. 59k99%matchSame winter lowsSame summer highsJanesville vs Dubuque →
- 🇺🇸WaterlooIowa, United States · Pop. 68k99%matchSame winter lowsSame summer highsJanesville vs Waterloo →
- 🇺🇸West AllisWisconsin, United States · Pop. 61k99%matchSimilar rainfallSame humidityJanesville vs West Allis →
- 🇺🇸MarshalltownIowa, United States · Pop. 28k99%matchSame summer highsSame winter lowsJanesville vs Marshalltown →
- 🇺🇸AmesIowa, United States · Pop. 65k99%matchSame winter lowsSame summer highsJanesville vs Ames →