Decatur, Illinois vs Janesville Climate
79%matchDecatur vs Janesville: a 79% climate match. Compared with Decatur, Janesville has 8°F (4°C) colder winter nights, 5°F (3°C) cooler summer days and less rain in winter.
Decatur gets 41 in (1034 mm) of rain a year and Janesville 35 in (887 mm). July is the warmest month in both, with highs of 88°F (31°C) in Decatur and 84°F (29°C) in Janesville.
Climate fingerprints: ring color = average temperature, thickness = rain. January at the top.
Month by month
Highs and lows (°F)
DecaturJanesvillesolid = high, dashed = low
Rain (in per month)
DecaturJanesville
Monthly averages
| Month | High | Low | Rain | |||
|---|---|---|---|---|---|---|
| Decatur | Janesville | Decatur | Janesville | Decatur | Janesville | |
| Jan | 37°F(3°C) | 29°F(-2°C) | 20°F(-7°C) | 12°F(-11°C) | 2.2 in(55 mm) | 1.3 in(32 mm) |
| Feb | 41°F(5°C) | 33°F(0°C) | 23°F(-5°C) | 15°F(-9°C) | 2.0 in(51 mm) | 1.3 in(34 mm) |
| Mar | 53°F(12°C) | 45°F(7°C) | 33°F(1°C) | 26°F(-3°C) | 3.0 in(75 mm) | 2.2 in(55 mm) |
| Apr | 65°F(19°C) | 58°F(15°C) | 43°F(6°C) | 36°F(2°C) | 4.1 in(105 mm) | 3.6 in(92 mm) |
| May | 76°F(25°C) | 71°F(22°C) | 53°F(12°C) | 47°F(9°C) | 4.9 in(125 mm) | 3.6 in(91 mm) |
| Jun | 85°F(29°C) | 80°F(27°C) | 62°F(17°C) | 57°F(14°C) | 4.6 in(118 mm) | 4.6 in(116 mm) |
| Jul | 88°F(31°C) | 84°F(29°C) | 66°F(19°C) | 62°F(16°C) | 4.3 in(110 mm) | 3.7 in(94 mm) |
| Aug | 87°F(30°C) | 82°F(28°C) | 64°F(18°C) | 59°F(15°C) | 3.4 in(86 mm) | 3.9 in(99 mm) |
| Sep | 81°F(27°C) | 75°F(24°C) | 56°F(13°C) | 51°F(11°C) | 3.3 in(83 mm) | 4.1 in(103 mm) |
| Oct | 68°F(20°C) | 62°F(17°C) | 45°F(7°C) | 40°F(4°C) | 3.0 in(77 mm) | 2.7 in(69 mm) |
| Nov | 53°F(12°C) | 47°F(8°C) | 34°F(1°C) | 29°F(-2°C) | 3.1 in(80 mm) | 2.2 in(55 mm) |
| Dec | 41°F(5°C) | 34°F(1°C) | 25°F(-4°C) | 18°F(-8°C) | 2.7 in(69 mm) | 1.9 in(47 mm) |
1991–2020 averages, by calendar month.