Columbia, Missouri vs O'Fallon, Illinois Climate
98%matchOn climate, O'Fallon is a 98% match for Columbia. Very close: temperatures within 2°F (1°C), with similar rain, humidity and sun.
Columbia gets 40 in (1012 mm) of rain a year and O'Fallon 40 in (1027 mm). July is the warmest month in both, with highs of 89°F (32°C) in Columbia and 88°F (31°C) in O'Fallon.
Climate fingerprints: ring color = average temperature, thickness = rain. January at the top.
Month by month
Highs and lows (°F)
ColumbiaO'Fallonsolid = high, dashed = low
Rain (in per month)
ColumbiaO'Fallon
Monthly averages
| Month | High | Low | Rain | |||
|---|---|---|---|---|---|---|
| Columbia | O'Fallon | Columbia | O'Fallon | Columbia | O'Fallon | |
| Jan | 40°F(4°C) | 39°F(4°C) | 21°F(-6°C) | 23°F(-5°C) | 1.7 in(42 mm) | 2.4 in(60 mm) |
| Feb | 46°F(8°C) | 45°F(7°C) | 25°F(-4°C) | 26°F(-3°C) | 1.9 in(48 mm) | 2.4 in(61 mm) |
| Mar | 57°F(14°C) | 56°F(13°C) | 35°F(2°C) | 35°F(2°C) | 2.9 in(74 mm) | 3.3 in(84 mm) |
| Apr | 68°F(20°C) | 67°F(20°C) | 45°F(7°C) | 45°F(7°C) | 4.4 in(112 mm) | 4.0 in(101 mm) |
| May | 77°F(25°C) | 77°F(25°C) | 55°F(13°C) | 56°F(13°C) | 5.6 in(141 mm) | 4.9 in(124 mm) |
| Jun | 85°F(30°C) | 85°F(30°C) | 64°F(18°C) | 65°F(18°C) | 4.4 in(112 mm) | 4.2 in(106 mm) |
| Jul | 89°F(32°C) | 88°F(31°C) | 68°F(20°C) | 68°F(20°C) | 4.1 in(105 mm) | 3.8 in(96 mm) |
| Aug | 89°F(31°C) | 87°F(31°C) | 66°F(19°C) | 66°F(19°C) | 3.3 in(83 mm) | 3.3 in(83 mm) |
| Sep | 81°F(27°C) | 81°F(27°C) | 57°F(14°C) | 58°F(14°C) | 3.6 in(92 mm) | 3.7 in(94 mm) |
| Oct | 69°F(21°C) | 69°F(21°C) | 46°F(8°C) | 46°F(8°C) | 3.0 in(76 mm) | 2.8 in(72 mm) |
| Nov | 55°F(13°C) | 55°F(13°C) | 35°F(2°C) | 36°F(2°C) | 2.8 in(71 mm) | 3.0 in(77 mm) |
| Dec | 44°F(7°C) | 44°F(7°C) | 25°F(-4°C) | 27°F(-3°C) | 2.2 in(56 mm) | 2.7 in(69 mm) |
1991–2020 averages, by calendar month.