Average data for 10 years
1 January
Monday
+1°
−2°
2 January
Tuesday
−1°
−4°
3 January
Wednesday
+2°
−3°
4 January
Thursday
+1°
−1°
5 January
Friday
+1°
−3°
6 January
Saturday
0°
−2°
7 January
Sunday
+2°
−2°
8 January
Monday
+1°
−2°
9 January
Tuesday
+2°
−2°
10 January
Wednesday
+3°
−1°
11 January
Thursday
+6°
+1°
12 January
Friday
+2°
+2°
13 January
Saturday
−1°
−4°
14 January
Sunday
+2°
−3°
15 January
Monday
0°
−2°
16 January
Tuesday
+4°
−2°
17 January
Wednesday
+2°
+2°
18 January
Thursday
+3°
−2°
19 January
Friday
+2°
−1°
20 January
Saturday
+1°
−1°
21 January
Sunday
+1°
−2°
22 January
Monday
+1°
−2°
23 January
Tuesday
+2°
−1°
24 January
Wednesday
+1°
−2°
25 January
Thursday
+2°
−1°
26 January
Friday
+2°
−2°
27 January
Saturday
+2°
−2°
28 January
Sunday
+4°
0°
29 January
Monday
+6°
+3°
30 January
Tuesday
+6°
0°
31 January
Wednesday
+5°
+2°
Cities with similar weather in January
United States
New York
Czech Republic
Karlovy Vary
Poland
Warsaw
Kazakhstan
Aktau
Poland
Gdansk
January in O'Fallon is the snowiest, the windiest, and the coldest month of the year. In January, the weather in O'Fallon is typically cold. Average daily high temperature in January is about 2 degrees above zero. On average, O'Fallon has 10 partly cloudy, 9 sunny, 8 cloudy, 3 rainy, and 1 snowy day in January. The rains are usually light. January as well as February, March, and December is considered the most uncomfortable time to visit O'Fallon.