When to go · O'Fallon, Illinois
O'Fallon, Illinois in January
Avoid month. Listed as a month to avoid: Jul–Aug (humid), Dec–Feb (cold).
Key facts
- Verdict
- Avoid
- Temperature
- 4°C (39°F)39°F (4°C) / −6°C (21°F)21°F (−6°C)
- average high / low
- Rain days
- 8
- Crowds
- Low
- United States overall
- Prices
- Low
- United States overall
Verdict
Listed as a month to avoid: Jul–Aug (humid), Dec–Feb (cold).
Is another month better than January?
January is rated avoid. These months rate higher:
Weather in January
- O'Fallon, IllinoisHighs around 4 °C (39 °F), lows around -6 °C (21 °F), rain on about 8 daysHighs around 39 °F (4 °C), lows around 21 °F (-6 °C), rain on about 8 days
Crowds and prices
- Crowds · United States overall
- Low
- Prices · United States overall
- Low
United States overall: Cold and snowy north and in the mountains; Florida, Hawaii and the desert Southwest are the picks.
Compare two months
Weather, crowds and prices for any two months in O'Fallon, Illinois, side by side.
Verdict
Jan: Avoid
Apr: Great (better)
Daytime high
Jan: 4 °C (39 °F)39 °F (4 °C)
Apr: 20 °C (68 °F)68 °F (20 °C)
Night low
Jan: -6 °C (21 °F)21 °F (-6 °C)
Apr: 7 °C (45 °F)45 °F (7 °C)
Rain days
Jan: 8 (better)
Apr: 11
Crowds
Jan: Low
Apr: Medium
Prices
Jan: Low
Apr: Medium
Festivals listed
Jan: 0
Apr: 1
January: Listed as a month to avoid: Jul–Aug (humid), Dec–Feb (cold).
April: Inside O'Fallon, Illinois's best window: Apr–Jun, Sep–Oct.
O'Fallon, Illinois: figures are long-term averages from this guide, not a forecast.
What to pack
- A warm coat, hat and gloves for mornings and evenings