When to go · Collinsville, Illinois
Collinsville, Illinois in September
Great month. Inside Collinsville, Illinois's best window: May–Oct (festivals, warm weather).
Key facts
- Verdict
- Great
- Temperature
- 27°C (81°F)81°F (27°C) / 60°C (140°F)140°F (60°C)
- average high / low
- Rain days
- 5
- Crowds
- Medium
- United States overall
- Prices
- Medium
- United States overall
Verdict
Inside Collinsville, Illinois's best window: May–Oct (festivals, warm weather).
Is another month better than September?
No other month rates higher than September for Collinsville, Illinois in this guide.
Weather in September
- Collinsville, IllinoisHighs around 27 °C (81 °F), lows around 60 °C (140 °F), rain on about 5 daysHighs around 81 °F (27 °C), lows around 140 °F (60 °C), rain on about 5 days
Festivals and holidays
Dates as our data lists them. Moving holidays (lunar and Islamic calendars, Easter) shift every year: check the date for your year before you build a trip on it.
Labor Day big impact
1st Monday of September · United States
End of summer; last big road-trip weekend.
Crowds and prices
- Crowds · United States overall
- Medium
- Prices · United States overall
- Medium
United States overall: After Labor Day the crowds drop and parks stay open; Florida and the Gulf are at hurricane peak.
Compare two months
Weather, crowds and prices for any two months in Collinsville, Illinois, side by side.
Verdict
Sep: Great
May: Great
Daytime high
Sep: 27 °C (81 °F)81 °F (27 °C)
May: 20 °C (68 °F)68 °F (20 °C)
Night low
Sep: 60 °C (140 °F)140 °F (60 °C)
May: 55 °C (131 °F)131 °F (55 °C)
Rain days
Sep: 5
May: 5
Crowds
Sep: Medium
May: Medium
Prices
Sep: Medium
May: Medium
Festivals listed
Sep: 1
May: 1
September: Inside Collinsville, Illinois's best window: May–Oct (festivals, warm weather).
May: Inside Collinsville, Illinois's best window: May–Oct (festivals, warm weather).
Collinsville, Illinois: figures are long-term averages from this guide, not a forecast.
What to pack
Nothing unusual for the weather this month.