When to go · Monticello, Illinois
Monticello, Illinois in September
Great month. Inside Monticello, Illinois's best window: May–Oct (park and train season); late Sep–Oct for foliage.
Key facts
- Verdict
- Great
- Temperature
- 26°C (79°F)79°F (26°C) / 14°C (57°F)57°F (14°C)
- average high / low
- Rain days
- 8
- Crowds
- Medium
- United States overall
- Prices
- Medium
- United States overall
Verdict
Inside Monticello, Illinois's best window: May–Oct (park and train season); late Sep–Oct for foliage.
Is another month better than September?
No other month rates higher than September for Monticello, Illinois in this guide.
Weather in September
- Monticello, IllinoisHighs around 26 °C (79 °F), lows around 14 °C (57 °F), rain on about 8 daysHighs around 79 °F (26 °C), lows around 57 °F (14 °C), rain on about 8 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 Monticello, Illinois, side by side.
Verdict
Sep: Great
May: Great
Daytime high
Sep: 26 °C (79 °F)79 °F (26 °C)
May: 24 °C (75 °F)75 °F (24 °C)
Night low
Sep: 14 °C (57 °F)57 °F (14 °C)
May: 12 °C (54 °F)54 °F (12 °C)
Rain days
Sep: 8 (better)
May: 11
Crowds
Sep: Medium
May: Medium
Prices
Sep: Medium
May: Medium
Festivals listed
Sep: 1
May: 1
September: Inside Monticello, Illinois's best window: May–Oct (park and train season); late Sep–Oct for foliage.
May: Inside Monticello, Illinois's best window: May–Oct (park and train season); late Sep–Oct for foliage.
Monticello, Illinois: figures are long-term averages from this guide, not a forecast.
What to pack
Nothing unusual for the weather this month.