Plum Island Weather Forecast
- 44
- 67
Mostly Sunny
- 43
- 69
Partly Sunny
- 43
- 69
Mostly Sunny
- 56
- 70
Mostly Cloudy
- 54
- 79
Partly Sunny
- 51
- 74
Partly Sunny
Today 9 Oct La Salle
Sunny. Highs in the mid 60s. Southeast Winds around 5 Mph.
Tonight 9 Oct La Salle
Mostly clear. Lows in the lower 40s. Southeast Winds around 5 Mph.
Plum Island Temperature Statistics
October Temperature
Illinois Valley Regional Airport (8.1 miles)
Lowest 7 October, 2025
50 °FAverage October
69.9 °FHighest 3 October, 2025
89.8 °F
Climate (2020–Present)
Illinois Valley Regional Airport (8.1 miles)
Average Low 2020–2025
43.2 °FAverage 2020–2025
52.7 °FAverage High 2020–2025
62.2 °F