Island Park Reservoir Weather Forecast
- 28
- 46
Increasing Clouds
- 25
- 49
Rain Showers Likely
- 24
- 45
Mostly Sunny
- 28
- 50
Partly Sunny
- 27
- 52
Mostly Sunny
- 29
- 53
Mostly Sunny
Today 18 Oct Centennial Mountains/Island Park
Sunny. Highs 44 to 51.
Tonight 18 Oct Centennial Mountains/Island Park
Partly cloudy. Lows 25 to 35.
Island Park Reservoir Temperature Statistics
October Temperature
West Yellowstone (27.3 miles)
Lowest 7 October, 2025
19.4 °FAverage October
41.1 °FHighest 9 October, 2025
69.8 °F
Climate (2020–Present)
West Yellowstone (27.3 miles)
Average Low 2020–2025
33.6 °FAverage 2020–2025
50.8 °FAverage High 2020–2025
66 °F