Crystal Lake Weather Forecast
- 57
- 79
Mostly Sunny
- 45
- 74
Mostly Sunny
- 52
- 71
Partly Sunny
- 56
- 67
Mostly Cloudy
- 59
- 73
Partly Sunny
- 58
- 76
Chance Rain Showers
Today 18 Sep Sullivan
Sunny. Highs in the upper 70s. Northwest Winds around 5 Mph.
Tonight 18 Sep Sullivan
Mostly clear. Lows in the mid 50s. Northwest Winds around 5 Mph.
Crystal Lake Temperature Statistics
September Temperature
Williamsport - Lycoming County Airport (14.3 miles)
Lowest 8 September, 2025
44.1 °FAverage September
64.8 °FHighest 13 September, 2025
86 °F
Climate (2020–Present)
Williamsport - Lycoming County Airport (14.3 miles)
Average Low 2020–2025
43.9 °FAverage 2020–2025
53.1 °FAverage High 2020–2025
63.3 °F