Granite Bay State Marine Park Weather Forecast
- 45
- 51
Rain Showers
- 42
- 54
Decreasing Clouds
- 43
- 52
Rain Likely
- 44
- 49
Rain Showers
- 44
- 49
Rain Showers
- 43
- 49
Rain Showers
- 43
- 50
Rain Showers
Today 21 Sep West Prince William Sound & Whittier
Showers likely. Highs in the lower 50s.
Tonight 21 Sep West Prince William Sound & Whittier
Mostly cloudy with a chance of rain Showers. Lows in the 40s. East wind 10 to 15 Mph.
Granite Bay State Marine Park Temperature Statistics
September Temperature
Portage, Portage Glacier (25.5 miles)
Lowest 2 September, 2026
30.9 °FAverage September
51.5 °FHighest 11 September, 2026
68 °F
Climate (2021–2026)
Portage, Portage Glacier (25.5 miles)
Average Low 2021–2026
32.2 °FAverage 2021–2026
38.2 °FAverage High 2021–2026
43.8 °F