The highest day temperature in September 2026 was 57°F. The lowest night temperature was 32°F. The average values for day and night temperatures during September were 44.6°F и 38.7°F respectivly.

The average sea surface temperature in September 2026 for Girdwood was 48.3°F. The maximum and minimum values were 41.4°F and 51.8°F respectively.

Most of the days in September are gloomy but you can also expect sunny days.

Precipitation total in September for Girdwood is 2.8 in. It makes september one of the most rainy months of the year.

The average wind speed in September is 5.4 mph. This value is relatively stable throughout the year.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Girdwood in September is 2.7 hours.