See long range weather forecasts for the next 60 days for the Deep South Region. The Old Farmer's Almanac's scientifically-based, long range forecasts can be used to make more informed decisions about future plans that depend on the weather, from vacations and weddings to sporting events and outdoor activities.
Weather in Alaska in September. The average maximum daytime temperature in Alaska in September is a cool 13Â°C (55Â°F). There are usually 5 hours of bright sunshine each day, which represents 41% of the 13 hours of daylight. The average sea temperature in and around Alaska in September is 12Â°C (54Â°F).
According to Alaska Travel, average highs in the Inside Passage region range from 55 to 65 degrees Fahrenheit during cruise season, with May and September being about 10 degrees colder during the day than the summer months. Hours of daylight range from 14 to 18, with June having the most daylight hours and September having the least. South central Alaska has similar weather, with average temperature highs of 55 degrees Fahrenheit in both May and September; average temperatures range between 62 and 65 degrees F in June, July and August.