September Outlook

By Rick Thoman
Alaska Climate Specialist
Alaska Center for Climate Assessment and Preparedness
International Arctic Research Center/University of Alaska Fairbanks

The September outlook from NOAA’s Climate Prediction Center favors above normal temperatures for the whole month all across western Alaska, while neither above nor below normal precipitation is favored.
September is a month of rapid transitions. Nome loses more than three hours of possible sunshine and average temperatures drop by more than ten degrees Fahrenheit.
In the past 118 years, temperatures during the month have ranged from a high of 71°F in 1979 to a low of 9°F during the extraordinarily chilly September 1992.
In most of western Alaska, September is either the second or third wettest month of the year.
At Nome, the total precipitation during the month has ranged from just under eight inches in 1986 to only 0.06 inches 2008, though during the past century there’s no long-term trend of the September total precipitation.
The first snowflakes of the season frequently occur in late September, but at low elevations near the coast, accumulating snow is unusual due to the moderating influence of the still warm ocean waters. At Nome, there's been two or more inches of snow in September just five times in the past 100 years, most recently in 2004. Snow is of course common at higher elevations, and occasionally near town. Even a small increase in elevation can result in significant accumulation differences.