Thursday, September 5, 2013

Temperature Parity for Alaska's Largest Cities

Looking at the 1981-2010 climate normals, September 5th (today) is the day when the normal daily temperature for Juneau is identical to the normal daily temperature for Anchorage. Those temperatures are slightly warmer than the normal temperature for Fairbanks. It turns out that August 17th/18th is the date when the three cities are closest together in terms of their normal daily temperature. Again, this is strictly an assessment of the NCDC climate normals.

If we go back and look at the actual temperatures for these three cities since 1945, the same basic pattern appears; i.e., May and August are relatively similar for all three cities.

The first chart below shows the percentage of days when each city had the warmest daily average temperature. As you would expect, Fairbanks leads the way during the summer months and Juneau during the winter months. The second chart looks at the percentage of days when each city had the coldest daily average temperature. This time, Fairbanks dominates the winter months but all three cities have relatively similar values in the early summer months. The table at the bottom shows an example of how the numbers were calculated. (Note: between 1945 and 2012, there were 14 days when all three cities had identical daily average temperatures)