Climate Watch

Alaska Climate Specialist Alaska Center for Climate Assessment and Policy, UAF With mild weather lately, and in many areas the accompanying slush that says “spring” in western Alaska, an obvious climate question is: “Is it thawing more, or sooner, in the spring than it used to?”

From the western science perspective, a simple way to look at this question is to ask how (if at all) the number of days at Nome with the temperature getting above freezing has changed over the past century during the spring. Of course, it’s not uncommon for the temperatures to stay below freezing in March, and there have been three Aprils since 1907 when the temperature failed to get above 32°F. Putting March and April together, we see the number of days above freezing has ranged from just one in 1985 and 2006 to as many as 33 back in 1926.

But is there any trend through time?

It turns out that there is, but it’s not a strong increase. The graphic plots the number of days each March and April with high temperatures above freezing. To this we’ve added three categories to characterize the number of days above freezing: more days than normal, near normal and fewer than normal. This shows that prior to the 1920s, eight to 14 days above freezing was typical. Fast forward a hundred years, and nowadays 11 to 18 days above freezing during March and April is typical.

While our changing climate sometimes brings spectacular examples of things we had not seen before, coastal flooding at Little Diomede in February 2018, or Iditarod 2019, with teams headed into Nome on beach with open water in the Bering Sea, just as often change is a slow grind that is not really noticeable year-to-year. Thankfully, Nome has one of the longest climate records of any place in Alaska, so we can see these long-term changes both from the western science perspective and from the elders’ perspective.