The cool conditions have been quite persistent for nearly two months now.
As a result of the chilly weather, some of the fresh water lakes on the North Slope are still frozen, as seen in the land-cover imagery from the Suomi polar orbiting satellite. The image below was taken at 4pm today; ice is indicated by light blue colors in the Arctic Ocean and the larger lakes of the North Slope.
Today's webcam images from the observatory at Teshekpuk Lake (the large lake in the image above) confirm the presence of ice cover:
The same images from yesterday showed more ice cover near the shore; meltout appears to be getting into full swing now. Compare the situation to what was observed on June 17 of last year: https://ak-wx.blogspot.com/2017/06/north-slope-thaw.html
The blame for the persistent chill lies with a trough that has transported Arctic air south into northern and interior Alaska; Fairbanks felt the effects of this about a month ago. Here's a map of the 500mb height anomaly for the month of June.
However, the 925mb temperature map for June puts Alaska's cool anomaly in perspective - see below. In contrast to the localized and rather mundane region of chill over northern Alaska, the central part of Arctic Siberia saw a very large and pronounced warm anomaly, and indeed the Siberian warmth was very extreme by historical standards. At the town of Saskylakh at 72°N (nearly the same as Utqiaġvik), the June mean temperature of 60.0°F was more than 5°F above any other June, with data back to 1936, and the month was a remarkable 17.5°F above the 1981-2010 normal.