With mid-80s again today in Fairbanks, the last 7 days are already the warmest week of the summer despite the fact that it was distinctly chilly a week ago. This is a little later than normal to be observing the peak warmth of the season, although the absence of heat was itself a bit unusual until now.
The chart below shows a histogram of the dates of peak weekly mean temperatures in Fairbanks, based on daily highs (red), daily lows (blue), and daily mean temperatures (gray). Daily high temperatures tend to peak from late June through mid-July, but daily low temperatures often rise into mid-July as humidity and cloud cover increase. But by the latter third of July it's distinctly less common to see the summer's warmest weather.