Thursday, July 16, 2015

June Was Record Setting Hot

Although we've known for some time that we saw the warmest June on record at the Salt Lake City International Airport, recently released numbers from the National Centers for Environmental Information show it was also warmest for the statewide average temperature, just topping 1918.  

Source: NCEI
For January to June, the statewide average temperature was the 2nd highest on record, just behind 1934, which serves as the ultimate "black swan" year in our instrumented record.  

Source: NCEI
Fortunately, Mother Nature has dialed it back a bit so far this July and we're running only 3.8ºF above the 1981-2010 monthly average for the minimum temperature and 2.4ºF below average on the maximum temperature so far.  The latter has made late afternoon and evening workouts far more bearable than they typically are in July.


  1. It seems like one of the biggest contributing factors to the mean temperature increasing is the minimums in the summer seem much warmer these days than the historic averages. Why is that? Airport location? More concrete retaining heat?

    I moved from Nevada and while the summer highs are comparable, the average low temp in Western Nevada during summer was in the low 50s which made the season much more bearable. Very similar climate and elevation... What's the reason they cool off so much more at night?

    1. There are a host of factors that contribute to the size of the nocturnal cooling. Yes, in Salt Lake, the urbanization certainly contributes to higher minima, however, the shape of the terrain is also a factor. There is a persistent down-valley flow that helps stir the atmosphere some in the Salt Lake Valley. That mixing would help to keep things a bit warmer even if the city wasn't here. If you go to the Rush Valley, which is really an enclosed basin to the southeast of Salt Lake on the other side of the Oquirrhs, it gets really cold at night because the enclosed basin results in lighter winds.

      Irrigation is likely another factor. I would expect the daily temperature range to be smaller over irrigated areas than unirrigated areas.