June Is the New July

I woke up this morning thinking it must be the end of July.  Heat.  Thunderstorms. Basic yuckiness.  Graphs from the National Weather Service show only 6 days this month with a maximum temperature below "normal" and only 4 days with a minimum temperature below normal.  

Normal for the National Weather Service is currently based on the 30-year average for 1991-2020, but warming of the climate system and expansion of the Wasatch Front urban area was already having an influence during that period.  Thus, I thought I'd take a look back at how this June so far compares with the Julys we used to have around here.  

So far, this June (based on data from the 1st to the 26th) has an average temperature at KSLC of 77.3°F.  It is evident from the graph below that this is much warmer than the typical range of temperatures observed prior to about 2000.  In fact, it is the 2nd warmest such period on record, behind only 2021.  

Source: https://xmacis.rcc-acis.org/

I wondered how that compared to the Julys we had around here back in the day, so I pulled those numbers.  It turns out that so far this June is comparable to the average July temperature during the 21st century (based on data from 1901–2000) of 77.05°F.  It is also comparable to the 30-year averages for Julys from 1941–1970 (77.0°F), 1951–1980 (77.5°F), and 1961–1990 (77.8°F).  

You know, the good old days.  

Since there are always questions about the Salt Lake Airport observations, I'll add that the Bountiful Bench cooperative site has also experienced it's 2nd warmest June 1–26 on record this year (tied with 1988), behind only 2021.  Records there only go back to 1975, so comparisons of with the climate of the 20th century are not possible for that site.