Was This a Hot Summer?

With the seasonal change to Fall, it's a good opportunity to look back at the summer of 2024.  Would you say it was a hot one?  A dry one?  Just about normal?

For those with short memories (like me), June of this year was just about as "normal" as you can get, both with temperature and moisture.  But then July rolled around with a very scorching stretch of days.  Spokane Airport reach a high of 90F or better for an impressive 20 consecutive days.  To put that in context, Spokane averages only 20 days of 90F weather for the entire summer.  So if I had asked you at the end of July what kind of summer we were having, you'd likely have answered that it was a hot one.  And it was a hot July across the western U.S.  Below shows the ranking for each state's average July temperature.  Red means it was the hottest on record (California, New Hampshire and Florida).  Orange indicates it was one of the 10% hottest summers for the West as well as the East coast.

August started off hot for the first few days.  But then things cooled off a bit for the rest of the month, meaning it was only a tad warmer than normal.  Nothing to write home about.  In fact, August wasn't exceptionally hot anywhere in the contiguous 48 states.

So when you look at July and August together, the summer of 2024 was a hot one in the West and the northeast.  Another way to look at it:  Spokane wound up with 36 days of 90F or warmer for the year, far exceeding the average of 20 days.  This includes 5 such days at the start of September.

It's worth pointing out that Spokane Airport set a record for the hottest July ever, beating the incredibly hot 2021.  But was it?

As we all know, Spokane Airport sits about 400 feet higher in elevation than the downtown Felts Field airport.  Thus, Felts Field averages a high temperature in July of 87.1F, compared with 84.4F at Spokane International Airport.  But in July of this summer, Spokane International's average high temperature was actually 0.1F warmer than Felts Field.  I'm not sure that's ever happened before.  Both locations hit 107F on the 21st, which certainly seems odd.  In fact, Spokane International was warmer than Felts Field on 7 days in July, and equaled the high temperature on 17 days.  Was something going on?

The answer is likely revealed in the first few days of August.  The NWS staff realized that the temperatures at Spokane International were just too hot to be real.  This became obvious on August 2nd when Spokane Airport hit 108F, which was just one degree shy of the all-time record.  Meanwhile, nearby Fairchild AFB was only 101F and Felts Field was 106F.

As a result, the NWS staff decided to use the high and low temperatures from Fairchild AFB as the official readings, until the thermometer and Spokane International could be replaced.

So it's likely that the erroneous temperature sensor at Spokane Airport went bad back in July or possibly even June.  This likely accounts for why July shows up in the archives as the hottest ever in Spokane.  Is there any way to confirm this?  Actually there is.

A weather balloon has been launched routinely at Spokane Airport and NWS Spokane since 1948.  We can look at the hottest temperatures at the 5000' elevation from the balloon data to see if this past summer shows up.

As you can see, all of the top six hottest temperatures at 5000' were from the record event of 2021 (when we set our all-time record of 109F), and the 1961 event (which was when our previous record of 108F was set).  2024 doesn't show up in the list, despite having two days of 107F.  

In summary, 2024 was a hot summer.  And this wasn't just at Spokane Airport.  Nearly every county in Washington had a July-August that was in the top 10% of warmest months.

Speaking of warmth, the 80s are due to make a return to our area on Tuesday and Wednesday before a cold front will drop us down into the 70s and upper 60s for the rest of the week.  We could see a few showers on Wednesday evening along with gusty winds.  But overall, we're still looking at mild and mostly dry autumn weather into early October.  

Spokane has only had 0.03" of rain this month.  If it fails to receive any more in the next 9 days, it would be in the top 10 of driest Septembers.  Despite all of the cool weather systems this month, the rain has largely been missing us to the south and east.  Rains have moved from eastern Oregon into the southern ID panhandle and Montana.