How Much Has Global Warming Changed July 4th Temperatures Over Washington State?

Walking my dog yesterday, I ran into a neighbor who asked whether July 4th temperatures in our area had changed much under global warming. 

I promised to run the numbers... and here are the results.  

Be prepared to be surprised 😀.

Starting at Olympia, on the western side of the state, there is almost no trend in July 4 daily average temperatures since the 1940s! (The purple line is the linear trend).

What about the highest temperatures each year on July 4 in Olympia?   

No trend!  

OK, now let's check Yakima in eastern Washington! 

The July 4 average temperature trend is slightly upward (a little less than 2 F over 75 years).

The trend in the maximum temperatures at Yakima is similar.  Modest upward increase.

And then there is Spokane, over the northeast side of Washington (below).  Very little trend in average July 4th temperatures or in the highest temperatures on that date.

What about precipitation on July 4th in Olympia?  As shown below, there is little evidence of a long-term trend.

Anyway,  a big yawn is appropriate for the July 4 trends in temperature over Washington State.

The planet is slowly warming for sure, but the temperature trends in Washington State are very, very modest.

But you might get a different answer if you relied on AI.  

I asked Google's AI to create a graphic summarizing the July 4 temperature trend over Washington.

It created the graphic below, with a dramatic upward trend over Washington from 26F to 80°F since 1990 (below).  Was it really below freezing in July in 1990?

Total nonsense.