Summer Starts After the 4th of July

When I first arrived to this area in the spring of 1995, we had a common saying at the office: Summer doesn’t start until after the 4th of July. Blue-tarp camping was common on the Memorial Day weekend,  and even the Independence Day holiday was no guarantee of warm weather. In fact the National Weather Service in Seattle had determined that summer didn’t start there until July 12. 

But in the last 10 years, we’ve had some rather hot Junes, calling our phrase into question. However, 2024 has followed the old script. June was far from a summer month. After yesterday’s storms, the rainfall for June in Deer Park was exactly normal; 1.90”. And the average temperature was also, exactly normal. You don’t often see such a “normal” month. I’m guessing some if not most of you felt that this June was colder than normal. But not so. Probably demonstrating that our memories are short. This June was cooler than the previous 3 years, but the same as 2020. 

Here’s the weather map from Monday morning. Our Sunday storm is now in Montana, with a very strong high pressure system developing just off shore. This is a somewhat unusual place for a summertime high pressure to develop. 


This high pressure will start to move onshore slowly over the next few days. Here’s the weather map for the Fourth. 


By the weekend, high pressure is squarely over the West. Again, this is a slightly unusual pattern. High pressure that builds in from the west is usually more progressive, moving through our area for a short hot spell. In this case, the pattern persists for several days. Portland will sizzle with this pattern, reaching triple digits by Saturday. 




By next week, you can see the center of the high (closed circle) has now shifted to the desert Southwest. We call this a Four Corners high and is a familiar feature of summer weather. It’s what drives the Southwest Monsoon, bringing rain to Arizona and New Mexico. 


It also means hot weather for the Inland Northwest. Portland and Seattle will cool off while 90s and 100s will be common in eastern Washington starting Saturday and continuing next week.  Deer Park’s first 90F day is normally June 23, so it’s a bit behind schedule this year. We’ll probably have our first 90F day of this summer on the 5th or 6th of July. 

The high pressure will slowly move east of our area by the end of next week. This will allow temperatures to cool a bit, but still stay warmer than normal. In other words, summer is here to stay.  Here’s the latest outlook for July from the Climate Prediction Center. 




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