The main purpose of this ongoing blog will be to track planetary extreme, or record temperatures related to climate change. Any reports I see of ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉
Main Topic: U.S. Average Temperature Forecast for Summer
Dear Diary. It will be the start of meteorological summer by June 1st, so once again as we do on this blog, it is time to make a forecast for the coming season. As forecast, Spring 2025 had above average temperatures for lower 48 states, another sign of anthropogenic climate change.
At the very start of summer, it’s time for me to make another attempt at a forecast for average seasonal temperatures in the U.S. This forecast will be very broad and not specific for any one state comprising the continental United States (or lower 48 states).
So how did the forecast work out for Soring 2025? Here is a link to the post for that forecast:
By June 10th the National Center for Environmental Information will finish their climatological assessment for Spring 2025 so our verification is not complete as of May 29th. Let’s do fill in ranking numbers with 1 being the coldest and 131 warmest for a verification for months during 2025, which have already been assessed:
Here are my two cents for a broad, rough forecast for the U.S. for Spring 2025, which I guarantee to be warmer than this past spring, of course, as the amount of daylight increases across the Northern Hemisphere.
I like to look at spikes on graphs because they can tell us something. Last year we had a big warming spike for 2024, so it stands to reason that we will not see back-to-back warmest years on record unless our climate is truly way out of whack with global warming becoming exponential. Summer 2024 was right up there with some of the hottest summers on record, being 4th warmest:
I would expect a slight downward tick on the above chart for Summer 2025, but the season should be well above average.
Second, I like to look at water temperature anomalies surrounding North America just before the start of a season to get a sense of how much potential anomalous heat can be added to the atmosphere across the continent. Here is what we see:
Warm SST’s have encircled North America over the winter, but cooler than average waters have made an appearance off of California. Mostly warmer than average conditions, particularly across the Gulf of Mexico, lead me to think that SST influence will be a positive factor for this coming season. Also, it appears that the current ENSO Pacific is in neutral phase and won’t be much of a factor.
We do note that the first half of June will be warm across the eastern and central U.S. while cooler than average in the West:
June should be an above average month but not record warmest.
Here is the National Weather Service forecast for Summer 2025:
Ouch! If the Weather Service is correct, we should see another top ten hottest summer season. Also, western wildfires would be a big issue going into the fall.
I can’t pinpoint one area where their forecast is incorrect, but overall, I think that this summer’s ranking should verify a tad below that of Summer 2024, which was 127.
Next, we can get another clue looking at prior National Center for Environmental Information ranking and temperature record count data. For this I like to drag out my “Record Scoreboard” (updated through 5/28/2025):
For these data sets all monthly ratios of > 10 to 1 DHMX to DLMN or > 10 to 1 DLMN to DHMX are in bold type. The rankings are for the lower 48 states with the warmest ranking since 1895 of average temperatures being 131 and 1 being the coldest as of 2025. Blue colors represent cold months and red warm. Those months and years with counts close to a 1 to 1 ratio of highs to lows are colored black. Boldly red-, blue-, or purple-colored months, such as January 2020 and October 2024, have ratios of >10 to 1 daily record highs to lows or <1 to 10 daily record highs to lows, and are either historically hot or cold, most of which have made news. All-time record hot or cold ranked months are highlighted in purple. I’ve subtracted Alaska records so we can better compare apples to apples with record totals and rankings for the lower 48 states.
Looking at trends, warm months should continue since it does not look like we are due for a cooler than average month like that of January 2025.
I’m predicting that all three months of Summer 2025 will be above average with June being the most likely month to see temperatures closer to average and August the warmest. Here is the link to avg. rankings per year for the lower 48 states since 1895:
https://www.ncdc.noaa.gov/cag/national/rankings
Not all seasons in the near future will see above average temperatures, but seasonal forecasters are beginning to “chuck it,” discounting colder than average scenarios due to carbon pollution.
Here are all seasons ranked for the last decade:
The last time we had a below average summer season was before 2015. An average ranking on the above chart would be 65.5 as of 2025. Will Summer 2025 buck this trend? I think not..
Here is my bottom-line forecast for Summer 2025:
“I think that Summer 2025 will be ranked above average. I’m going to forecast that the Summer 2025 ranking will be around 115 + or – 10, with above average confidence given all of the factors written within this post.“
My forecast for Winter 2024/25 of a ranking of 90 + or – 10 was 14 rankings too cool, but not too bad considering that the upper end of my forecast was 100, and the verification was at 114.
We will see how well my forecast ranking of near 100 for Spring 2025 worked out in a few days.
As of 2025 the top ranking for any month or season would be 131 since climatological rankings for the United States started in the year 1895. Carbon pollution is definitely making below average seasons rarer. As stated, I’m going to guess that Summer 2025 gets ranked at 115 + or – 10, and with above average confidence given all of the factors in this post.
Have a fantastic summer but be weather aware of brutal summer heat. Do not leave children and pets in hot cars, which could be tragic, fatal mistakes.
Here are more “ETs” recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks, as well as any extreme precipitation reports:
Here is More Climate News from Thursday:
(As usual, this will be a fluid post in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)