Summer 2026 was the second-hottest on record in Phoenix

This summer has been Phoenix’s second-hottest on record, according to National Oceanic and Atmospheric Administration data.

Meteorologists define summer as June, July and August. The average temperature for those three months in Phoenix this year was 97 degrees. That ties 2023 for second-hottest ranking. Only the summer of 2024 was hotter, with a three-month average of 98.9 degrees.

National Oceanic and Atmospheric Administration

This year’s extremely hot summer immediately followed Phoenix’s hottest spring on record and hottest winter on record. That puts 2026 on track for the hottest year-round average temperature on the books in Phoenix.

The extreme temperatures have come with public health consequences. Maricopa County has confirmed 136 heat-related deaths so far in 2026, more than double the number that had been counted at the same point last year. Another 605 deaths remain under investigation as potentially heat-linked.

Scientists say the unprecedented heat throughout 2026 has had a strong link to human-caused climate change. Carbon pollution and urban development trap heat close to the earth, even after the sun sets. In the future, climate scientists predict Phoenix will see even longer and more intense heat seasons.

Hear Katherine Davis-Young on The Show with host Mark Brodie

Listen • 6:14

Full conversation on The Show
MARK BRODIE: ... Temperatures are expected to be in the low to mid-100s for the next week or so as we move through September. And as my first guest this morning reports, this has been the second-hottest summer on record in Phoenix. Over June, July, and August, the average temperature was 97 degrees. KJZZ’s Katherine Davis-Young has been reporting on the Valley’s summer heat and the impact it’s had. She’s here now to talk about what she’s found. Good morning, Katie.

KATHERINE DAVIS-YOUNG: Good morning.

MARK BRODIE: So, I think it feels like kind of a distant memory at this point, but May wasn’t so bad here. A lot of people were thinking, "Oh, maybe the summer is going to be the summer we can actually spend outside." Not so.

KATHERINE DAVIS-YOUNG: Yeah, like you said, this actually turned out to be the second-hottest summer on record here. Meteorologists define summer as June, July and August. And the way they get those averages is you take the low temperature each day and the high temperature each day, add them together, divide by two, and that gives you an average. So the average for the whole season was 97 degrees. That ties with 2023 as the second-hottest summer average ever. Only 2024 was hotter.

And like you said, maybe it didn’t feel so bad to you this summer, maybe it didn’t feel so intense. Part of the reason for that is that a lot of the actual record heat that we had this summer happened overnight. So we set seven daily high temperature records throughout the summer, but 16 nights this summer had record-hot low temperatures. So that pushes up those averages. That’s part of the reason that we had this higher average this year.

One of the things, though, that really stands out about this year is how long this heat season has been. You mentioned May was kind of pleasant, but think back to March when we had this unprecedented heat wave. We hit 100 degrees earlier than we ever have in Phoenix before. So this second-hottest summer on record now, that immediately follows our hottest spring on record and our hottest winter on record. So 2026 is on track now to be probably the hottest year-round average for Phoenix ever.

MARK BRODIE: I was trying to put that March span out of my mind, so thank you for bringing it back up. But obviously, these extremely hot temperatures come with major public health consequences. We’ve seen, and you’ve reported, that heat-related deaths have been moving downward over the past few years in Maricopa County. What are we hearing about this year?

KATHERINE DAVIS-YOUNG: Yeah, there was that positive trend for a couple of years there. And unfortunately, those numbers are now moving in the wrong direction again this year. We have 136 heat-related deaths in Maricopa County confirmed so far, which is about double where we were at the same point last year. And there are more than 600 potentially heat-related deaths still under investigation. So I spoke with the Maricopa County medical examiner yesterday, and he told me that we may not see the all-time record high for heat-related deaths this year, but he expects it could be probably close.

MARK BRODIE: Any indication as to why that is? Why heat-related deaths are back to going up?

KATHERINE DAVIS-YOUNG: It’s still pretty early to be trying to draw conclusions about why it’s so much higher this year. But high temperatures are obviously part of the picture. ... Especially because we did have this really early start to the heat season. We talked about this really intense March heat wave we had. So there were at least nine heat-related deaths in the month of March, which is unprecedented. I’ve gone back through several years of records in Maricopa County. There’s only ever been like one heat-related death in March before. So that was a big change this year.

Another factor that experts say makes heat more deadly is when you have these really long periods of intense heat and it never cools off at night. So you think about 115 during the day, 95 at night. Those kind of temperatures, day in and day out, especially for unsheltered people who can’t escape the heat, that becomes really dangerous.

So you might think back to the summer of 2023. We had this extreme heat warning in effect basically the whole month of July. That was a record 29-day long extreme heat warning from the National Weather Service. Well, this summer we actually had the second-longest extreme heat warning ever, which was 18 days from the end of July into early August. So when I spoke to the medical examiner, he tells me his office saw a similar surge in deaths during those two events in 2023 ... and this summer. And it’s worth noting that climate change is making these longer and more intense heat waves much more likely. So climate scientists say that Phoenix can expect a lot more of that, unfortunately, in the future.

MARK BRODIE: Well, so a lot of cities and the county have put a lot of investment into trying to reduce heat deaths and keep people safe, cooling centers, things like that. Do we have a sense of whether or not those services are being used and to what extent?

KATHERINE DAVIS-YOUNG: Yeah, so data from the city of Phoenix is showing that the city’s extended hour cooling centers have had more than 45,000 visits this summer, which is more than twice what they had seen around the same time last year. And other charitable organizations I’ve talked to are also reporting that they’ve stayed really busy. So that shows the demand is definitely there with these hotter temperatures.

There may also be higher levels of need this year. We know there have been cuts to the SNAP program, gas prices are much higher, energy costs are higher this year. So these really low-income families are feeling the financial pinch more potentially this year. We do know that a lot of heat-related deaths happen when you have, say, someone who can’t afford to run their air conditioner all day, or someone who can’t afford to fix it when it breaks. So that may be part of the issue as well.

MARK BRODIE: OK, so Katie, before I let you go, I mentioned it’s finally September. We all know temperatures in the low to mid-100s. Any sense of when we’re going to get some relief from these high temperatures?

KATHERINE DAVIS-YOUNG: Typically, Phoenix’s last 100-degree day is Oct. 5. In recent years, it’s been later October. Long-range forecasts right now from the National Weather Service are showing Arizona’s leaning toward above-normal temperatures for fall.

MARK BRODIE: All right. Something to not look forward to, I suppose. That is KJZZ’s Katherine Davis-Young. Katie, thanks so much.

KATHERINE DAVIS-YOUNG: Thank you.