WEATHER

Until next year: As fall makes its debut, here's a look at how summer impacted Arizona

Kye Graves
Arizona Republic

Autumn is right around the corner as metro Phoenix's 2023 summer experience officially ends Friday night.

For nearly three months each year, from mid-late June to mid-late September, those in the Phoenix area and throughout Arizona endure a rigorous test of strength and poise as temperatures skyrocket.

The blistering heat coincides with the state's typical monsoon season, though, usually offering at least a chance of a reprieve from the oven, as well as providing a breathtaking show of nature's force.

Typically.

2023, however, was something else entirely.

Phoenix's unforgiving summer has produced record-setting daily temperatures in both the high and low categories, streaks of days above 110-plus degrees, nights barely dipping below 95, and a monsoon that is on pace to be the driest ever.

And while the heat will remain as fall makes its debut in Arizona, here's what this summer brought us.

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Phoenix sees 55 days at or above 110 degrees

Five days after the summer solstice, on June 25, the Valley saw its first 110-degree day of the year, according to the National Weather Service.

Looking at the data, this was a very late start for Phoenix, where the average first day of 110 usually hits around June 8. In itself, this was almost a record, as the latest day Phoenix has ever reached 110 was on June 28, 2009.

Little did we know it was just the beginning.

From that point on and through the span of summer, Phoenix would add 54 more days at or above 110 degrees to its tally — more than half of it coming during the month of July — and ultimately, on Sept. 9, surpassed the previous set back in 2020 at 53 days.

Phoenix could still add to this total.

Maricopa County heat deaths surpass 2022 total

So far, more than 200 people throughout Maricopa County have died in heat-related/associated deaths, according to the Maricopa County Department of Public Health, with the brunt of it heavily impacting unhoused communities.

This year's total sits at 202 confirmed heat-related or associated as of Sept. 9, with 356 cases still under investigation. Data shows that 103 of the confirmed deaths were heat-caused, while 99 were heat-related.

As of Sept. 12, there were 51 indoor heat-associated deaths reported, the county said. Nearly 29% of all confirmed reports affect those from 50 to 64 years old, followed by 21% at 35-49, 20% at 65-74, 15% at 75-plus, 13% for 20-34 and 1% at ages 5-19.

The cumulative number of deaths was 175 for 2022, with 238 still being looked at.

The first reported casualty for 2023 was reported on April 11, the Department of Public Health stated in its report.

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Metro Phoenix bakes for 31 straight days at or above 110 degrees

June 30 to July 30: During this timeframe, the Phoenix area never relinquished its grip on peak temperatures, going 31 consecutive days at or above 110 degrees.

The longstanding original record, previously set in 1974, lasted only 18 days.

In addition, the Valley had two days in a row with a high of 119 — three for the month — on July 19 and 20, and a third on July 25. For each of these scorchers, 119 eclipsed the prior record daily highs for those dates.

Phoenix sets 25 new daily warm-low temperatures, 21 daily highs

A big part of this summer's overall ferocity was seen in the strength of its low temperatures.

The extreme heat was nothing short of, well, extreme. While Phoenix added 21 new daily high temperatures through the months of July, August and September, 25 new daily warm lows are nothing to scoff at either.

The Valley witnessed 16 straight days of low temperatures at or above 90 degrees, ending on July 25. The 16-day streak more than doubled the preceding mark of seven days, which had only been tied on multiple different occasions until 2023.

Minimum temperatures in the months of July and August were only south of 90 degrees for around half of the time, 13 and 15 days respectively.

New daily lows:

DateLow temperature
7/10, 8/791
7/21, 8/392
7/14, 7/20, 7/25, 7/28, 7/30, 8/2, 8/17, 8/28-3093
7/12, 7/16, 7/18, 7/2494
7/13, 7/17, 7/2995
7/2296
7/1997
Data taken from Phoenix area NOWData - NOAA Online Weather Data Daily Almanac

New daily highs:

DateHigh temperature
9/8110
9/10113
7/13, 8/6, 8/27, 9/9114
7/29, 8/16115
7/14, 7/17, 7/24, 8/5, 8/29116
8/28117
7/15, 7/18, 7/22, 7/26118
7/19, 7/20, 7/25119
Data taken from Phoenix area NOWData - NOAA Online Weather Data Daily Almanac

Hottest July on record for Phoenix, second-hottest August

According to the weather service climate summary data, July in the Valley had an average high temperature of 114.7 degrees, 8.2 degrees above normal. The average temperature this year for the month was around 102.7, which was 7.2 degrees above its usual mean.

Additionally, July often sees just shy of one full inch of rain, per climate data ranging from 1991-2020.

Phoenix Sky Harbor International Airport got none this year.

2023 in short played host to the hottest July since 2020 which posted a standard temperature of 98.9.

August's story was relatively the same, generating the second-hottest month on record, behind 2020, with an average high temperature of 109.5 degrees and a total average of 98.8, each about 4.5 degrees above the norm.

Rainfall data in recent years showed that Sky Harbor receives around 0.93 inch of rain during the year's eighth month, but in 2023, only got 0.12.

The month did, however, take the top spot for the highest average low temperature at 88 degrees flat.

2023 monsoon 'almost certainly' to be driest on record

There are only eight days remaining in Arizona's uneventful monsoon, one that the weather service said will not be remembered.

"It'll almost certainly be the driest monsoon on record," meteorologist Mark O'Malley told The Arizona Republic. "At the airport, they only got 0.15 inch of rain."

The weather service records official weather data from Sky Harbor for the Valley, explaining the shallow reading compared to parts of the greater Phoenix area that have received much more rain throughout the course of the season.

If the airport doesn't receive at least 0.20 inch of rain come Sept. 30, this will have been the driest monsoon on record. Until then, the current record set in 1924 at 0.35 inch still stands.