Phoenix’s heat continues to break records. As of Thursday, the city has endured an 81-day streak of temperatures reaching 100 degrees or higher, surpassing the previous record of 76 days set in August 1993.

This summer, the city has seen numerous record-breaking temperatures, surpassing previous highs by up to 3 degrees—both during the day and at midnight.

Many of these records are not coming from high temperatures but from record-breaking warm low temperatures.

This summer recorded 33 days with low temperatures at or above 90 degrees—a level that was virtually unheard of before the 1980s, according to the National Weather Service.

90-degree nights:Why is Phoenix experiencing so many record-breaking warm low temperatures?

Warm Nights

These warm nights in the Valley have become increasingly common in southern regions of the U.S. The weather service has cited high moisture in the atmosphere as a contributor to these temperatures, as well as urbanization.

Paved surfaces, concrete asphalt, and buildings retain heat from the daytime, making it harder for areas in metro Phoenix to cool down overnight.

These factors contributed to another milestone: thehottest June ever recorded in Phoenix, with an average temperature of 97 degrees. The previous record, set in 2021, had an average temperature of 95.3 degrees.

What other records have been broken this summer? Here’s what to know.

Summer nights:90-degree lows, once rare, are now common in Phoenix. Are 100-degree lows next?

Record-breaking high temperatures

2024 set four records for hottest days in the Valley:

• The high for June 6 was 113 degrees, breaking the previous record in 2016 at 111 degrees.
• On July 5, temperatures soared to 118 degrees, surpassing the previous record of 116 degrees set in 1983.
• The 118-degree temperature on July 8 broke the previous record of 115 degrees set in 1985.
• On August 3, temperatures reached a high of 116 degrees, surpassing the 2020 record by 2 degrees.

June’s record-breaking warmest low temps

This summer shattered the record for the most warm nights with lows above 90 degrees between June 1 and July 11, more than doubling the previous mark.

In 2024, Phoenix experienced 16 nights with lows above 90 degrees, compared to the previous record of seven nights in 2021.

Late June saw a record-breaking three-night streak of the warmest low temperatures from June 21-23:

• On June 21, the low temperature hit 92 degrees, surpassing the previous record of 90 degrees set in 2017.
• June 22 also recorded a low of 92 degrees, edging out the 2017 record by 1 degree.
• On June 23, the low reached 91 degrees, breaking the 2016 record of 89 degrees.

This year, June 27 set a new record for the all-time warmest night in June with a low of 95 degrees, surpassing the previous record of 93 degrees set in 1990.

Record-breaking warm lows in July and August

Nighttime temperatures usually sat in the high 80s, with some nights breaking through the 90-degree barrier. Here are some of the hottest:

• On July 2, the low temperature of 92 degrees broke the previous record of 90 degrees set in 2010.
• July 3 saw a low of 93 degrees, surpassing the record set in 2001.
• On July 5, the low of 93 degrees exceeded the 91-degree record from 1996.
• July 7 recorded a low of 92 degrees, breaking the 2018 record.
• July 10 also had a low of 92 degrees, surpassing the previous year’s record by 1 degree.
• August 4 experienced a low of 93 degrees, the warmest since 2018.
• August 10 recorded a warm low of 93 degrees, surpassing the 92-degree record set in 1995.

What does this mean for people living in Phoenix?

High temperatures, both during the day and at night, can make individuals susceptible to heat-related illnesses, which can be life-threatening.

The Maricopa County Department of Public Health warns that people aged 50 and older, those experiencing homelessness, or individuals with a history of physical or mental health issues are particularly at risk for heat-related illness or death.

To stay safe in extreme heat, the Arizona Department of Health recommends limiting outdoor activities, wearing loose clothing, and drinking two to four cups of water every hour while working outside.

On days of extreme heat, the weather service advises residents to check on their neighbors, take necessary heat precautions, stay hydrated, and seek out shade and air-conditioned spaces.

In 2024, the Maricopa County Department of Public Health confirmed 96 heat-related deaths, with an additional 462 cases under investigation.

Metro Phoenix has over 100 cooling centers available. For information, contact the Arizona Department of Health Services at 602-364-3118 or visit an air-conditioned cooling center in your area. To locate one, go to maricopa.gov.