Updated Aug 1, 2023 - Energy & Climate
Phoenix is first U.S. city with a monthly temperature above 100°F
Add Axios as your preferred source to
see more of our stories on Google.


Phoenix in July became the first major city in the country to reach an average monthly temperature higher than 100°F.
By the numbers: Phoenix's average July temperature of 102.7°F marked its hottest month on record, shattering the previous record of 99.1°F in August 2020.
- The city saw a record 19 days with overnight minimum temperatures at or above 90°F, an all-time record high minimum temperature of 97°F, and a record-setting 17 days with highs at or above 115°F, according to the National Weather Service forecast office in Phoenix.
- Phoenix also experienced its longest streak of days with a high temperature 110°F or above, with 31. This beat the old record of 18 straight days.
The intrigue: Usually temperature records are broken by fractions of a degree.
- The next nine hottest months in the Valley were separated by only 2.3 degrees.
- Smashing a monthly record by nearly 4°F is unheard of, let alone doing so while establishing another all-time milestone.
Between the lines: Climate scientists say Phoenix's heat record demonstrates the loaded climate dice due to human-caused climate change, with the odds increasingly favoring extreme events.
- Climate change is also tied to longer, more extreme heat waves globally.
- A recent study found the Southwest heat wave, which is continuing this week, would have been "virtually impossible" in the absence of human-caused climate change.
Go deeper:
What this summer's weather reveals about climate change

