Updated Aug 1, 2023 - Energy & Environment
Phoenix is first U.S. city with a monthly temperature above 100°F
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