Cities That Hit or Topped 100 Degrees for the First Time Ever

July 2026 was the warmest month in the history of the continental United States. According to the National Oceanic and Atmospheric Administration, the average temperature in the Lower 48 was 76.9°F, one-tenth of a degree higher than the previous record, set in July 1936 during the Dust Bowl, and 3.3°F higher than the average July temperature during the 20th century. 

Last month’s record-breaking heat was driven by several heat dome events in which slow moving high pressure systems fueled a prolonged stretch of dangerously high temperatures. Local weather station data compiled by NOAA shows that daily record-highs were either matched or broken more than 3,300 times last month, as heat domes impacted tens of millions of Americans, from the Western and Rocky Mountain regions, to the South and up through the Northeast. 

In addition to record daily highs in cities and towns across the country, many communities also reported new all-time record highs. Throughout July 2026, local weather stations reported never before seen temperatures on 107 occasions. In several of these cases, the mercury either hit or exceeded 100°F for the first time in history.

Using data from NOAA’s Daily Weather Records program, Climate Crisis 247 identified the places where temperatures matched or topped 100 degrees for the first time ever. We reviewed temperature readings for all U.S. weather stations reporting all-time record heat in July 2026, and identified those in which new record highs either hit or exceeded 100°F for the first time ever. Places are ranked on the difference between the new triple-digit record high, and the highest-recorded temperature before 2026. All supplemental data is also from NOAA. 

The places on this list are concentrated in the Rocky Mountain region. Montana, Utah, and Idaho are each host to two weather stations that reported temperatures at or above the 100-degree threshold for the first time ever in July 2026. Other weather stations on this list include one in Colorado and another in Idaho. The remaining two weather stations are in Florida and Michigan. 

10. Livingston, Montana

• New all-time record high temperature: 100°F on July 12, 2026
• Pre-2026 all-time record high temperature: 99°F on July 13, 2005
• Average local summer temperature: 64.1°F (78.7°F daily high)
• Reporting weather station: Livingston 12 S, MT Weather Station

9. Bern, Idaho

• New all-time record high temperature: 101°F on July 13, 2026
• Pre-2026 all-time record high temperature: 100°F on July 23, 2003
• Average local summer temperature: 62.3°F (81.0°F daily high)
• Reporting weather station: Bern, ID Weather Station

8. Amasa, Michigan

• New all-time record high temperature: 100°F on July 14, 2026
• Pre-2026 all-time record high temperature: 98°F on July 16, 2006
• Average local summer temperature: 62.4°F (76.2°F daily high)
• Reporting weather station: Amasa 1 W, MI Weather Station

7. Fort Lauderdale Beach, Florida

• New all-time record high temperature: 101°F on July 31, 2026
• Pre-2026 all-time record high temperature: 99°F on August 23, 2025
• Average local summer temperature: 83.2°F (90.0°F daily high)
• Reporting weather station: Fort Lauderdale Beach, FL Weather Station

6. Gypsum, Colorado

• New all-time record high temperature: 102°F on July 20, 2026
• Pre-2026 all-time record high temperature: 100°F on July 13, 2005
• Average local summer temperature: N/A
• Reporting weather station: Gypsum Colorado, CO Weather Station

5. Bountiful, Utah

• New all-time record high temperature: 102°F on July 12, 2026
• Pre-2026 all-time record high temperature: 100°F on July 13, 2002
• Average local summer temperature: 72.8°F (82.8°F daily high)
• Reporting weather station: Bountiful Bench, UT Weather Station

4. Buffalo Ridge, Wyoming

• New all-time record high temperature: 103°F on July 11, 2026
• Pre-2026 all-time record high temperature: 100°F on July 28, 2021
• Average local summer temperature: 66.0°F (78.4°F daily high)
• Reporting weather station: Buffalo Bill Dam, WY Weather Station

3. Randolph, Utah

• New all-time record high temperature: 100°F, 101°F, and 103°F on July 7th, 28th, and 20th, 2026
• Pre-2026 all-time record high temperature: 97°F on August 22, 2025
• Average local summer temperature: 60.5°F (78.2°F daily high)
• Reporting weather station: Randolph, UT Weather Station

2. Melville, Montana

• New all-time record high temperature: 101°F on July 12, 2026
• Pre-2026 all-time record high temperature: 95°F on July 12, 2002
• Average local summer temperature: 58.6°F (72.4°F daily high)
• Reporting weather station: Melville 4 W, MT Weather Station

1. Lewis Lake Divide, Wyoming

• New all-time record high temperature: 102°F on July 24, 2026
• Pre-2026 all-time record high temperature: 93°F on July 31, 1989
• Average local summer temperature: N/A
• Reporting weather station: Lewis Lake Divide, WY Weather Station