St. Louis just closed out the longest stretch of 90-degree weather the city has ever recorded, with 192 days separating its first hot day of the year from its last. The streak broke a record that had stood since 1950, and it capped a September that turned out to be the warmest the city has ever measured.
St. Louis first hit 90 degrees on March 22 this year, according to Fox 2 Now. The March 22-to-September 30 span amounted to 192 elapsed days, breaking the previous record of 189 days, which ran from April 23 to October 30, 1950, as Vandalia Radio reported. FOX 2 Now had already reported the milestone on October 1, before the St. Louis Public Radio story appeared on October 2.
September Smashed the Old Heat Marks
September 2026 turned out to be St. Louis's warmest September on record, with an average temperature of 78.4 degrees, per the station's reporting. The month produced three record high temperatures and six record warmest overnight lows, and the city went without a single below-normal average temperature day until Sept. 22. The previous warmest-September record dated to 2019.
The persistent warmth meant the city spent nearly the entire month running hot before conditions finally eased late in September. A heat advisory that the National Weather Service issued and allowed to expire on Sept. 19 was the latest such advisory the agency had put out in more than 20 years, the same report noted. Jayson Gosselin, a meteorologist with the National Weather Service in St. Louis, is cited in that coverage discussing the season's numbers.
Climate Central Ties Some Days to Climate Change
Climate Central's Climate Shift Index found that the influence of climate change was detectable in St. Louis's temperatures for 14 days in September, the station's report said. Separately, Climate Central also highlighted climate change's influence on St. Louis temperatures.
Climate Central's broader local data show average annual temperatures in St. Louis have risen 4.4 degrees Fahrenheit since 1970, with average fall temperatures up 3.9 degrees over the same period. The city has also logged 28 fewer days below freezing each year since 1970, and its annual precipitation has grown by 8.7 inches, with hourly rainfall intensity up 23 percent, according to the organization's figures.
Other Cities Saw Their Own Streaks
St. Louis wasn't alone in logging an unusual stretch of heat this year. Chattanooga, Tennessee, recorded 45 consecutive days with highs of at least 90 degrees, the longest such streak in records dating back to 1879, according to the Chattanooga Times Free Press. That topped the city's previous mark of 38 consecutive days, set in 1993.
For St. Louis residents who just lived through nearly 200 days bookended by 90-degree readings, the numbers add context to a season that already felt unusually long.
