September’s Record-Breaking Weather Roundup
Last Updated: 10/15/26
September 2026 was the warmest September on record for the contiguous U.S. (CONUS) and the second-warmest for the planet. 2026 had the warmest January through September period on record for the CONUS. September 2026 featured record-breaking heat in central states and severe weather, including tornadoes, across the Great Lakes, Hawai’i, and Puerto Rico. A rare late-September Nor’easter hit the Northeast, causing coastal flooding, power outages, and one death.
Heat
- Globally, September 2026 was the second-hottest September on record.
- According to NCEI’s statistical analysis, there is a greater than 99.9% chance that 2026 will rank among the three warmest years on record.
- September 2026 was the contiguous United States’ (CONUS) warmest September on record, with an average temperature of 69.42°F.
- Four months in 2026 to date—March, July, August, and September—ranked as the warmest on record for their respective months.
- January through September 2026 ranked as the warmest January-September period on record for the contiguous U.S.
- Four states recorded their warmest average September maximum temperatures on record: Arkansas, Louisiana, Oklahoma, and Texas.
- Fourteen states had their warmest average September minimum temperatures on record, and more than half of the states had average nighttime temperatures more than 5°F above the 20th-century average.
- Minimum temperatures in Kansas and Nebraska were more than 10°F above average.
- An estimated 80 million people experienced their warmest September minimum temperatures on record.
- The CONUS temperature-related energy demand during September was 286% of average and the highest value on record.
- Warm extremes in maximum temperatures spanned 83% of the CONUS, the second-largest extent on record, while warm extremes in minimum temperatures covered 84% of the CONUS, the largest extent on record.
- From September 1st through 30th, 2026, 2,243 daily maximum temperature records were broken, and 1,248 were tied in the U.S.
- From September 1st through 30th, 2026, 4,936 daily minimum temperature records were broken, and 2,502 were tied in the U.S.
Local And Regional Heat Records
- Illinois and Indiana: September 1–4 was the warmest start to September on record in Chicago and Rockford, Illinois, with four-day average temperatures of 85.4°F and 82.5°F, respectively. Afternoon heat indices reached 100–110°F across much of northern Illinois and northwestern Indiana on all four days.
- Kansas: Wichita reached 100°F on 10 days in September, setting a record for the most 100°F days in the month.
- Tennessee: Prolonged heat in mid-September set records across central Tennessee, including Nashville’s warmest two-week period in September on record.
- Illinois: On September 3rd, Casey, Illinois reached 103°F, its highest temperature on record.
- Illinois: On September 3rd, Morrisonville, Illinois reached 103°F, its highest temperature on record.
Cold
- From September 1st through 30th, 2026, 208 lowest daily minimum temperature records were broken and 138 were tied in the U.S.
Local And Regional Cold Records
- Oregon: An early-September cold spell brought Crater Lake National Park an average daily maximum of just 40.3°F during September 3–5, its coldest three-day period during the first week of September on record (1919–present).
Precipitation And Severe Weather
- The Southwest received more than twice its average September precipitation, with Arizona and New Mexico each recording their second-wettest September.
- Arizona received 2.97 inches (251.7% of average), its wettest September since 1983, while New Mexico received more than 5 inches (303.6% of average), its wettest since 1941.
- From September 1st through 30th, 2026, 2,135 daily highest precipitation records were broken and 261 were tied in the U.S.
Local And Regional Precipitation And Severe Weather Records
- Alaska: Heavy late-summer rainfall pushed some Interior Alaska rivers to record-high flows for so late in the season, including the Kuskokwim River near McGrath.
- Alaska: A late-September Bering Sea storm brought hurricane-force wind gusts to western Alaska, reaching 84 mph at Cold Bay and 86 mph at Cape Newenham.
- Hawaiʻi: On September 7–8, Hurricane Lowell passed west of Niʻihau as a Category 2 storm, producing 21.11 inches of rain at Kilohana and damaging winds. Power outages affected more than 90% of Kauaʻi.
- Iowa and Illinois: Multiple rounds of thunderstorms on September 19–20 dropped 2–6 inches of rain along and north of the I-80 and Highway 30 corridors in eastern Iowa and western Illinois, producing flash flooding, road closures and moderate to major flood stages on area rivers.
- Michigan: Severe storms on September 2–3 produced an EF-2 tornado in Detroit, Michigan, the first confirmed tornado within city limits since July 1997.
- New Mexico: Heavy rainfall of 3–6 inches on September 22 triggered a Flash Flood Emergency in Mora County, while Albuquerque had its second-wettest September on record.
- Northeast: A rare late-September Nor’easter caused prolonged coastal flooding, with water levels at Ocean City, Maryland, rising above 5 feet relative to mean lower low water (MLLW) for the first time in nearly 14 years.
- The Nor’easter killed one person in New York and left approximately 130,000 people without power across the Northweast
- Pennsylvania and New York: Severe storms on September 1–2 produced tornadoes across Pennsylvania and New York, including an EF-2 with 115-mph winds in Seneca County, New York. On September 9, an EF-1 tornado with 105-mph winds occurred near Cyclone, Pennsylvania.
- Puerto Rico: Thunderstorms produced 2–3 inches of rain across parts of western Puerto Rico on September 19, prompting a Flash Flood Warning.
- South Dakota and Iowa: On September 1, severe storms produced 2.75-inch hail in southeastern South Dakota and 70–80+ mph wind gusts into northwestern Iowa.
Drought
- As of September 29th, about 59% of the contiguous U.S. was in drought, about the same percentage as at the beginning of September.
- In September, drought expanded or intensified over much of the southern Plains, Lower Mississippi and Tennessee valleys.
- As of September 29th, drought covered 89% of the South region, its largest extent since October 2000.
- Dry extremes covered 48% of the CONUS, ranking as the second-largest January–September extent on record.
Local And Regional Drought Records
- U.S. Virgin Islands: Drought worsened across the U.S. Virgin Islands in September, with St. Thomas reaching Exceptional Drought (D4) and water shortages and agricultural losses reported across the territory.
Wildfire
- In September 2026, 9,965 fires burned 365,439 acres across the U.S.
- This is the second-highest number of September fires since records began in 2001, and the highest number of September fires since 2010.
- From January through September 2026, 62,218 fires burned 8,603,723 acres across the U.S.