September was one of the warmest ever in the United States, with records falling in 111 counties, but conditions were moderate in Southern California.
Most of the country baked under record heat in September as large swaths of hot air covered the Midwest and East. The final tally put September 2023 as the seventh warmest in the last 129 years.
The National Oceanic and Atmospheric Association (NOAA) said it was also the third-driest September ever recorded in the lower 48 states.
NOAA found the warmer-than-usual conditions will likely continue through winter.
“With the combination of multiple months of being above normal temperatures, mixed in as we’re sort of starting to push into this El Niño season, we’re starting to see a lot of continuous states and locations — geographies of the United States — kind of maintain this record warmth that we're seeing,” said Rocky Bilotta, a physical scientist at NOAA.
The extended heatwave in the Midwest became the 24th weather related disaster in 2023 to cause $1 billion in damages.
Most of those events were linked to storms which brought hail, tornados and thunderstorms.
The total cost of those disasters topped $67 billion.
Notable September weather events included a bomb cyclone that brought heavy rain to the Pacific Northwest and Tropical Storm Ophelia which made land in North Carolina and moved north.
Southern California bucked the national trend last month, recording average or below-average temperatures. But the region is facing an uncertain outlook this winter.
That is in large part because of the warming ocean waters in the central and eastern Pacific.
“It is going to be a stronger El Niño and that’s usually associated with warmer global temperatures and then when the atmosphere can hold more water it can, that heat can draw more moisture out of the soils,” Bilotta said.
Drought conditions moderated in California last month with less than 5% of the state considered to have drier than normal conditions.
Officials at the U.S. Drought Monitor said that is because this year’s rain has refilled most of the state’s reservoirs.
