Discussion: The stress on the public and infrastructure of the summer 2023 heat across the Gulf States was immense. And ideal source region for heat elsewhere, the U.S. ranked 3rd hottest in the 129-year climatology for JUL/AUG/SEP 2023 (Fig. 1). During that 3-month period, New Mexico, Texas, Louisiana, and Florida observed their hottest mid-to-late summer on record. Many other states in the Interior West and Northeast observed top-10 all-time hot JUL/AUG/SEP including record warm in Maine. Only the Ohio to Tennessee Valley was temperate.
Mid-to-late summer 2023 precipitation varied widely across the U.S. and featured extremes (Fig. 2). Each state in New England ranked 2nd or 3rd wettest on record while New Mexico to Mississippi were each in the top 8 driest of 129 years including 2nd driest for Louisiana. Nevada was in the top 7 wettest on record while the Upper Midwest was dry.
The last month of calendar warm season ranked 7th hottest in the 129-year climatology. Once again, the hot signature was inspired by record heat in New Mexico and Texas (Fig. 3). Eleven states ranked in the top 10 hottest months of September on record including near records in Minnesota and Vermont. In September, the Southeast and West were temperate.
September 2023 ranked 22nd driest on record. Wide variation in state precipitation ranks were observed (Fig. 4). The dry zone stretched from Mississippi to Michigan and coupled with anomalous warm climate helped to inspire the low water on the Mississippi River. Ohio observed the 5th driest September on record. Nevada and the northern Mid-Atlantic States were the wet spots in September including the 3rd wettest September on record in Connecticut.
Fig. 1: July through September 2023 state temperature ranks by NOAA for the 1895-2023 climatology.
Fig. 2: July through September 2023 state precipitation ranks by NOAA for the 1895-2023 climatology.
Fig. 3: September 2023 state temperature ranks by NOAA for the 1895-2023 climatology.
Fig. 4: September 2023 state precipitation ranks by NOAA for the 1895-2023 climatology.