The National Weather Service’s active heat alert count climbed back to 89 Sunday, up from 83 the previous day, with Florida rejoining the list a day after dropping off and Southern California emerging as a fresh hot spot alongside the ongoing Southern Plains and Gulf Coast heat.
Advisories and warnings now span 25 states and Puerto Rico — Alabama, Arkansas, California, Colorado, Florida, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Minnesota, Missouri, Mississippi, Montana, Nebraska, New Mexico, Nevada, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Utah and Wisconsin. That’s the same broad footprint as Saturday, but the six-alert increase shows the heat intensifying rather than retreating, with new advisories layering onto areas already under alert as Florida re-entered the list after a brief reprieve.
The clearest new signal is in Southern California, where the National Weather Service has posted advisories across San Diego, Orange, Riverside and San Bernardino counties. Inland valleys and mountains are forecast to see highs in the upper 80s to upper 90s, with the San Diego County Mountains reaching the mid to upper 90s and overnight lows staying in the upper 60s to low 70s — warm enough to limit overnight cooling and compound heat stress for a second straight day. Most of those advisories run until 8 p.m. PDT this evening. That marks a shift from earlier in the outbreak, which had centered on the Southern Plains and was pushing into the Gulf Coast and Southeast; the alert list now stretches coast to coast, from inland Southern California to the Upper Midwest and Puerto Rico.
Inland stretches of San Diego weather and the broader Riverside-San Bernardino corridor are among the areas facing the most persistent heat, while the Midwest contingent — Iowa, Illinois, Indiana, Kansas, Minnesota, Missouri, Nebraska, South Dakota and Wisconsin — keeps the alert map unusually wide for late July. The Wisconsin and Minnesota advisories in particular reflect the heat’s continued push into the Upper Midwest, a region not typically associated with extended advisories at this scale.
The National Weather Service’s standard guidance remains in force across the alert area: drink plenty of fluids, stay in an air-conditioned space, avoid direct sun exposure, and check on relatives and neighbors, particularly those without reliable air conditioning. With 89 alerts now active and the geographic spread holding near its widest point of the week, forecasters are watching whether the heat continues building in the Southwest even as it eases in isolated pockets elsewhere. Houston weather remains under advisory as the Gulf Coast heat that has persisted for days shows no clear sign of breaking.