Millions are currently under heat advisories in the South, facing potentially hazardous temperatures. Meanwhile, five states have issued frost advisories, reminding residents of the approaching first hard freeze of the season.
Heat Advisories Across the South
Parts of Texas, Oklahoma, Kansas, Louisiana, Arkansas, Missouri, Illinois, Indiana, Kentucky, Tennessee, Alabama, and Mississippi are experiencing heat advisories. A trend throughout the summer has been the occurrence of some of the warmest recorded temperatures in these areas.
The National Weather Service’s (NWS) Climate Prediction Center predicts above-average temperatures for nearly the entire U.S. through late September. However, few regions are seeing signs of cooler weather already.
Frost Advisories Issued
On Tuesday, NWS offices in Pocatello, Idaho; Gray, Maine; and Burlington, Vermont, have issued frost advisories. Temperatures may dip into the low 30s. This marks the first advisory of the season for these offices.
NWS meteorologist Cameron Barker in Maine expects more frost advisories in the coming weeks. Historical data from the National Centers for Environmental Information (NCEI) shows that these temperatures align with climate normals.
Understanding Freeze Dates
Average first freeze dates can be as early as August 31 in some areas. Northern states are more likely to see the first freeze earlier, while high-altitude regions of southern states also have earlier averages. Freeze dates can vary due to elevation differences.
Frost formation is possible even when air temperatures stay above freezing. The NWS states that the ground temperature can be 5 degrees cooler than the air due to radiational cooling.
Alerts and Warnings Explained
The NWS provides various alerts regarding cold temperatures. A frost advisory covers Idaho, New York, New Hampshire, Vermont, and Maine, with air temperatures between 33 and 36 degrees. Severe freeze warnings occur when freezing temperatures are widespread and significant.
During the frost advisory, temperatures in Maine could reach 33 degrees in Oxford County. New Hampshire’s Coos County and Essex County in Vermont are similarly affected. In New York, the advisory applies to Essex, Franklin, and Clinton counties.
Idaho’s advisory takes effect at 3 a.m. Tuesday until 9 a.m., affecting areas like St. Anthony, Shelley, and Idaho Falls. Temperatures could drop to 34 degrees.