About 25 million people in the United States are under a freeze alert

(CNN) — Frost warnings across much of the southeastern United States have been updated to include freeze warnings by local National Weather Service (NWS) offices, stretching from Texas to North Carolina.

The warnings now cover nearly 25 million people and stretch from Longview, Texas to Sanford, North Carolina.

Freeze warnings will go into effect this Monday night and last until Tuesday morning.

Frost watches and advisories have also been issued further south for parts of Louisiana, Mississippi, Alabama and Georgia.

crop damage

Temperatures across the southeastern United States will be below normal for this time of year on Tuesday morning. Temperatures are expected to drop between -6°C and -1°C Tuesday morning in Atlanta, Charlotte and Birmingham, Alabama, posing a threat to crops.

“Snow and freezing conditions will kill crops and other sensitive vegetation and possibly damage unprotected outdoor pipes,” warns the Peachtree City, Georgia, NWS office.

Sheltering plants indoors is the easiest way to protect them from hard frosts, but if you can’t, covering them can also help.

For the farmer, recovering his harvest can be a bit more difficult.

Fruits and trees have been blooming for a few weeks as the warmest winter on record in the United States ends. An exceptionally warm winter sends premature signals to crops to germinate early. When frost arrives in time in March, these crops are exposed and unprotected, leaving them vulnerable to frost damage and freezing.

Farmers need to use tarps, irrigation and large fans to cover their crops as much as possible to prevent damage.

Because of this cold snap, cities in the Midwest, South, and East Coast will experience normal January and February temperatures, rather than the temperatures typically experienced in early March.

St. Louis could see a swing of more than 6 degrees from 15 degrees Celsius on Saturday to 4 degrees Celsius this Monday. Atlanta’s high temperature could drop as much as 10 degrees Saturday through Monday: 21°C to about 10°C.

These temperatures may not be freezing, but are more typical of mid-winter in some parts of the South.

Memphis, Tennessee, and Huntsville, Alabama are forecast to see a high of 10°C on Monday, a typical mid-January high.

Philadelphia’s high temperature on Tuesday is expected to be 7°C, its average high for February 19.