A sudden drop in temperatures is forecast for four states in the central US, prompting meteorologists to issue a series of freeze warnings on Monday.

Meteorologists with the National Weather Service (NWS) issued freeze warnings for seven states on Monday, with some of those states expecting temperatures of up to 30 degrees for hours overnight.

Missouri, Nebraska, Kansas and South Dakota are the states expected to see the largest temperature drops. During the day on Monday, temperatures in each of these regions were in the upper 50s and low 60s, with the overnight forecast calling for temperatures to drop to as low as 20°C. Most frost warnings were expected to come into effect during the overnight hours.

NWS meteorologist Michael Connelly said Newsweek that such low temperatures are “very common” in the Aberdeen, South Dakota region this time of year.

“We are near the normal end of the growing season,” he said.

Temperatures are expected to rise again in some of the affected areas on Wednesday.

“Autumn is a season full of ups and downs! Expect another hard freeze tonight and a chilly start to the week before temperatures rise above normal again,” the NWS office in Aberdeen, South Dakota, wrote on X, formerly Twitter. “With strong southerly winds, these warmer temperatures pose an increased risk of fire.”

There were also freeze warnings in Minnesota, North Dakota and Michigan. Temperatures were expected to fall by 20 to 25 degrees overnight.

“Frost and freeze conditions could kill crops and other sensitive vegetation and potentially damage unprotected outdoor utilities,” the NWS freeze warning states. “Take steps now to protect sensitive plants from the cold. To prevent water pipes from freezing, wrap them, drain them, or drain them slowly.”

In addition to the freeze warnings, NWS meteorologists issued several other cold weather warnings.

The NWS offices in Illinois, Maryland, Wisconsin, Pennsylvania, Nebraska, Iowa, Kansas and Missouri have issued a lockdown warning. NWS offices in Pennsylvania, Arkansas, Missouri, South Carolina, Maryland, Wisconsin, Iowa and Illinois also issued a freeze warning.

Frost occurs when temperatures are so cold that dew freezes into ice. Temperatures must be 32 degrees or below, but frost can form even when outside temperatures are above freezing, as temperatures near the ground can be up to 10 degrees colder.

The chilly temperatures come as AccuWeather releases its 2024-2025 winter forecast for the United States. Much of the U.S., including the central, southern and eastern regions, is expected to experience slightly above normal winter temperatures.

Below average temperatures are forecast for the Northwest, including Oregon, Washington, Idaho, Montana and Wyoming. This winter is also expected to bring several atmospheric rivers to the West Coast, particularly California.