Finally autumn: millions of people can expect the coldest air in months

CNN
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A dramatic pattern shift is bringing the coldest air since the spring to millions of people in the central and eastern United States, wreaking havoc on areas that have previously struggled to shed sustained heat feel more like November than October.

Since the season began last month, much of the country has found it difficult to experience extended fall cold spells. But the combination of an extended cold front and an impending blast of cold Canadian air will change that and temperatures could drop to 10 to 15 In the middle of the week the temperatures are below average.

As of Tuesday morning, more than 60 million people from the Plains to the Appalachians and the Northeast are under some type of freeze or freeze alert as temperatures plummet.

The first aspect of this cooling – a widespread cold front – began over the weekend. This cold front swept from the north-central U.S. through the eastern half of the U.S. on Monday, triggering a real fall chill for some along the way. Even cooler air from Canada will be pushed much further south on Tuesday and Wednesday.

Tuesday could be the coldest day of the week in Chicago, where the high temperature would struggle to reach 50 degrees. Before Monday's high of 57°C, Chicago had not recorded a high above 50°C since April.

Many areas outside the Midwest will see temperatures drop again on Wednesday. Wednesday is expected to be the coolest day since spring for millions, and in many places it will feel more like late November than October.

“True fall weather is forecast through the start of the weekend,” the National Weather Service in Atlanta said Monday.

The maximum temperature in Washington, DC, could peak at over 50 degrees on Wednesday – 10 to 15 degrees lower than normal for mid-October.

Atlanta could struggle to break out of the low 60s on Wednesday and stay in the 60s through Friday. The city hasn't recorded high temperatures below 70 degrees since May, and highs typically hover around 75 degrees this time of year.

Wednesday will also be the coolest day of the week for much of the Northeast, with highs in the 40s and 50s. Because daytime temperatures are so cool, there is a chance that temperatures could drop below freezing overnight. Given the cold, a few flurries could dust the highest elevations from West Virginia to New York and New England Tuesday evening.

“Frosty and freezing conditions are likely for several nights and in many areas this week,” the National Weather Service in State College, Pennsylvania, warned Monday.

Frost and freeze warnings are active for millions of people this week and more could be issued in the coming days.

Frost can cause plants not exposed to cold to die or can end the growing season of some regional staple crops. These conditions are also dangerous for people who do not have access to adequate heating.

Temperatures around freezing or near freezing are possible every night Tuesday through Thursday in western North Carolina, which was devastated by Helene late last month.

By the end of this week, temperatures will return to more typical October conditions across much of the central US and Northeast. Areas farther south, such as the southern Appalachians and the Southeast, will see cold temperatures persist through at least Friday.

By Saturday, seasonal highs in the 70s and 80s will return to the Southeast, while the 60s and 70s will spread north into the Midwest and parts of the Northeast.