Published: March 31, 2020
Based on 1981-2010 averages.
Although many may be looking forward to prolonged warmth when spring arrives, the average date of the last freeze varies greatly across the United States.
The last freeze of the season is used not only by gardeners, but also by anyone looking to finally pack away their winter coat for the season.
The map above illustrates when the last freeze of the season typically occurs, based on averages from 1981-2010 . Keep in mind that the last freeze can vary greatly from year to year depending on the country's weather pattern during the spring months.
Much of the South usually has its last freeze of the season before the end of March, while the higher elevations of the West may not see the last 32-degree temperature until late May or even June.
This year, most of the East and South have had well above-average temperatures in March, and many locations will likely end up with a top-five-warmest March, according to data from the Southeast Regional Climate Center. This trend of warmer temperatures in the South and East with cooler-than-average temperatures in the North and West will likely continue into April. This suggests that many areas of the Lower 48 may not have a late last freeze, but a spring cold blast can occur even in an overall warm spring.
(MORE: April Temperature Outlook)
Let's dig deeper into when specific regions and cities can expect the season's average final freeze.
Before March 10
Cities along the Gulf Coast and in the Deep South have their average last freeze before March 10. This can occur much earlier or much later depending on the weather conditions each year.
Since 1950, Miami has only recorded five winter seasons with a freeze: 1976-77, 1979-80, 1980-81, 1984-85 and 1989-90.
The map at the top of this article also shows an area in the Desert Southwest and Southern California that has its average last freeze before March 10. This includes Los Angeles and San Diego, but these cities don't typically have freezing temperatures.
Since 1950, San Diego has only dropped to 32 degrees or colder one time (Jan. 13, 1963) at Lindbergh Field. Los Angeles International Airport dropped to the freezing mark or colder the same date as San Diego and also on Dec. 21, 1968.
March 10-30
A large part of the South, along with parts of the Interstate 95 corridor, Desert Southwest and West Coast, typically experience their last freeze between March 10 and March 30.
Chilly spring conditions have pushed the last freeze of the season to as late as April or even early May. Atlanta has experienced its last freeze of the season as late as April. However, freezing temperatures in late April last occured in 1986.
March 30-April 10
A broad area from southern New Mexico to the Northeast urban heat islands typically experiences its last freeze of the season in late March or early April.
It is interesting to note Boston's latest last freeze is earlier than Raleigh, North Carolina's, by a week and a half, likely due to Boston's proximity to the relatively warmer Atlantic Ocean.
April 10-30
Many cities from the Plains and Midwest to the East Coast have their average last freeze in mid to late April in an average year.
If you live in any of these cities, despite your average final freeze in mid- to late April, it may be best to wait until closer to Memorial Day to plant your garden. In Chicago, the last freeze occurred as late as May 25 in 1992, which was Memorial Day that year.
April 30-May 20
Average last freeze dates in early to mid-May are basically confined to the nation's northern tier and Mountain West.
Despite these cities having their last freeze in early to mid-May in an average year, sometimes it doesn't occur until around or after the summer solstice (June 20 this year), such as in Fargo, North Dakota; Concord, New Hampshire; and Reno, Nevada.
After May 20
Any freezes after May 20 typically occur in areas near the Canadian border or in the highest elevations of the Rocky Mountains.
The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
The Weather Company’s primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
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