When Is The First Freeze Of Fall? It Ranges From September To November For Most Of US

F​all is when a majority of the United States sees its first freeze of the season, starting in higher elevations and the nation's northern tier in September before spreading southward through October and November.

W​hat is the first freeze? This is when the temperature reaches 32 degrees or lower for the first time in the colder months of the year. It's the threshold when unprotected plants can be damaged, especially if the temperature remains at or below freezing for multiple hours.

The timing of the first freeze depends on elevation and where you live. The map below shows the average date of the first freeze, using the latest 30-year period data (1991-2020) from NOAA.

The first 32-degree low temperatures are usually experienced before or right around the time fall officially begins in the higher elevations of the West and near the Canadian border.

By the end of October, the average first freeze has occurred from much of the Northeast into the Midwest and even northern parts of the South. First freezes are common in November from the coastal mid-Atlantic into much of the Deep South.

T​he warming influence of oceans and other bodies of water also skews the first freeze date later in these locales compared to slightly farther inland.

F​irst freeze timing can vary from year to year. Different weather patterns each year can make the first freeze occur earlier or later than the average shown for a given city or region. In fact, the earliest freeze on record for the selection of cities below occurred nearly a month or more before the average date.

Frost can damage vegetation at temperatures above freezing and a killing freeze occurs several degrees colder. Frost sometimes occurs at temperatures between 33 and 36 degrees, especially in more rural areas, resulting in minor damage to vegetation.

Most vegetation is destroyed when temperatures reach 28 degrees or colder, which is called a hard freeze, according to NOAA.

Chris Dolce has been a senior meteorologist with weather.com for over 10 years after beginning his career with The Weather Channel in the early 2000s.