Spring and Fall Freeze Dates and Probabilities for Southeastern North Carolina and Northeastern South Carolina

Average Date of the Last Spring Freeze Location Date Wilmington, NC Mar 18 Castle Hayne, NC Apr 3 Willard, NC Apr 1 Southport, NC Mar 24 Elizabethtown, NC Mar 31 Whiteville, NC Mar 30 Longwood, NC Apr 1 Lumberton, NC Apr 1 Florence, SC Mar 21 Conway, SC Mar 15 Georgetown, SC Mar 12 Brookgreen Gardens, SC Mar 24 McColl, SC Mar 28 Dillon, SC Mar 30 Marion, SC Mar 30 Darlington, SC Mar 26 Lake City, SC Mar 24 Kingstree, SC Mar 27 Andrews, SC Mar 20 Pee Dee, SC Mar 27

The map and table above show the average date of the last Spring Freeze calculated for a number of locations using data from 1950-2010. The actual date of the last freeze can vary tremendously from year to year, sometimes occurring as early as February near the coast and as late as April or even early May inland. The date of the last Spring Freeze determines when cold-sensitive plants (including most annual garden vegetables) can safely be moved outside.
 

Average Date of the First Fall Freeze Location Date Wilmington, NC Nov 16 Castle Hayne, NC Nov 4 Willard, NC Nov 4 Southport, NC Nov 12 Elizabethtown, NC Nov 2 Whiteville, NC Nov 1 Longwood, NC Oct 31 Lumberton, NC Oct 31 Florence, SC Nov 10 Conway, SC Nov 15 Georgetown, SC Nov 22 Brookgreen Gardens, SC Nov 14 McColl, SC Nov 2 Dillon, SC Nov 1 Marion, SC Oct 30 Darlington, SC Nov 4 Lake City, SC Nov 8 Kingstree, SC Nov 2 Andrews, SC Nov 13 Pee Dee, SC Nov 5

The map and table above show the average date of the first Fall Freeze calculated for a number of locations using data from 1950-2010. The actual date of the first freeze can vary tremendously from year to year, sometimes occurring as early as October and as late as December at the coast. The date of the first Fall Freeze determines when cold-sensitive plants (including most annual garden vegetables) need to be moved indoors or harvested.

Average Length of the Growing Season Location Growing Season Length (Days) Wilmington, NC 242 Castle Hayne, NC 213 Willard, NC 215 Southport, NC 233 Elizabethtown, NC 213 Whiteville, NC 215 Longwood, NC 210 Lumberton, NC 212 Florence, SC 232 Conway, SC 244 Georgetown, SC 255 Brookgreen Gardens, SC 231 McColl, SC 218 Dillon, SC 214 Marion, SC 213 Darlington, SC 223 Lake City, SC 227 Kingstree, SC 218 Andrews, SC 238 Pee Dee, SC 222

The map and table above show the average length of the Growing Season calculated for a number of locations using data from 1950-2010. The actual length of the Growing Season can vary tremendously from year to year, sometimes totalling less than 200 days in a cold year to nearly 300 days along the coast in a particularly warm year. The Growing Season begins after the final Spring Freeze has occurred, and runs until the first freeze occurs in the Fall. The number of days in the Growing Season can help determine what plants can be grown in a particular climate. Growing Season length is also useful in comparing climates from different areas, or even from the same area over different times.

Frequently Asked Questions

What should I plant in my garden this year based on this information?

North Carolina State University and Clemson University have put together excellent State-specific resources for various garden vegetables including varieties and times needed to mature for harvest: NCSU Planting Guide, and Clemson Planning a Garden

Note that even in the coldest years in Eastern North or South Carolina there is plenty of time in the Growing Season to grow virtually any type of garden vegetable. Drought or extreme heat are normally much larger concerns for farmers and gardeners.

Why does the date of the last Spring Freeze (or first Fall freeze) vary so much from place to place?

Many factors determine how much nighttime temperatures vary from place to place. It's worth mentioning first of all that there are two types of freeze events: an advective freeze, and a radiational freeze. An advective freeze occurs when strong winds (usually northwest or north winds) bring cold air into the region. Since winds continue blowing through night any small-scale temperature variations are evened out quickly. Temperatures vary only a little from place to place during an advective freeze. On nights when skies are clear and winds are calm, a very different event occurs called a radiational freeze. On these nights microclimates appear where temperatures can vary widely from neighborhood to neighborhood, or even from your frontyard to your backyard. Differences in tree cover and vegetation, proximity to water, slope and elevation, and even soil type help create these temperature differences.

Soil type and proximity to water seem to have the most impact here in the Eastern Carolinas. Peat or mixed-peat/sand soils like are found in Carolina Bays and pocosin swamps produce the coldest nights and shortest growing seasons. Proximity to water (ocean, or large rivers and lakes) often provides locally warmer temperatures, extending the Growing Season length.

Are the first and last dates for freezing temperatures changing?

Thoughout the period 1950 through 2010 most stations in the Eastern Carolinas showed increases in the length of the Growing Season caused mainly by later first Fall Freezes. Overall changes in the length of the growing season have been small.  Climate changes over long period that are sometimes difficult to see from the perspective of a human lifespan; observed changes in Growing Season length over the previous 60 years are not guaranteed to continue at the same rate in the future.

What is the source of the data used on this website?

For Wilmington, NC and Florence, SC weather observations used in this study were collected at the local airports using climate observations overseen by the National Weather Service. The remainder of the stations used here are part of the NWS Cooperative Observation Program, a network of thousands of volunteer observers who report their highs, lows and daily precipitation to the National Weather Service. Official equipment and training is provided by the National Weather Service to ensure the data collected is high quality. The countless hours of public service volunteered by Cooperative Observers over the years have been invaluable in establishing a more complete picture of the climate of the United States.


Page Author: Tim Armstrong
Page Created: Feb 27, 2012
Last Modified: Aug 2, 2015