Q: What exactly is a hard freeze?
A: There are several types of freezes, explains Brent McRoberts of Texas A&M University, and they are classified according to their severity. “In general terms, a hard freeze occurs when the air temperature is 26 degrees or lower for at least four hours. Because of the cold temperatures, it usually means that many types of plants and most seasonal vegetation will be destroyed.”
Q: What are the other types of freezes?
A: A light freeze occurs when the temperature gets between 29 to 32 degrees, and this kind of freeze can kill tender plants but not harm others, McRoberts adds. “A moderate freeze occurs at 25 to 28 degrees and this can destroy most types of vegetation, especially fruit plants. All freezes are tough on plants, but a hard freeze is the worst. It is often called a ‘killing freeze’ because it kills most of the plants affected. Hard freezes are common in northern states and higher altitudes, but usually only several will occur each winter in most parts of Texas.”
Weather Whys is a service of the Department of Atmospheric Sciences at Texas A&M University.