Greene County and much of upper East Tennessee are under a frost advisory for Tuesday morning. The National Weather Service expects lows tonight around 34 degrees. The highest likelihood of frost developing will be between 4:00 AM and 9:00 AM.
The “last spring frost” date for Greene County is April 28, based on data from NOAA and the National Weather Service. That means that there is less than a 30% frost after that date, although it isn’t impossible.
The classification of freeze temperatures is based on their effect on plants:
- Light freeze: 29° to 32°F (-1.7° to 0°C)—tender plants are killed.
- Moderate freeze: 25° to 28°F (-3.9° to -2.2°C)—widely destructive to most vegetation.
- Severe freeze: 24°F (-4.4°C) and colder—heavy damage to most garden plants.
Note that frost dates are only an estimate based on historical climate data and are not set in stone. The probability of a frost occurring after the spring frost date or before the fall frost date is 30%, which means there is still a chance of frost occurring before or after the given dates.
Frost can occur even when the air temperature is just above freezing. Official weather measurements are taken from an thermometer four to five feet above ground, and since colder air sinks, air at ground level can be several degrees lower than the recorded air temperature.
