The National Weather Service has issued Frost Advisories and Freeze Warnings for a large portion of the northeast and Mid Atlantic. Frost Advisories are up from portions of Kentucky and Tennessee east to portions of North Carolina, Virginia, Maryland, and Delaware. Freeze Warnings are in effect for portions of Pennsylvania, New Jersey, New York, Virginia, and West Virginia. The area north of these frost and freeze advisories are also likely to see frost and freeze conditions, but because it is before the growing season starts there, the National Weather Service hasn’t issued any advisories there.

Typically, frost can occur when the temperature falls below 36°F, especially in rural areas. It is a localized phenomena and can be quite variable across a small area. While the National Weather Service does not keep track of “frost” in observations per se, they do keep track of when temperatures hit the freezing mark or fall below. Frost becomes more widespread when the temperature falls below 32°F with some freeze possible. A hard freeze is possible when temperatures fall below 28°F.

In a Freeze Warning, frost and freeze conditions will kill crops and other sensitive vegetation.

In a Frost Advisory, frost could kill sensitive outdoor vegetation if left uncovered.

When a Watch is issued, it is possible warning criteria could be met and a warning could eventually be issued.

The National Weather Service wants people in the impacted areas to take steps now to protect tender plants from the cold. “To prevent freezing and possible bursting of outdoor water pipes they should be wrapped, drained, or allowed to drip slowly. Those that have in-ground sprinkler systems should drain them and cover above-ground pipes to protect them from freezing,” the National Weather Service said in a statement.