The warning will be in effect early Thursday morning from 1:00 a.m. through 10:00 a.m.

PITTSBURGH (KDKA) — A freeze watch had been issued for the Pittsburgh area, but that has now been upgraded to a freeze warning.

The National Service issued the warning to go into effect early Thursday morning from 1:00 a.m. through 10:00 a.m.

In areas where the growing season has begun, any tender outdoor plants should be protected.