Tornadoes can occur at any time of the year. In the southern states, peak tornado occurrence is in April through June, while peak months in the northern states are during the summer. Tornadoes are most likely to occur between 3:00 pm and 9:00 pm, but have been known to occur at all hours of the day or night.
Watches versus Warnings
Many people confuse the meaning of a tornado "watch" and tornado "warning" issued by the National Weather Service. Here's the difference:
Watch - Tornadoes are possible in your area; remain alert for approaching storms.
Warning - A tornado has been sighted or indicated by weather radar. If a tornado warning is issued for your area and the sky becomes threatening, move to your pre-designated place of safety.
Safety & Preparedness
It is important to remain alert to signs of an approaching tornado and seek shelter if threatening conditions exist. Look for environmental clues including a dark sky, large hail or a loud roar. If a warning is issued, move to a pre-designated shelter such as a basement; stay away from windows.
Categorical Convective Outlooks
The Storm Prediction Center is now using Categorical Convective Outlooks to help predict severe thunderstorms and tornado outbreaks. These outlooks are available online.