Of the estimated 100,000 thunderstorms that occur each year in the United States, about 10% are classified as severe. The National Weather Service considers a thunderstorm severe if it produces hail that is one inch or larger or winds of 58 mph or stronger. Severe thunderstorms are known to cause significant damage to well-built structures or cause bodily harm. These strong storms can also produce frequent and dangerous lightning, flooding and tornadoes.


Thunderstorms can occur anywhere in Monmouth County. Typically New Jersey experiences about 20 days per year of thunderstorm activity and predominantly in the warmer months, March through October.

In the United States, there are an estimated 100,000 thunderstorms each year, of which approximately 10 percent reach severe status. Thunderstorms can produce tornadoes, strong winds, flash flooding and hail. Typical thunderstorms are 15 miles in diameter and last on average of 30 minutes. These typically short lived and smaller storms can be very dangerous and always produce lightning.

Severe Thunderstorm Watch – Issued by the Storm Prediction Center to alert the public that conditions are favorable for the development of severe thunderstorms in and close to the watch area. These watches are issued with information concerning the watch area and the length of time they are in effect. During the watch, people should review severe thunderstorm safety rules and be prepared to move a place of safety if threatening weather approaches.

Severe Thunderstorm Warning – Issued by local National Weather Service offices to warn the public that a severe thunderstorm has been sighted by storm spotters or has been indicated by radar. People in the affected area should seek safe shelter immediately.


  • Have a NOAA All-Hazards Weather Radio and battery backup to receive important weather and other emergency-related warnings.
  • Discuss thunderstorm safety with all members of your household or business. Locate or build a Safe Room in the interior of your home or business. This could be a basement or an interior room on the lowest portion of a structure that has no windows.
  • Check the weather forecast before leaving for extended periods outdoors and watch for signs of approaching storms while outside. Postpone outdoor activities if storms are imminent.
  • Sign up for local emergency warning systems.
  • Create and practice a communications plan that includes an emergency meeting place.