August 1, 2016 | Number of The Day
Average number of lightning strikes in NJ annually

Those summer storms that came blowing through New Jersey broke the back of the heat wave, and doubtless wreaked some havoc due to lightning. In a single year, lightning (known to the weather-wise as “cloud-to-ground flashes”) can strike the Garden State as many as 64,377 times (at least it did in 2011, the most recent year for which data is available). That’s actually a fairly low number: New Jersey was ranked 27th in the continental U.S. for “flash density” (the number of strikes per square mile); neighboring Pennsylvania came in 26th (6.9) and New York was 32nd (4.6).

To get a feel for what serious flash density is like, Florida, which was ranked No. 1, had 24.7 strikes per square mile and a grand total of 1,414,284 flashes.

The most damaging lightning strike in the Garden State occurred in 1926, when a bolt hit the Lake Denmark Naval Ammunition Storage Depot, part of the Picatinny Arsenal in Rockway Township. At the time, millions of metric tons of WWI surplus ammunition was being stored on site.

The strike kindled a fire, setting off more than 600,000 metric tons of explosives; destroying nearly 200 buildings; and killing 21 people.

The disaster caused $47 million in damages and is considered one of the largest manmade explosions in U.S. history.

Lightning doesn’t need surplus ammunition to be deadly. The National Weather Service has posted a safety tips video to YouTube for what to do if you’re caught in a storm — driving, boating, or hiking.