May Brings The Most Killer Tornadoes To Oklahoma Each Year

It's no secret that tornadoes can happen at any time of year in tornado alley. But in Oklahoma's history, the most killer tornadoes have routinely appeared in May. These are tornadoes that have caused at least one fatality, according to Meteorologist Doug Spheger with the National Weather Service in Norman, Oklahoma.

Many Oklahomans still remember the tragic weather outbreak of May 3, 1999 that produced one of the deadliest tornadoes in Oklahoma history. Some of the same people have also lived through the destructive EF5 tornado that hit Moore, Oklahoma directly on May 20, 2013.

These are only two of the 43 killer tornadoes that have hit Oklahoma in May since 1950, making it the most deadly month in tornado season.

Anniversary of one of Oklahoma's deadliest tornadoes approaching on May 20.

"2013 was a weird year for tornadoes," according to YouTube researcher Alferia. "Most of the tornado season for that year was relatively quiet until mid-May. And most of the activity was contained within the last half of that month."

Alferia recounted what led up to the EF5 that struck Moore, Oklahoma on May 20, 2013. He explained that conditions were lined up just perfectly for severe weather to happen along the dryline between May 19 and May 22, 2013.

According to many people who experienced the May 3 tornado, they felt as though they were reliving the past all over again on May 20, 2013. This year, there are some eery similarities already happening in the weather.

Could this be the year where Oklahoma history repeats itself?

Many weather patterns this year seem to be similar to what was happening back in 2013. For instance, we currently have neutral El Niño-Southern Oscillation (ENSO) conditions, which was also the case 12 years ago when the Moore tornado developed.

That year, there was also talk of a strong cap in place for most of the day until it broke near sunset, according to 3Newsnow. This year, meteorologists have already noted a similarly strong cap in place, specifically for this weekend. However, the cap does seem to be weakening starting Sat., May 17, according to Meteorologist Mike Morgan.

Another major similarity was the recipe for severe weather being forecasted days ahead of time. In 2013, Oklahomans knew about the possibility for dangerous tornadoes at least a day in advance. This year, the National Weather Service has already started announcing the possibility for severe weather this weekend as of today, May 13, 2025.

Despite all of the similarities between this year and 2013, it is still Oklahoma. Things change constantly and, although weather analysts are always doing their best to report accurately, Mother Nature ultimately has a mind of its own.

Why do most of the killer tornadoes hit during May each year?

But there's a reason that May seems to be the prime-time month for tornado season,  according to Fox News. Comments have been edited for clarity.

This time of year typically has all of the ingredients for deadly storms, including "a combination of wind [shear], lift, surface heating and moisture.

In May, the jet stream (the stream of strong winds aloft) tends to still be overhead sending [potent] storm systems across our region."

The jet stream typically lifts to the north when summer arrives, so the mixture falls apart and we're left with the scorching heat in mid-June. But, as we've seen, tornadoes can happen at any time in Oklahoma.

Oklahomans should still stay weather-aware, especially in the most dangerous month of the year for tornado season.