AUSTIN (KXAN) — More than 9,700 tornadoes have been reported across the Lone Star State since 1950, according to data from the National Oceanic and Atmospheric Administration (NOAA).

KXAN dug through the data to find out when and where tornadoes are most common in Texas.

NOAA data shows 9,750 tornadoes were reported statewide between January 1950 and August 2023.

The NOAA data splits tornadoes into multiple “segments.” If a tornado crosses a county or state line, it begins a new segment. Therefore, long-track tornadoes that are on the ground for an extended period of time may technically be counted more than once, if they cross into a new county.

How many tornadoes does Texas get in a typical year?

The most tornadoes reported in a single year was 258 in 2015, including the largest outbreak in Central Texas history. A total of 16 tornadoes touched down in the area over Memorial Day weekend, the strongest being an EF-2 twister in Milam County.

Only 13 tornadoes were reported statewide in 1952, the fewest for any year.

The chart above shows the number of tornadoes reported each year, along with the 10-year average. The average hit a peak of 172.7 tornadoes per year in 1999. Since then, the average per year has declined, to 125.9 in 2022. Some meteorologists see this as evidence that “Tornado Alley” is shifting away from Texas and more toward the southeastern U.S.

When are tornadoes most common in Texas?

Unsurprisingly, tornadoes in Texas are most common during the spring severe weather season. May, in particular, stands out above the other months, with a total of 2,989 tornadoes reported between 1950 and 2023. That breaks down to an average of 41.5 tornadoes every May.

Where in Texas are tornadoes most common?

Every one of Texas’ 254 counties saw at least one tornado between 1950 and 2023. According to the NOAA data, Harris County, home to Houston, has recorded the most twisters: 247 in total. That’s well above second-ranked Hale County, north of Lubbock, which had 132 tornadoes in that same time period.

Real County, west of San Antonio, and Menard County, southeast of San Angelo, both had two tornadoes, the fewest of any county in Texas.

The map below shows the approximate tracks of tornadoes in Texas between 1950 and 2022.

In the KXAN viewing area, Williamson County saw the most tornadoes between 1950 and 2023, with 71. Travis County is right behind with 70 reported tornadoes. Llano County had the fewest, with 11.

Where were the strongest tornadoes in Texas?

The National Weather Service uses the Enhanced Fujita Scale to determine how strong tornadoes are. The NWS does this by looking at damage caused and estimating the wind speeds the tornado likely produced. In Feb. 2007, the NWS revised the original Fujita Scale “to reflect better examinations of tornado damage surveys so as to align wind speeds more closely with associated storm damage.”

The majority of tornadoes in Texas are weak, according to the Enhanced Fujita Scale. Of the 9,750 tornadoes reported between 1950 and June 2023, 77% were rated either F0/EF0 or F1/EF1.

Violent tornadoes — those rated F4/EF4 and F5/EF5 — are much rarer. Only 89 such tornadoes were reported during the same time period, accounting for 0.9% of all tornadoes.

In fact, only six tornadoes have been rated F5 in Texas since 1950 (none have been rated EF5 since the switch to the Enhanced Fujita Scale):

Just 59 F5/EF5 tornadoes have been reported nationwide since 1950, meaning Texas accounts for about 10% of the nation’s strongest twisters.

The map above shows the strongest tornadoes reported in each county in Texas. Of the 254 counties statewide:

  • F5/EF5: 5 counties: Brown, Lubbock, McLennan, Wichita and Williamson
  • F4/EF4: 53 counties, including Bexar, Dallas, Harris and Travis
  • F3/EF3: 114 counties
  • F2/EF2: 65 counties
  • F1/EF1: 14 counties
  • F0/EF0: 3 counties: Edwards, Menard and Presidio

When were the biggest tornado outbreaks in Texas?

Since 1950, Texas has seen 16 calendar days that produced at least 25 tornadoes. The most reported in a single day was 67 on Sept. 20, 1967, associated with the landfall of Hurricane Beulah.

The outbreak on March 21, 2022, produced 45 tornadoes in Texas. That means the day ranks second for most tornadoes reported in a single calendar day.

May 12, 1982 is the only other day with at least 40 tornadoes reported in Texas.