When and where are tornadoes most common in Texas?
NOAA data shows 9,535 tornadoes were reported statewide between Jan. 1, 1950 and Dec. 31, 2021.
AUSTIN (KXAN) — The Lone Star State is no stranger to tornadoes. March 2022's outbreak is a good reminder of that.
More than 9,500 tornadoes were reported in Texas between 1950 and 2021, 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 9,535 tornadoes were reported statewide between Jan. 1, 1950 and Dec. 31, 2021.
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 it crosses into a new county.
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 graph 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 123.8 in 2021. Some meteorologists see this as evidence that "Tornado Alley" is shifting away from Texas and more toward the southeastern U.S.
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 2,943 tornadoes reported between 1950 and 2021. That breaks down to an average of 40.9 tornadoes every May.
So, where are tornadoes most common? Every one of Texas' 254 counties saw at least one tornado between 1950 and 2021. According to the NOAA data, Harris County, home to Houston, has recorded the most twisters: 242 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.
When adjusted for the area, Galveston County sees the most tornadoes. The county saw a total of 32.69 tornadoes per 100 square miles between 1950 and 2021. Johnson County, south of Fort Worth, is second with 14.21 tornadoes per 100 square miles. Harris County is third with 14.18 per 100 square miles.
In the KXAN viewing area, Travis County saw the most tornadoes between 1950 and 2021, with 68. Williamson County was close behind with 67 reported tornadoes. Llano County had the fewest, with 11.
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 9,535 tornadoes reported between 1950 and 2021, 77% were rated either F0/EF0 or F1/EF1.
Violent tornadoes — those rated F4/EF4 and F5/EF5 — are much rarer. Only 87 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):
- May 11, 1953: McLennan County (Waco), causing 114 deaths, 597 injuries and $25 million in property damage. This is the deadliest tornado in Texas history.
- April 3, 1964: Wichita County (Wichita Falls), causing 7 deaths, 111 injuries and $25 million in property damage
- May 11, 1970: Lubbock County (Lubbock), causing 26 deaths, 500 injuries and $250 million in property damage
- May 6, 1973: McLennan County (Valley Mills), causing no deaths or injuries
- April 19, 1976: Brown County (Brownwood), causing no deaths, 11 injuries and $2.5 million in property damage
- May 27, 1997: Williamson County (Jarrell), causing 27 deaths, 12 injuries and $40 million in property damage
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
Since 1950, Texas has seen 15 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 at least 31 tornadoes in Texas, according to local NWS offices. That means the day ranks fourth for most tornadoes reported in a single calendar day. The NWS office in Fort Worth reported 17 tornadoes, Austin/San Antonio reported five, Houston reported five, and Shreveport reported four in its coverage area in Texas.