U.S. Tornadoes: The Month of October by the Numbers

October is the fourth least productive month of the year when it comes to overall tornado counts. While there is a bit of a statistical peak during the month and into November, the idea of a “second season” is perhaps a misnomer as activity generally remains low, punctuated by some notable outbreaks.

Of course, the season never really ends, it just waxes and wanes. The cool air making stronger inroads across the country begins to shut tornado activity off across places which don’t often see them, or do only during the warmer months.

October Tornado Climatology (1950-2011)

Total tornadoes: 2,142 (-862 from September)
Climatological average (1991-2010): 61.2 (-12.7 from September)
10-year average (2002-2011): 65.4
10-year median (2002-2011): 70.5
Long-term average (1950-2011): 34.5
Monthly high: 117 (2001)
Monthly low: 0 (1952) / 1 (1987), lowest recent
Total fatalities: 99
Total injuries: 2,382

The tornadoes by day counts now show considerably more variability than previous months, owing to the fact that tornado days make up only about 1/3 of October days in the current climatological period (1991-2010). October is most on par with March on these counts, though decidedly less volatile, with outbreaks tending to be considerably smaller.

As with many months, the large state of Texas (averaging 10 per October) outranks all others by a considerable margin in overall tornado counts. Behind Florida (average of seven in October) in the number two spot, Louisiana, Oklahoma and Kansas round out the top five with more than 100 tornadoes each in the month. Places most favored for October tornadoes appear to be the southern Plains, parts of the South, the midwest and into the mid-Atlantic.

Significant tornadoes rated F2/EF-2 or higher made up 22.9% of all October tornadoes from 1950-2011, and they accounted for 92.9% of the deaths. The ratio of significant tornadoes is up from recent months, partly attributable to the fact that tornado hotspots in October cover more populated areas as the storm track shifts back south.

The deadliest tornado in October is an F4 spawned by Hurricane Hilda on October 3, 1964 in Louisiana. The tornado, which passed through Larose, is also the deadliest tornado produced by a tropical system since modern records began.

U.S. Tornado Climatology by Month

All: Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec
Significant: Jan | Feb | Mar | Apr| May | Jun | Jul | Aug | Sep | Oct | Nov | Dec

SPC tornado data obtained at the Tornado History Project. Images can be selected for larger versions. Get updates about U.S. Tornadoes on Twitter and Facebook. Official 2012 data will be available during spring 2013.