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Wyoming · County tornado history

Johnson County, Wyoming tornadoes

NOAA’s Storm Prediction Center has recorded 22 tornadoes in Johnson County, Wyoming from 1950 through 2024, about one every 3.4 years. That ranks it 14 of 23 counties in Wyoming with a recorded tornado. The most recent was an EF1 on June 19, 2019.

Tornadoes since 1950
22
Since 2000
5
Strongest
EF2, June 1, 2018
Most recent
EF1, June 19, 2019
Peak month
June (14)
Per 1,000 sq mi
5
FEMA tornado risk
Very Low

F0/EF0 1 2 3 4 5 · Lines run from where each tornado touched down to where it lifted; dots are short paths. Neighboring counties are outlined.

When tornadoes hit Johnson County

June has brought the most, 14 of 22. About 86% touched down between 1 pm and 7 pm (Central Standard Time, as the Storm Prediction Center records it).

By decade

More tornadoes in recent decades mostly reflects better detection and reporting (Doppler radar, storm spotters, damage surveys), especially for weak EF0 tornadoes, not necessarily more storms. The 2020s bar covers only 2020 to 2024.

How strong they were

Rating Estimated 3-second gust Tornadoes
F0 / EF0 Light damage: 65 to 85 mph (EF scale) 13
F1 / EF1 Moderate: 86 to 110 mph 7
F2 / EF2 Considerable: 111 to 135 mph 2
F3 / EF3 Severe: 136 to 165 mph 0
F4 / EF4 Devastating: 166 to 200 mph 0
F5 / EF5 Incredible: over 200 mph 0

Tornadoes before February 2007 were rated on the original Fujita (F) scale; since then the National Weather Service uses the Enhanced Fujita (EF) scale. Wind speeds above are EF-scale estimates from damage, not measurements. See what the EF scale means.

The strongest tornadoes in Johnson County

Date Rating Path length Path width Deaths Injuries
June 12, 2017 EF2 1.6 mi 250 yd
June 1, 2018 EF2 1 mi 300 yd
August 14, 1974 F1 1.5 mi 67 yd 2
June 3, 1971 F1 1 mi 27 yd
July 23, 1973 F1 0.1 mi 10 yd
May 9, 1977 F1 4.5 mi 27 yd
June 20, 1977 F1 0.1 mi 10 yd
August 11, 1999 F1 0.2 mi 0 yd
June 19, 2019 EF1 4.1 mi 250 yd
June 18, 1979 F0 0.3 mi 100 yd

Deaths and injuries are for each tornado’s whole path, which can cross other counties.

Most recent tornadoes

Date Rating Path length Path width Deaths Injuries
June 19, 2019 EF1 4.1 mi 250 yd
June 1, 2018 EF2 1 mi 300 yd
June 12, 2017 EF2 1.6 mi 250 yd
June 1, 2010 EF0 0.1 mi 25 yd
May 29, 2008 EF0 0.1 mi 10 yd
August 11, 1999 F1 0.2 mi 0 yd
June 11, 1998 F0 0.1 mi 30 yd
June 22, 1995 F0 0.2 mi 10 yd

The official database ends with 2024. For storms since then, see the Storm Prediction Center’s reports and your local National Weather Service office.

FEMA’s tornado risk rating

FEMA’s National Risk Index rates the tornado risk in Johnson County as very low, with a score of 16 out of 100 compared with every other U.S. county. It estimates about 0.49 tornadoes a year here and an expected annual loss of about $145,146 to buildings, people and farming. The index mixes how often tornadoes strike with what is exposed and how well a community can recover, so a busy rural county can rate lower than a less active city.

Neighboring counties

Staying safe

When a tornado warning is issued, act at once. Go to a basement, storm shelter or safe room. With none, use a small windowless room on the lowest floor, as far from outside walls as you can, and cover your head and neck. Mobile homes and cars are not safe places to ride out a tornado: leave early for a sturdy building or shelter. Read the full tornado safety guide and the National Weather Service advice linked below.

Sources

Sources last checked 1 November 2026.

Frequently asked questions

How many tornadoes has Johnson County had?

22 from 1950 through 2024 in NOAA’s Storm Prediction Center database, 5 of them since 2000.

When was the last tornado in Johnson County?

The most recent in the official record was an EF1 on June 19, 2019. Later storms are not yet in the final database.

What was the strongest tornado in Johnson County?

An EF2 on June 1, 2018, with a 1-mile path.

When is tornado season in Johnson County?

June has had the most tornadoes here. Across the U.S. the peak runs from spring into early summer, and the South also sees tornadoes in late fall and winter.