<P> Officially , the widest tornado on record is the El Reno , Oklahoma tornado of May 31 , 2013 with a width of 2.6 miles ( 4.2 km ) at its peak . This is the width found by the National Weather Service based on preliminary data from University of Oklahoma RaxPol mobile radar that also sampled winds of 296 mph ( 476 km / h ) which was used to upgrade the tornado to EF5 . However , it was revealed that these winds did not impact any structures , and as a result the tornado was downgraded to EF3 based on damage . However , another possible contender for the widest tornado as measured by radar was the F4 Mulhall tornado in north - central Oklahoma which occurred during the 1999 Oklahoma tornado outbreak . The diameter of the maximum winds ( over 110 mph ( 49 m / s ) ) was over 5,200 feet ( 1,600 m ) as measured by a DOW radar . Although the tornado passed largely over rural terrain , the width of the wind swath capable of producing damage was as wide as 4 mi ( 6.4 km ) . </P>
<P> Officially , the widest tornado on record is the El Reno , Oklahoma tornado of May 31 , 2013 with a width of 2.6 miles ( 4.2 km ) at its peak . This is the width found by the National Weather Service based on preliminary data from University of Oklahoma RaxPol mobile radar that also sampled winds of 296 mph ( 476 km / h ) which was used to upgrade the tornado to EF5 . However , it was revealed that these winds did not impact any structures , and as a result the tornado was downgraded to EF3 based on damage . However , another possible contender for the widest tornado as measured by radar was the F4 Mulhall tornado in north - central Oklahoma which occurred during the 1999 Oklahoma tornado outbreak . The diameter of the maximum winds ( over 110 mph ( 49 m / s ) ) was over 5,200 feet ( 1,600 m ) as measured by a DOW radar . Although the tornado passed largely over rural terrain , the width of the wind swath capable of producing damage was as wide as 4 mi ( 6.4 km ) . </P>
where did the widest tornado on record occur
where did the widest tornado on record occur
El Reno , Oklahoma
El Reno , Oklahoma