Tornadoes are most likely to occur late in the summer with minor peaks in March and December.  Other forms of severe weather are more likely to occur during the spring months, with April the most likely month for hail and May the most likely month for high winds.  November, however, shows a secondary maximum both for hail and high winds.
 

As the figure below shows, most severe weather occurs in the afternoons, with peak hours ranging from 3 PM for tornadoes to 4 PM for high wind events to 6 PM for hail storms.  Minor peaks occur during the early to late morning hours, varying from 1-2 AM for hail to 4 AM for high winds to 11 AM for tornadoes.
 

Total number of severe weather events per hour, by type.
The source of data is the Storm Prediction Center of the National Weather Service

As the figure below demonstrates, reports of severe weather in Louisiana have been increasing since the 1950's.  Especially dramatic are the increases in reports of hail and high winds beginning in the 1980's.  While climate changes may be responsible for some of this increase, the rather sudden changes that occurred from 1981 to 1995 suggest that two other factors are probably more important.  First, population in the state is increasing and people have become increasingly aware of the weather, so there is a greater likelihood that someone will observe a severe weather event and report it.  Second, the observational capabilities of the National Weather Service have improved because of the increased sensitivity in spatial and temporal resolutions and in magnitude of the Doppler weather radars and the increased number of surface observations.