From 1950 to 1999 the month of April had the highest average number of tornado-related deaths. During the last half of the 20th century an average of 27 people died annually from tornadoes in April. However, tornadoes can occur at any time of the year. In the southern states, peak tornado occurrence is in March through May, while peak months in the northern states are during the summer. Tornadoes are most likely to occur between 3 and 9 p.m. but have been known to occur at all hours of the day or night.