Tornado climatology
The United States averaged 1,274 tornadoes per year in the last decade. April 2011 saw the most tornadoes ever recorded for any month in the US National Weather Service's history, 875; the previous record was 542 in one month. It has more tornadoes yearly than any other country and reports more violent (F4 and F5) tornadoes than anywhere else.
Canada Tornado Alley
Ontario reports the most tornadoes of any province due to its large population, in addition to its proximity to Canadian Tornado Alley. Saskatchewan, Alberta and Manitoba rank in second place behind Ontario but rank before Quebec.