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.
Tornadoes of 2015
Throughout much of the first half of 2015, tornado activity was near record low mostly due to a continuous pattern of a trough in the east, which brought colder than average temperatures there, and a ridge in the west, which brought warmer than average temperatures in the west. The pattern changed, slightly, in late March and early April to allow for some severe weather. During May, a few large tornado outbreaks occurred, which led it to be the most active tornado month since April 2011, and the most active May since 2008. Due to a significant El Niño event, November and December were extremely active months with over 20 fatalities in December alone. 93 tornadoes were reported in December, well above average for that month. Furthermore, 2015 was the first year since 2011 to see a total of more than 1,000 tornadoes across the United States. In synopsis, 2015 was the first average or above average year in terms of the number of tornadoes since 2011.Final totals through December 31
There were 32 tornadoes reported in the U.S. in January, of which 27 were confirmed.