From January to March 2017, various weather forecast offices of the National Weather Service confirmed at least 366 tornadoes across the United States, activity well beyond climatological norms. Based on the 1991–2010 average, the first month of the year is expected to see 35 tornadoes, with 29 occurring in February and 80 forming throughout March. In 2017, however, the count for the first three months was 193, 72, and 101, respectively. Activity began with the development of an EF0 tornado west of Brooksville, Mississippi at 23:08 UTC on January 5. The latest storm of the period was an EF1 that touched down southeast of Powellsville, North Carolina at 22:15 UTC on March 31. Five tornadoes managed to attain an EF4 rating, one in Tupelo, Mississippi on January 5; three in a large outbreak on February 25; and another in Danville, Illinois on April 17. Meanwhile, the deadliest tornado of the period was the EF4 Tupelo tornado, killing 19 people.
The first month of the year featured the second-highest tornado count on record, surpassed only by 1999. A total of 193 tornadoes were confirmed, largely resultant from a major outbreak that affected the United States from January 16–18. This particular event was the largest January outbreak on record (with 135 confirmed tornadoes), beating out the previous record holder of January 21–23, 1999, and the largest wintertime outbreak overall, exceeding the counts set by the aforementioned incident and the 2008 Super Tuesday tornado outbreak. February, meanwhile, featured 72 tornadoes, a count well below that of the preceding month's but still over twice the long-term average. An outbreak on February 25 produced 53 tornadoes and 22 fatalities. Activity largely subsided for the first half of March. However, with a localized outbreak of 12 tornadoes on March 15 and another event consisting of 64 tornadoes a week later, as well as continued activity in the following week, March observed preliminary count of 101 tornadoes.