Downtown Billings has a hot-summer humid continental climate depending on the isotherm used, closely bordering on semi-arid , with dry, hot summers, and cold, dry winters. However, areas outside of downtown can have a hot-summer continental climate, even with the -3C/27F isotherm, due to the urban heat island effect, as exemplified by the Billings Logan International Airport. In the summer, the temperature can rise to over 100 °F or 37.8 °C (1 to 3 times per year) while the winter will bring temperatures below 0 °F or −17.8 °C on an average of 17 to 18 nights per year. The snowfall averages 55 inches or 1.40 metres a year, but because of warm chinook winds that pass through the region during the winter, snow does not usually accumulate heavily or remain on the ground for long: the greatest depth has been 33 inches or 0.84 metres on April 5, 1955, after a huge storm which dumped 4.22 inches or 107.2 millimetres of water equivalent precipitation as snow in the previous three days under temperatures averaging 26.7 °F (−2.9 °C).
The snowiest year on record was 2014 with 103.5 inches or 2.63 metres, topping the 1996–97 previous record of 98.9 inches or 2.51 metres. The first freeze of the season on average arrives by October 4 and the last is May 7. Spring and autumn in Billings are usually mild, but brief. Winds, while strong at times, are considered light compared with the rest of Montana and the Rocky Mountain Front.
Due to its location, Billings is susceptible to severe summer weather as well. On June 20, 2010, a tornado touched down in the Billings Heights and Downtown sections of the city. The tornado was accompanied by hail up to golf ball size, dangerous cloud-to-ground lightning, and heavy winds. The tornado destroyed a number of businesses and severely damaged the 12,000-seat MetraPark Arena.