The area has a humid continental climate (Koppel climate classification Dfb), but with winters that are milder than what the latitude and elevation may suggest: the January average is −9.6 °C (14.7 °F), and there are an average of 38 days from December to February where the high reaches or surpasses freezing. Winter months in which Pacific air masses dominate may thaw on a majority of days, as in January 2006 when the mean daily maximum temperature was 1.5 °C (35 °F). On the other hand, Arctic air masses can settle over the city for weeks at a time; in a rare case like January 1950, the temperature can stay well below freezing over a whole calendar month. Summer days are warm, with a July high of22.1 °C (72 °F), but lows are often cool, with monthly lows averaging below 10 °C (50 °F). The transitions between winter and summer, however, are short. There is some precipitation year-round, but February through April is the driest period. Snow averages 216 centimetres (85.0 in) each year, sometimes, but not always, falling in May and October, rarely later or earlier, respectively, than that
