Hailey has a continental Mediterranean climate (Köppen "Dsb"). Winters are cold and snowy: there are an average of forty-four days each year which fail to top , whilst 199 nights fall below freezing and nineteen nights between November and March will fall to or below . Spring warms up slowly, with snow falling as late as May. Summer is hot during the day, but cools off into the 40s or 50s at night. Highs reach on only 15 days per year, and only July has made it to . Freezing nights can happen any time of the year, even in July and August. There is little rain, coming only as isolated showers or storms a few times per month. Most days are sunny and this is the driest part of the year. Fall starts warm in September and then quickly cools off. Snow has fallen in September, but usually holds off until October. Early fall is dry and sunny like summer. Days in the 70s can happen well into October, but has been recorded in November. The lowest temperature recorded was on January 12, 1963 and the record high is on July 19, 1953. Precipitation falls primarily as snow in winter and as thunderstorms in late spring. The rest of the year is mostly dry.