Yukon has a sub-arctic continental climate with temperatures reaching as high as 36.1 degrees celcius in the summer and as low as minus 60 degrees celcius in the winter. The average frost free period ranges from 93 days in the Watson Lake area to 21 days at Haines Junction. As well as varying greatly geographically, frost free periods variy substantially from year to year at any location. Long hours of daylight during the summer promote rapid growth which compensates to some extent for the cooler summer temperatures experienced north of 60 degrees latitude.
Average annual precipitation ranges from less than 20 cm west of Whitehorse to more than 40 cm in Watson Lake. The Southwest Yukon, where most agricultural production occurs, lies within the rainshadow created by the St. Elias and Coastal mountains. South-west Yukon is subject to droughts between April and July -- a particular problem for crop germination.