Grand Junction, CO Weather

Grand Junction has a semi-arid climate , almost grading into an arid type. Grand Junction sits in a large area of high desert lands in Western Colorado. Winters are cold and dry, with a January mean temperature of 27.4 °F (−2.6 °C). Due to its location west of the Rockies, Grand Junction does not receive as much influence from the Chinook winds as locations in Colorado east of the Front Range, yet it does receive protection from the Arctic air masses that can settle to the east of the Rockies. This is illustrated by the fact that from December to February, highs reach 50 °F (10 °C) only 18 days. Lows drop to 0 °F (−17.8 °C) or below on 2.9 nights per year. Snowfall is low compared to much of the rest of the state, averaging 19.1 inches (49 cm) per season; only once in the entire period of record dating to 1893, has observed 10 inches (25 cm) in a calendar day, though the median is 6.3 inches (16.0 cm), and moreover, snow cover is intermittent. Snow is greatest in December and January. Spring warming is gradual but quickens when nearing June; the average last freeze date is April 24. Summer is hot but dry, with a July mean temperature of 78.2 °F (25.7 °C). Grand Junction averages 64.5 days a year with temperatures at 90 °F (32 °C) or above, and an average 6.5 days attaining 100 °F (38 °C) or more. Autumn cooling is rapid, with the average first freeze date being October 15. The area receives little precipitation year-round, averaging 9.42 inches (239.3 mm), with no real seasonal spike. Sunshine hours are abundant, even in winter, and total just over 3200 hours per year, or 73% of the possible total.