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.

Average Temperature
Jan
37 °F
3 °C
Feb
39 °F
4 °C
Mar
52 °F
11 °C
Apr
65 °F
19 °C
May
64 °F
18 °C
Jun
81 °F
27 °C
Jul
88 °F
31 °C
Aug
90 °F
32 °C
Sep
79 °F
26 °C
Oct
59 °F
15 °C
Nov
53 °F
12 °C
Dec
41 °F
5 °C
Humidity
Jan
65%
Feb
55%
Mar
54%
Apr
39%
May
42%
Jun
30%
Jul
26%
Aug
19%
Sep
29%
Oct
22%
Nov
33%
Dec
61%
Rain
Jan
16mm
Feb
23mm
Mar
36mm
Apr
18mm
May
27mm
Jun
24mm
Jul
15mm
Aug
10mm
Sep
13mm
Oct
8mm
Nov
26mm
Dec
17mm
Clouds
Jan
31%
Feb
40%
Mar
40%
Apr
33%
May
40%
Jun
22%
Jul
12%
Aug
14%
Sep
12%
Oct
8%
Nov
11%
Dec
38%
Air quality US AQI
Jan
35
Feb
21
Mar
17
Apr
15
May
14
Jun
15
Jul
17
Aug
21
Sep
19
Oct
20
Nov
30
Dec
32
Sun
Jan
2UVI
Feb
3UVI
Mar
5UVI
Apr
7UVI
May
7UVI
Jun
9UVI
Jul
10UVI
Aug
9UVI
Sep
8UVI
Oct
5UVI
Nov
3UVI
Dec
2UVI