Last updated: March 2, 2024
Under the Köppen–Geiger climate classification Grand Junction features a humid continental climate (Dfa). Temperatures typically range between -6 °C (22 °F) and 25 °C (77 °F) through the year, but rarely can drop to -30 °C (-22 °F) or can rise to as high as 39 °C (102 °F). The average annual precipitation amounts to about 954 mm (37.6 inches) and receives 103 rainy days on the 1 mm (0.04 inches) threshold annually. Grand Junction enjoys an average of 3003 hours of sunshine throughout the year, and daylight varies from 9 hours 9 minutes to 15 hours 10 minutes per day.
The warmest months in Grand Junction are June, July and August, with daily mean temperatures ranging from 23 to 25 °C (74 - 77 °F) throughout the day. The coldest temperatures usually occur in January, February and December, when daily mean temperatures range from -6 to -1 °C (22 - 30 °F) throughout the day. On average each year, Grand Junction experiences 97 days above 25 °C (77.0 °F) and 125 days below 0 °C (32.0 °F).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum | 13°C (56°F) |
21°C (70°F) |
25°C (77°F) |
31°C (88°F) |
36°C (98°F) |
39°C (102°F) |
36°C (97°F) |
37°C (99°F) |
36°C (96°F) |
32°C (90°F) |
26°C (79°F) |
22°C (72°F) |
| Mean maximum | 11°C (52°F) |
15°C (59°F) |
21°C (71°F) |
27°C (80°F) |
33°C (91°F) |
34°C (93°F) |
34°C (94°F) |
33°C (92°F) |
33°C (92°F) |
30°C (86°F) |
19°C (67°F) |
16°C (62°F) |
| Average high | -1°C (30°F) |
-0°C (32°F) |
9°C (49°F) |
15°C (60°F) |
22°C (72°F) |
29°C (84°F) |
30°C (86°F) |
28°C (83°F) |
26°C (78°F) |
16°C (61°F) |
9°C (48°F) |
4°C (39°F) |
| Daily mean | -6°C (22°F) |
-5°C (23°F) |
4°C (39°F) |
9°C (49°F) |
17°C (62°F) |
23°C (74°F) |
25°C (77°F) |
23°C (74°F) |
20°C (68°F) |
11°C (52°F) |
3°C (38°F) |
-1°C (30°F) |
| Average low | -10°C (14°F) |
-10°C (14°F) |
-1°C (31°F) |
4°C (39°F) |
12°C (53°F) |
18°C (65°F) |
20°C (67°F) |
18°C (64°F) |
14°C (58°F) |
6°C (43°F) |
-2°C (29°F) |
-6°C (22°F) |
| Mean minimum | -24°C (-11°F) |
-23°C (-10°F) |
-11°C (12°F) |
-7°C (20°F) |
3°C (39°F) |
11°C (53°F) |
14°C (57°F) |
12°C (54°F) |
7°C (44°F) |
-3°C (27°F) |
-12°C (11°F) |
-16°C (4°F) |
| Minimum | -30°C (-21°F) |
-30°C (-22°F) |
-21°C (-5°F) |
-11°C (12°F) |
1°C (34°F) |
9°C (48°F) |
12°C (55°F) |
10°C (51°F) |
4°C (39°F) |
-7°C (20°F) |
-19°C (-2°F) |
-23°C (-9°F) |
Compare temperature, precipitation, sunshine, UV index in Grand Junction, Iowa, United States with other places around the world.
Grand Junction usually has the most precipitation in May, September and October, with an average of 11 rainy days and 131 mm (5.2 inches) of precipitation per month. The driest months in Grand Junction are January, November and December. On average, 35 mm (1.4 inches) of precipitation falls during these months.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average precipitation mm (inches) | 32 (1.3) | 39 (1.5) | 76 (3.0) | 66 (2.6) | 163 (6.4) | 101 (4.0) | 84 (3.3) | 90 (3.5) | 108 (4.2) | 122 (4.8) | 36 (1.4) | 37 (1.4) |
| Average precipitation days (≥ 1 mm) | 6 | 8 | 8 | 9 | 15 | 10 | 7 | 9 | 10 | 10 | 6 | 5 |
The sunniest months in Grand Junction are June, July and August, when the sun shines an average of 11 hours 16 minutes a day. Least sunny months in Grand Junction: January, February and November receive an average of 6 hours 0 minutes of sunshine daily.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean monthly sunshine hours | 138 | 194 | 217 | 252 | 252 | 341 | 370 | 324 | 271 | 219 | 208 | 211 |
| Mean daily daylight hours | 9h 30m | 10h 35m | 11h 58m | 13h 23m | 14h 34m | 15h 10m | 14h 50m | 13h 46m | 12h 25m | 11h 0m | 9h 47m | 9h 9m |
Grand Junction experiences the highest level of ultraviolet (UV) radiation in June, July and August, when the maximum UV index can reach values of 9 - 11, which corresponds to the Very High / Extreme category of sun exposure. January, November and December are in the Moderate exposure category. In these months, the maximum values of the UV index do not exceed 4. For more detailed information, check out our hourly Grand Junction UV Index data.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV Index (month maximum) | 3 | 5 | 5 | 8 | 9 | 11 | 10 | 9 | 8 | 6 | 4 | 3 |
Discover in-depth weather details for every month in Grand Junction. Click through the links below for comprehensive overviews of temperature trends, precipitation levels, sunshine hours, and solar UV radiation specifics. Whether planning a visit or simply curious about Grand Junction's climate nuances, these monthly breakdowns provide the information you need for an informed understanding of what to expect throughout the year.
Each link leads to a detailed account of the typical weather conditions for that month, providing both locals and tourists with vital information to plan their daily activities, wardrobe, and travel itineraries accordingly.