Grand Valley's Growing Season
Grand Junction's mountain valley location, with attendant "valley breezes", provides protection from spring and fall frosts, resulting in a growing season averaging 191 days.

Summertimes
"Pleasantly warm and dry" would be an apt description of the Grand Junction summer. Although the record temperature of 105° was reached years ago, summer temperatures rarely top 100° with the highs normally in the upper 80's and low 90's. Summer low temperatures are commonly in the 60's.

Precipitation annually averages between a half an inch a month to just over an inch in the summer. The occasional summer breezes of 7 to 8 m.p.h. serve to freshen the days and nights. The rains that do occur are chiefly scattered light showers due to the thundershowers which develop over the nearby mountains. Relative humidity is very low during the summer, with values close to those of other dry localities such as the southern parts of New Mexico and Arizona.

Wintertimes
Winters in Grand Junction can only be classified as mild, and especially so for a city in Colorado. Winter snows are fairly frequent, but mostly light and quickly melt away. Even the infrequent snows of 4 to 8 inches, which are heavy for this area, rarely remain on the gorund for prolonged periods of time. Blizzard conditions in Grand Junction are extremely rare.

Although the temperature dipped to a record low of -23° one January, winter temperatures normally range from the low 20's to the mid 40's. Again, due to the protected locality, sudden and severe weather changes are few and far between. The sunny days are many because sunny days predominate all seasons in Grand Junction. The average number of sunny to mostly sunny days is 248 or 68%.

Typical Spring and Fall
Grand Junction's mild summers and equally mild winters are separated by long blossoming springs and falls splashed with blazing colors.

Flying Conditions
Flying weather conditions are exceptionally favorable for operation of light airplanes, with visibilities of 20 miles or more. Ceilings are at 5,000 feet or higher approximately 95% of the time. Gusty surface winds are rather frequent in the spring and early summer, but even lighter-than­air craft find favorable flying conditions most other times in the Grand Junction skies.

Weather Extremes
As previously noted, Grand Junction is not an area of weather extremes. The last flood of major significance was in 1957, and there are no recorded tornados. Heavy fog (visibility of 1/4 mile or less) is rare, averaging 8 days a year. Snowfall depths average from just 3 to 4 inches in any given winter month.

Grand Junction Climate
Statistics By Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Precipitation	.59	.58	.76	.74	.73	.44	.61	1.03	.89	.90	.59	.58
Snowfall	7.5	4.2	4.3	1.2	-	-	-	-	.01	.06	3.0	5.4
Relative Humidity at 5 am	81	57	49	45	38	29	44	46	47	49	71	75
Relative Humidity at 5 pm	59	25	24	22	20	12	23	20	22	25	49	52
Maximum Temperature	37	44	53	65	79	86	93	89	81	68	51	39
Minimum Temperature	17	23	30	39	49	57	64	62	53	42	29	20
Windspeed	5.6	6.7	8.4	9.7	9.6	9.8	9.3	9.0	9.0	7.9	6.6	5.9
Percentage Sunshine	60	65	65	67	71	78	77	75	79	74	64	60

U.S. City Comparisons
Annual Averages	Sunshine (%)	Rain (Inches)	Snowfall (Inches)	Wind Speed (mph)	Days over 90°	Days below 32°	Days of Heavy Fog
Grand Junction	68%	8.41	26.3	8.1	66	24	8
Minneapolis	58%	25.94	40.2	10.6	14	158	11
Chicago	57%	34.44	33.2	10.3	21	118	13
Seattle	45%	35.65	11.4	9.3	2	14	47
Denver	70%	15.51	55.4	9.0	32	164	10
Washington D.C.	57%	38.89	19.5	9.2	37	74	13
New York City	59%	40.19	27.1	9.4	16	81	14
Atlanta	61%	48.34	1.6	9.1	19	58	30
Omaha	62%	30.18	28.4	10.9	36	138	15
San Fransisco	67%	20.66	.02	8.7	1	0	17

Information courtesy of the Weather Service Office of the National Oceanic & Atmospheric Administration, Walker Field, Grand Junction Colorado. This page based on a brochure published by Grand Junction Area Chamber of Commerce (970) 242-3214.

Email us at weather@westerncolorado.com

All contents of this page - Copyright Western Colorado Internet Moarketing Co. 1996.