UV Index in Fort Collins, United States

Last updated: July 2, 2025

Understanding the UV Index is crucial for residents of Fort Collins, Colorado, as it helps in safeguarding your skin against harmful sun exposure. With UV levels peaking at an intense 12 around midday, being aware of the UV Index can play a vital role in preventing sunburn and promoting skin health. Fort Collins, nestled in a semi-arid climate, experiences elevated UV exposure due to its high altitude and sunny days, making it essential for outdoor enthusiasts and everyday dwellers alike to stay informed and protected. Remember, smart sun safety starts with understanding the UV Index!

Hourly UV Index in Fort Collins

Throughout the day, the UV Index displayed a dynamic pattern, peaking at an intense 12 around 1 PM. Starting off gently at 1 by 7 AM, it climbed steadily, reaching 9 by 11 AM, a clear sign to take precautions. As the sun approached its zenith, the index swelled to its maximum at 12 PM, emphasizing the importance of sun safety. Following the midday peak, the index gradually decreased, dropping to 9 by 3 PM, then tapering off further to 2 by 6 PM and 1 by 7 PM. This data underscores the significance of shielding oneself from the sun's harmful rays during the day, especially when the UV Index is at its highest.

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
Time	UVI	Category	Time to Burn
07:00	1	low	45 min
08:00	2	low	45 min
09:00	4	moderate	30 min
10:00	7	high	25 min
11:00	9	very high	15 min
12:00	11	extreme	10 min
13:00	12	extreme	10 min
14:00	11	extreme	10 min
15:00	9	very high	15 min
16:00	6	high	25 min
17:00	4	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Fort Collins

Throughout the year, UV levels exhibit significant seasonal variations, with high-risk months occurring from March to August, when the UV Index consistently reaches very high to extreme levels. April and May display peak values of 11, while June and July escalate to 12, indicating a critical need for sun protection during these times. Visitors and residents should exercise caution, especially during peak sunlight hours, by wearing protective clothing, applying broad-spectrum sunscreen, and seeking shade to minimize the risk of skin damage. As autumn approaches, the UV Index gradually decreases, returning to moderate levels in November and December, providing a more comfortable sun exposure environment.

Monthly Maximum UV Index for Fort Collins, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Fort Collins. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.

Data source: Statistical UV Index data for Fort Collins, based on information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

Compare Fort Collins UV Index with Other United States Cities

The table above highlights how UV exposure in Fort Collins compares to other major locations across United States. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.

Fort Collins's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Chicago UVI	3	4	6	8	9	10	10	9	8	6	4	2
Brooklyn UVI	3	5	6	8	10	10	9	9	8	6	4	2
New York City UVI	3	5	6	8	10	10	9	9	8	6	4	2
Los Angeles UVI	4	6	8	9	10	11	11	10	10	7	5	4
Fort Collins	4	6	8	11	11	12	12	11	9	6	4	3
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5