UV Index in Keystone, United States

Last updated: June 2, 2025

Understanding the UV Index is crucial for residents and visitors in Keystone, United States, where the sun's rays can be deceptively intense, especially during the summer months. With a Dfc climate, characterized by cool summers and ample sunshine, awareness of UV levels is vital for preventing sunburn and protecting long-term skin health. The UV Index here peaks at 14 around midday, signaling a risk of harm from unprotected sun exposure. By keeping an eye on these levels, you can enjoy everything Keystone has to offer while safeguarding your skin from the damaging effects of UV radiation.

Hourly UV Index in Keystone

As the day unfolds, the UV Index peaks dramatically, reminding us to take heed of the sun’s intensity. Starting at a safer 1 at 7:00 AM, it rises steadily, hitting 3 by 8:00 AM and climbing to a moderate 5 by 9:00 AM. The sun begins to showcase its strength as it reaches 8 at 10:00 AM, before soaring to a critical 11 by 11:00 AM. The highest point of the day arrives at 13 and 14 between 12:00 PM and 1:00 PM, marking the most dangerous hours for sun exposure. As afternoon progresses, the intensity slightly wanes, dropping to 11 by 3:00 PM and then easing further to 8 at 4:00 PM. As the sun begins to lower, the UV Index falls to 5 by 5:00 PM, and concludes the day at a gentle 1 by 7:00 PM. Remember to protect your skin during those peak hours!

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.
TimeUVICategoryTime to Burn
07:001low45 min
08:003moderate30 min
09:005moderate30 min
10:008very high15 min
11:0011extreme10 min
12:0013extreme10 min
13:0014extreme10 min
14:0013extreme10 min
15:0011extreme10 min
16:008very high15 min
17:005moderate30 min
18:002low45 min
19:001low45 min

Monthly UV Index Trends in Keystone

Throughout the year, UV exposure levels fluctuate significantly, with high-risk months typically occurring from March through September. During these months, the UV Index peaks, reaching extreme levels of 12 to 14 in April, May, June, and July, where the recommended burn time is as little as 10 minutes. Conversely, the UV Index remains lower during the winter months, with January and December registering a moderate Index of 4, allowing for a safer burn time of 30 minutes. Visitors and residents are advised to exercise caution and protection, particularly between March and September, by wearing sunscreen, protective clothing, and sunglasses during peak sunlight hours to minimize the risk of sunburn and long-term skin damage.

Monthly Maximum UV Index for Keystone, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Keystone. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec469121314131210753
Data source: Statistical UV Index data for Keystone, 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 Keystone UV Index with Other United States Cities

The table above highlights how UV exposure in Keystone 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.
Keystone's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
 JanFebMarAprMayJunJulAugSepOctNovDec
Chicago UVI34689101098642
Brooklyn UVI35681010998642
New York City UVI35681010998642
Los Angeles UVI46891011111010754
Houston UVI589111112121110975
Keystone469121314131211754