UV Index in Rancho Cucamonga, United States

Last updated: July 2, 2025

In Rancho Cucamonga, understanding the UV Index is crucial for protecting your skin and overall health, especially as the sun shines brightly in this Mediterranean climate. With UV levels peaking at a striking 11 at noon, awareness of these radiation levels can greatly contribute to sunburn prevention and long-term skin health. As you enjoy outdoor activities in this vibrant city, knowing when to seek shade and apply sunscreen based on the UV Index can make all the difference in safeguarding your skin against harmful rays.

Hourly UV Index in Rancho Cucamonga

At dawn, the UV Index starts at a gentle 1 by 07:00, indicating minimal exposure risk. As the sun climbs higher, the intensity rises sharply, reaching a maximum of 11 between 12:00 and 13:00—a time when protective measures are crucial. The peak UV Index highlights the importance of sun safety, as conditions can be particularly harsh. The afternoon sees a gradual decline, dipping to 8 by 15:00 and further decreasing to 3 by 17:00. As evening approaches, the index wanes to a mellow 1 by 19:00, suggesting a return to safer exposure levels. Keep in mind that tracking the UV Index throughout the day can help protect your skin from harmful rays!

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	11	extreme	10 min
14:00	10	very high	15 min
15:00	8	very high	15 min
16:00	6	high	25 min
17:00	3	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Rancho Cucamonga

During the year, UV Index values show significant seasonal variation, peaking in the summer months. High-risk months for UV exposure include March through August, particularly notable in June and July, where the UV Index reaches an extreme level of 12 and 11, respectively, with a burn time of only 10 minutes. Visitors and residents are advised to take necessary precautions during these months, such as wearing protective clothing, using broad-spectrum sunscreen, and limiting sun exposure, especially between 10 AM and 4 PM. As UV levels decrease from September onward, with moderate levels returning in the winter months of November and December, maintaining sun safety remains important, especially during high-exposure periods.

Monthly Maximum UV Index for Rancho Cucamonga, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Rancho Cucamonga. 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 Rancho Cucamonga, 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 Rancho Cucamonga UV Index with Other United States Cities

The table above highlights how UV exposure in Rancho Cucamonga 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.

Rancho Cucamonga'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
Rancho Cucamonga	4	6	8	10	10	12	11	10	10	7	5	4
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5