UV Index in Union City, United States

Last updated: May 3, 2025

In Union City, understanding the UV Index is crucial for protecting your skin from harmful ultraviolet radiation. The UV levels in our region can reach a maximum of 10 around midday, making it essential to be aware of sun exposure to prevent sunburn and maintain long-term skin health. With a Dfa climate that offers abundant sunshine, residents face significant UV exposure risks, especially during peak hours. By staying informed about the UV Index, you can enjoy the outdoors safely while keeping your skin protected.

Hourly UV Index in Union City

The UV Index data reveals a striking progression throughout the day. Early risers at 07:00 and 08:00 will experience a low UV Index of 1, making it a safe window for outdoor activities. However, as the day unfolds, 9:00 sees a jump to 3, which hints at increasing sun intensity. The real peak occurs between 12:00 and 14:00, where the UV Index hits its maximum at 10—a critical period for sun exposure, urging caution for those outdoors. As the afternoon transitions to evening, the index gradually drops, settling back to a more manageable 1 by 19:00. This data highlights the importance of sun safety during the midday hours, as the sun's rays can be particularly harsh.

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	1	low	45 min
09:00	3	moderate	30 min
10:00	4	moderate	30 min
11:00	7	high	25 min
12:00	9	very high	15 min
13:00	10	very high	15 min
14:00	10	very high	15 min
15:00	9	very high	15 min
16:00	7	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 Union City

Throughout the year, UV exposure varies significantly, peaking during late spring and summer months. High-risk months for UV exposure are April through September, where the UV Index frequently reaches levels classified as very high; particularly notable are May, June, and July, when it consistently hits a maximum of 10. Visitors and residents are advised to take precautions during these months, with burn times dramatically reduced to as little as 15 minutes. In contrast, January, February, and November present moderate UV levels, and December has a low index, making sun safety measures less critical during these months. To protect against skin damage, it is essential to wear sunscreen, seek shade, and wear protective clothing, especially between peak months of April and September.

Monthly Maximum UV Index for Union City, United States

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

The table above highlights how UV exposure in Union City 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.

Union City'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
Union City	3	5	6	9	10	10	10	9	8	6	4	2
Los Angeles UVI	4	6	8	9	10	11	11	10	10	7	5	4
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5