UV Index in Houston, United States

Last updated: June 2, 2025

In Houston, United States, being aware of the UV Index is crucial for protecting your skin against harmful ultraviolet rays. Understanding UV levels helps prevent sunburn and promotes skin health, essential for everyone, especially in a city known for its warm, humid climate and prolonged sun exposure. With peak UV levels reaching as high as 11 from late morning to early afternoon, it's vital for Houstonians to take proactive measures to safeguard their skin. From seeking shade to applying sunscreen, awareness of the UV Index can make a significant difference in your daily outdoor activities.

Hourly UV Index in Houston

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 Houston

Throughout the year, UV Index levels exhibit significant seasonal variations, with high-risk months highlighted between March and August. During this period, the UV Index often reaches very high to extreme levels, particularly in May, June, and July, where it peaks at 11 and suggests a burn time of as little as 10 minutes. Visitors and residents are advised to take precautionary measures, such as wearing sunscreen, protective clothing, and seeking shade during peak hours. In contrast, the lower UV levels in January, December, and November present a moderate risk, with recommended exposure times of 30 and 25 minutes. As the year progresses, it’s crucial to stay informed about these UV changes and adjust sun safety practices accordingly.

Monthly Maximum UV Index for Houston, United States

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

The table above highlights how UV exposure in Houston 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.

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