UV Index in Cat Ba, Vietnam

Last updated: July 2, 2025

In Cat Ba, Vietnam, being aware of the UV Index is crucial for protecting your skin while enjoying the island's stunning landscapes. Understanding UV levels helps you prevent sunburn and maintain long-term skin health, especially in a region characterized by a Cwa climate that features significant daylight hours and intense sun exposure. On a typical day, UV levels can soar to dangerous heights, peaking at 13 around midday, making it essential for both locals and visitors to stay informed about the daily UV forecast and take necessary precautions against the sun’s harmful rays.

Hourly UV Index in Cat Ba

As the day unfolds, the UV Index reveals a dramatic rise in sun intensity. Starting at a mild 2 at 7:00 AM, the index quickly escalates to a moderate 4 by 8:00 AM. The real heat hits at 9:00 AM with a 7, peaking at an intense 10 around 10:00 AM. By 11:00 AM, the UV Index reaches its zenith at 13, remaining high until 12:00 PM. The numbers dip slightly to 11 at 1:00 PM and then to 9 by 2:00 PM, before gently declining to 6 at 3:00 PM. As the sun begins to set, the index falls steadily to 3 at 4:00 PM, and drops to 1 by 5:00 PM, maintaining that low level into the evening with a final 0 at 7:00 PM. This data underscores the need for sun protection during peak hours, particularly from 10 AM to 1 PM when the sun's rays are most powerful!

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	2	low	45 min
08:00	4	moderate	30 min
09:00	7	high	25 min
10:00	10	very high	15 min
11:00	13	extreme	10 min
12:00	13	extreme	10 min
13:00	11	extreme	10 min
14:00	9	very high	15 min
15:00	6	high	25 min
16:00	3	moderate	30 min
17:00	1	low	45 min
18:00	1	low	45 min
19:00	0	low	45 min

Monthly UV Index Trends in Cat Ba

Throughout the year, UV Index levels fluctuate significantly, with the highest risk months being from March to October, where values consistently reach extreme levels of 10 or above. Specifically, April, June, July, August, and September all see a peak UV Index of 13, necessitating only 10 minutes of exposure before potential skin damage occurs. In contrast, the UV Index is at its lowest in December and January, with values of 7 and 8, respectively, making burn times of 25 and 15 minutes more tolerable. Visitors and residents are strongly advised to take precautionary measures during the high-risk months by wearing sunscreen, protective clothing, and seeking shade to minimize skin damage. Stay vigilant to ensure your safety while enjoying outdoor activities!

Monthly Maximum UV Index for Cat Ba, Vietnam

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Cat Ba. 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 Cat Ba, 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 Cat Ba UV Index with Other Vietnam Cities

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

Cat Ba's solar exposure compared to other cities in Vietnam. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Hanoi UVI	8	10	12	12	13	12	12	13	13	11	9	7
Cat Ba	8	10	12	13	12	13	13	13	13	11	9	7
Haiphong UVI	8	10	12	13	12	13	13	13	13	11	9	7
Da Nang UVI	10	12	14	15	14	13	14	14	13	12	10	9
Ho Chi Minh City UVI	10	13	15	14	14	12	13	14	13	13	11	10
Bien Hoa UVI	10	14	15	15	14	13	14	14	13	12	11	10