UV Index in Hagatna, Guam

Last updated: May 3, 2025

Awareness of the UV Index is crucial in Hagatna, Guam, where tropical sunshine often leads to increased risks of harmful UV exposure. Understanding UV levels not only helps in preventing sunburn but is also essential for maintaining long-term skin health. With a climate categorized as tropical, Hagatna experiences high UV readings throughout the day, peaking at a staggering UV Index of 13 around noon. This makes it imperative for residents and visitors alike to stay informed about daily UV levels and take appropriate sun protection measures.

Hourly UV Index in Hagatna

As the sun climbs higher, the UV Index reaches its peak intensity around 12:00 PM, soaring to a striking 13—a clear signal for outdoor enthusiasts to take precautions. The morning hours start gently, with a low of 1 at 07:00 AM, gradually escalating to 6 by 09:00 AM and hitting 9 at 10:00 AM. By 11:00 AM, the sun begins to assert itself with a 12. However, as the afternoon progresses, the UV intensity starts to wane, dropping to 10 at 2:00 PM, and tapering off to a mere 2 by 5:00 PM. As daylight diminishes, the UV Index dwindles to 0 by 7:00 PM, inviting a much-needed respite from the sun’s relentless rays. Always be vigilant and 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.
Time	UVI	Category	Time to Burn
07:00	1	low	45 min
08:00	3	moderate	30 min
09:00	6	high	25 min
10:00	9	very high	15 min
11:00	12	extreme	10 min
12:00	13	extreme	10 min
13:00	13	extreme	10 min
14:00	10	very high	15 min
15:00	7	high	25 min
16:00	4	moderate	30 min
17:00	2	low	45 min
18:00	1	low	45 min
19:00	0	low	45 min

Monthly UV Index Trends in Hagatna

The UV Index exhibits extreme levels throughout the year, with consistent ratings between 11 and 15 from January to September. The highest UV Index of 15 occurs in March, April, and September, marking these as the high-risk months for sun exposure. Visitors and residents should be particularly cautious during these months, as the burn time is as short as 10 minutes across all months listed, indicating a significant risk of skin damage. To ensure safety, it is crucial to use adequate sun protection, such as broad-spectrum sunscreen, protective clothing, and seeking shade, especially during peak sun hours.

Monthly Maximum UV Index for Hagatna, Guam

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

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

Hagatna's solar exposure compared to other cities in Guam. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Hagatna	11	13	15	15	13	14	14	14	15	13	12	11
Barrigada Village UVI	11	13	15	15	13	14	14	14	15	13	12	11
Mangilao Village UVI	11	13	15	15	13	14	14	14	15	13	12	11
Tamuning-Tumon-Harmon Village UVI	11	13	15	15	13	14	14	14	15	13	12	11
Yigo Village UVI	11	13	15	15	13	14	14	14	15	13	12	11
Dededo Village UVI	11	13	15	15	13	14	14	14	15	13	12	11