UV Index in Castanhal, Brazil

Last updated: May 3, 2025

In Castanhal, Brazil, awareness of the UV Index is crucial for safeguarding your skin and overall health. With the tropical climate typical to this region, UV exposure can reach dangerously high levels, especially between 10 AM and 2 PM, when the index peaks at 14—a significant risk for sunburn and long-term skin damage. Understanding these levels empowers residents and visitors alike to take proactive measures for sun safety, helping to prevent the harmful effects of ultraviolet radiation while enjoying the abundant sunshine that Castanhal has to offer.

Hourly UV Index in Castanhal

As the sun rises, the UV Index gradually climbs, peaking at 14 around 12:00 PM, indicating a high risk of harm from unprotected sun exposure. From the early morning 1 at 7:00 AM, it swiftly escalates to 6 by 9:00 AM, then surges to its maximum intensity of 13 at 11:00 AM and 1:00 PM. After the midday peak, the UV levels start to decline, dropping to 6 by 3:00 PM, and tapering off to 1 by 5:00 PM. By 7:00 PM, the UV Index falls to 0, ensuring a safe environment for evening activities. For those venturing outdoors, sun safety precautions are essential during the high-risk hours, particularly from 10:00 AM to 2:00 PM.

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	13	extreme	10 min
12:00	14	extreme	10 min
13:00	13	extreme	10 min
14:00	10	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 Castanhal

The UV Index demonstrates significant seasonal variations, with the highest values occurring from January to April, peaking at 16, indicating an extreme exposure category and a mere 10-minute burn time for unprotected skin. Throughout the year, the high-risk months remain consistent, with the UV Index consistently at 13 or above from January to May and returning to 13 from August to December, signifying continued high risk even in the latter part of the year. Visitors and residents are advised to exercise extreme caution during all months, especially from January to April, by applying broad-spectrum sunscreen, wearing protective clothing, and seeking shade to minimize harmful exposure to UV radiation.

Monthly Maximum UV Index for Castanhal, Brazil

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

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

Castanhal's solar exposure compared to other cities in Brazil. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Rio de Janeiro UVI	15	14	13	10	7	6	7	9	11	12	13	15
Sao Paulo UVI	16	15	12	11	8	6	7	9	11	13	14	15
Belo Horizonte UVI	17	16	14	12	9	7	8	10	12	13	14	16
Salvador UVI	14	14	14	13	10	9	9	12	12	15	15	14
Fortaleza UVI	14	14	15	15	13	11	11	12	13	13	13	13
Castanhal	14	15	16	16	14	12	11	13	13	13	13	13