Last updated: July 2, 2025
Understanding the UV Index is crucial for anyone enjoying the sunny landscapes of Costa Rica and Brazil. With its tropical climate and high UV exposure throughout the year, being aware of UV levels helps in effectively preventing sunburn and promoting overall skin health. During peak hours, the UV Index can reach up to 7, indicating a high risk of harm from unprotected sun exposure, especially between 10:00 AM and 2:00 PM. Staying informed not only safeguards your skin but enhances your outdoor experiences, making your time in this beautiful region even more enjoyable.
The UV Index data paints a clear picture of how exposure to ultraviolet rays varies throughout the day. Starting at a low level of 1 at 07:00, the index gradually climbs to peak at 7 from 11:00 to 12:00, indicating the times when sun protection is most crucial. As the afternoon progresses, the index dips to 6 at 13:00, then gently declines to 4 by 14:00. The evening hours see a significant drop, with values falling to 2 at 15:00 and retreating to 1 at 16:00. By nightfall, the UV Index drops to 0 from 18:00 onward, signalling a safe time for outdoor activities without the need for sun protection. Enjoy the sunshine, but be mindful of the peak hours!
Time | UVI | Category | Time to Burn |
---|---|---|---|
07:00 | 1 | low | 45 min |
08:00 | 2 | low | 45 min |
09:00 | 3 | moderate | 30 min |
10:00 | 5 | moderate | 30 min |
11:00 | 7 | high | 25 min |
12:00 | 7 | high | 25 min |
13:00 | 6 | high | 25 min |
14:00 | 4 | moderate | 30 min |
15:00 | 2 | low | 45 min |
16:00 | 1 | low | 45 min |
17:00 | 1 | low | 45 min |
18:00 | 0 | low | 45 min |
19:00 | 0 | low | 45 min |
During the year, UV levels fluctuate significantly, with particularly high-risk months occurring from January to April and September to November. Notably, these months have an extreme UV Index of 15-11, with a very short burn time of just 10 minutes. The UV Index starts to decrease in May and July, where it shifts to a very high and high exposure category, allowing for slightly longer burn times of 15 to 25 minutes. August sees a rise again before returning to extreme levels in September and October. Visitors and residents should take precautionary measures during high UV months: wear sunscreen, protective clothing, and hats, and seek shade when outside, especially during midday hours to reduce the risk of skin damage.
UV Risk Categories
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 |
Costa Rica | 15 | 15 | 13 | 11 | 8 | 6 | 7 | 9 | 11 | 14 | 15 | 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 |