Last updated: June 2, 2025
In Alfenas, Brazil, awareness of the UV Index is crucial for maintaining skin health and preventing painful sunburns. Understanding the fluctuating levels of ultraviolet radiation throughout the day can help residents and visitors alike take proactive measures against potential skin damage. With a Cwa climate, Alfenas experiences significant UV exposure, especially during the late morning and early afternoon hours when the index peaks at 7 around noon. By staying informed about the UV Index, you can enjoy the sunny days while protecting your skin.
At dawn, the UV Index starts off low, with a maximum of 1 at 07:00 and 08:00. As the sun rises higher, it reaches 3 by 09:00, before climbing to a peak of 7 at 12:00. This midday intensity signifies a need for sun protection, especially during the height of the day when UV exposure is most potent. The index begins to decline in the afternoon, dropping to 5 at 14:00 and settling back to 1 by 17:00. By 18:00 and into the evening, the UV Index sharply drops to 0, marking a safe time to enjoy outdoor activities without the risk of sunburn. Stay sun-safe!
Time | UVI | Category | Time to Burn |
---|---|---|---|
07:00 | 1 | low | 45 min |
08:00 | 1 | low | 45 min |
09:00 | 3 | moderate | 30 min |
10:00 | 5 | moderate | 30 min |
11:00 | 6 | high | 25 min |
12:00 | 7 | high | 25 min |
13:00 | 6 | high | 25 min |
14:00 | 5 | moderate | 30 min |
15:00 | 3 | moderate | 30 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 |
The UV Index shows significant seasonal variation, with the highest readings occurring from January to April, where the index reaches an extreme 16. These months pose a high risk for sunburn, with a critical 10-minute burn time. After April, the index slightly decreases, but remains very high in May (8) and July (8), and high in June (7). As summer transitions into fall, the UV Index fluctuates but remains concerning, especially in September (12) and October (14), both categorized as extreme, again allowing only a short 10-minute exposure without protection. The end of the year is marked by high indices once more, peaking in December at 16. Visitors and residents are strongly advised to take protective measures against UV exposure, particularly during these high-risk months to minimize the risk of sunburn and long-term 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 |
Alfenas | 16 | 16 | 13 | 11 | 8 | 7 | 8 | 10 | 12 | 14 | 15 | 16 |
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 |