Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Merlo, Argentina, where the climate features warm summers and moderate winters, but still presents significant UV exposure risks. Being aware of UV levels helps in preventing sunburn and maintaining long-term skin health, particularly since midday values can reach up to 4, highlighting the importance of taking precautions. As you enjoy the stunning landscapes of Merlo, be mindful of the sun’s intensity, especially during peak hours, to ensure a safe and enjoyable outdoor experience.
The UV Index throughout the day presents an interesting pattern that reflects the sun's intensity. Starting off at 0 at 7:00 AM, the day awakens with minimal UV exposure. As the sun rises, the index gradually climbs, reaching 1 at 8:00 AM and 9:00 AM. By 10:00 AM, it hits 2, indicating a slight need for sun protection. The real peak occurs between 12:00 PM and 1:00 PM, where the index soars to 4 — the ideal time to seek shade or slather on sunscreen. After this midday high, the UV levels gently decline to 3 by 2:00 PM and 3:00 PM, before tapering off to 1 by late afternoon. Finally, as the sun sets around 7:00 PM, the UV Index dips back to 0, signaling the end of the day’s sun exposure. Whether planning outdoor activities or simply enjoying the sunshine, monitoring these fluctuations can help ensure a safe experience.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 0 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 1 | low | 45 min |
| 10:00 | 2 | low | 45 min |
| 11:00 | 3 | moderate | 30 min |
| 12:00 | 4 | moderate | 30 min |
| 13:00 | 4 | moderate | 30 min |
| 14:00 | 3 | moderate | 30 min |
| 15:00 | 3 | moderate | 30 min |
| 16:00 | 1 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
Throughout the year, UV exposure varies significantly, with the highest risk months typically being from November to March, where the UV Index remains in the extreme category, peaking at 14 in both January and December. During these months, the burn time is as short as 10 minutes, emphasizing the need for heightened caution. Transitioning into April and August, UV levels drop to a high category of 7 and 6, respectively, with burn times extending to 25 minutes. As summer arrives, UV levels moderate slightly, with May to July reflecting a range of 3 to 5 and a moderate risk, allowing for longer exposure times. However, September and October see a return to very high exposure, underscoring the need for protective measures as burn times decrease again to 15 minutes. Residents and visitors are advised to check the UV index daily and employ effective sun safety strategies, such as seeking shade, wearing protective clothing, and applying sunscreen, especially during the high-risk months.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Merlo | 14 | 12 | 11 | 7 | 5 | 3 | 4 | 6 | 8 | 10 | 13 | 14 |
| Buenos Aires UVI | 14 | 13 | 11 | 7 | 5 | 4 | 4 | 6 | 8 | 10 | 13 | 14 |
| Rosario UVI | 14 | 13 | 11 | 8 | 5 | 4 | 4 | 6 | 8 | 11 | 13 | 14 |
| Mendoza UVI | 15 | 14 | 12 | 8 | 6 | 4 | 5 | 6 | 9 | 12 | 14 | 15 |
| Cordoba UVI | 15 | 13 | 12 | 9 | 6 | 4 | 5 | 7 | 9 | 12 | 14 | 15 |
| San Miguel de Tucuman UVI | 15 | 14 | 13 | 10 | 7 | 5 | 6 | 7 | 10 | 13 | 15 | 15 |