Last updated: August 1, 2025
Understanding the UV Index is crucial for residents of Pleasanton, as it provides vital information on the strength of ultraviolet radiation from the sun. Being aware of these levels can significantly reduce the risk of sunburn and safeguard your long-term skin health. With Pleasanton's climate characterized by warm summers and moderate winters, the peaks in UV exposure—especially around midday—can reach a maximum of 10, posing increased risks for outdoor activities. Staying informed about the UV Index not only helps you enjoy the beautiful California sunshine safely but also encourages healthier habits when it comes to sun protection.
Throughout the day, the UV Index exhibits a remarkable rise, peaking at 10 between 12:00 PM and 2:00 PM, indicating a high risk of harm from unprotected sun exposure. Starting the morning at a mere 1 at 7:00 AM, the index steadily climbs as the sun ascends, hitting 5 by 10:00 AM and rapidly accelerating to 8 by 11:00 AM. After reaching its zenith at noon, the readings gradually decline through the afternoon, dropping to 4 by 5:00 PM and falling further to 1 by 7:00 PM. It's clear that careful sun protection is essential during the midday hours when the sun's strength is at its most intense.
| 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 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 10 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
Throughout the year, the UV Index experiences notable variations, with the highest risk months occurring from April to August. During this period, the UV Index peaks at 11 in June and July, categorizing these months as having extreme exposure levels with a burn time of just 10 minutes. In contrast, the lowest risk months are January and December, where the UV Index remains at 3, indicating a moderate risk with a burn time of 30 minutes. Visitors and residents are strongly advised to take precautions during peak months by applying sunscreen, wearing protective clothing, and seeking shade, particularly between 10 a.m. and 4 p.m. to minimize the risk of sunburn and skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chicago UVI | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| Brooklyn UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| New York City UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| Pleasanton | 3 | 5 | 7 | 9 | 10 | 11 | 11 | 10 | 9 | 7 | 4 | 3 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |