On this page, you can find the current UV Index and hourly 5 day UV Index forecast for Alto, Marin County, California (CA). The Ultraviolet Index forecast, which measures the radiation from the sun that reaches the Earth's surface is updated daily.
(Updated 49 minutes ago.)
As of 2:49 PM PDT, the UV Index in Alto, CA is 10 (Very High).
The UV Index is expected to fall sharply
to 8.3 (still Very High) between 3:00 PM - 4:00 PM PDT today.
UV Index Data sourced from the NOAA.
As of 2:49 PM PDT today in Alto, CA, the UV Index is currently at a very high level of 10. As the day progresses, the UV index is expected to fall as the sun sets.
It will return to high levels at 4:00 PM and then drop to low levels again from 6:00 PM onwards. As the day transitions into the night, the UV Index will drop back down to 0 at 8:00 PM.
| Time Range | UV Index | Risk |
|---|---|---|
| 6:00 AM - 9:00 AM (PDT) | 0 - 1.1 | Low |
| 9:00 AM - 11:00 AM | 2.7 - 5 | Moderate |
| 11:00 AM - 4:00 PM | 7.5 - 10.4 | Very High |
| 4:00 PM - 5:00 PM | 6 | High |
| 5:00 PM - 6:00 PM | 3.5 | Moderate |
| 6:00 PM - 12:00 AM | 0 - 1.6 | Low |
| Time Range | UV Index | Risk |
|---|---|---|
| 12:00 AM - 9:00 AM (PDT) | 0 - 1.2 | Low |
| 9:00 AM - 11:00 AM | 2.8 - 5 | Moderate |
| 11:00 AM - 4:00 PM | 7.5 - 10.3 | Very High |
| 4:00 PM - 5:00 PM | 5.9 | High |
| 5:00 PM - 6:00 PM | 3.4 | Moderate |
| 6:00 PM - 12:00 AM | 0 - 1.6 | Low |
| Time | UV Index | Risk |
|---|---|---|
| 2:00 PM - 3:00 PM (Now, PDT) | 10 | Very High |
| 3:00 PM - 4:00 PM | 8.3 | Very High |
| 4:00 PM - 5:00 PM | 6 | High |
| 5:00 PM - 6:00 PM | 3.5 | Moderate |
| 6:00 PM - 7:00 PM | 1.6 | Low |
| 7:00 PM - 8:00 PM | 0.5 | Low |
| 8:00 PM - 9:00 PM | 0 | Low |
| 9:00 PM - 10:00 PM | 0 | Low |
| 10:00 PM - 11:00 PM | 0 | Low |
| 11:00 PM - 12:00 AM | 0 | Low |