UV Index for St. Helena, CA

Current St. Helena UV Index

0 (Low)

Last Updated 42 minutes ago

Hourly St. Helena UV Index

The hourly St. Helena, CA UV Index forecast for Wednesday, November 5th, 2025.

5 Day Hourly St. Helena UV Index Forecast

Last Updated 21 hours ago

The UV index forecast for the next five days in St. Helena, CA has no days reaching the extreme level and no days reaching the high or very high levels. The peak UV intensity in St. Helena over the next five days will be 3.5 on Thursday, November 6th at 12:00 pm.

The UV index forecast for Wednesday, November 5th in St. Helena, CA is below.

Time UV Index Risk
8am 0
Low
9am 0.2
Low
10am 0.2
Low
11am 0.4
Low
12pm 0.8
Low
1pm 0.6
Low
2pm 0.5
Low
3pm 0.3
Low
4pm 0.1
Low
5pm 0
Low
6pm 0
Low
7pm 0
Low
8pm 0
Low
9pm 0
Low
10pm 0
Low
11pm 0
Low

The UV index forecast for Thursday, November 6th in St. Helena, CA is below.

Time UV Index Risk
12am 0
Low
1am 0
Low
2am 0
Low
3am 0
Low
4am 0
Low
5am 0
Low
6am 0
Low
7am 0
Low
8am 0.3
Low
9am 1
Low
10am 2
Low
11am 3
Moderate
12pm 3.5
Moderate
1pm 3.3
Moderate
2pm 2.4
Low
3pm 1.3
Low
4pm 0.4
Low
5pm 0
Low
6pm 0
Low
7pm 0
Low
8pm 0
Low
9pm 0
Low
10pm 0
Low
11pm 0
Low

The UV index forecast for Friday, November 7th in St. Helena, CA is below.

Time UV Index Risk
12am 0
Low
1am 0
Low
2am 0
Low
3am 0
Low
4am 0
Low
5am 0
Low
6am 0
Low
7am 0
Low
8am 0
Low
9am 0.2
Low
10am 0.3
Low
11am 0.6
Low
12pm 0.7
Low
1pm 0.9
Low
2pm 0.9
Low
3pm 0.6
Low
4pm 0.2
Low
5pm 0
Low
6pm 0
Low
7pm 0
Low
8pm 0
Low
9pm 0
Low
10pm 0
Low
11pm 0
Low

The UV index forecast for Saturday, November 8th in St. Helena, CA is below.

Time UV Index Risk
12am 0
Low
1am 0
Low
2am 0
Low
3am 0
Low
4am 0
Low