UV Index for Portola Valley, CA

Current Portola Valley UV Index

0 (Low)

Last Updated 57 minutes ago

Hourly Portola Valley UV Index

The hourly Portola Valley, CA UV Index forecast for Monday, September 15th, 2025.

5 Day Hourly Portola Valley UV Index Forecast

Last Updated 8 hours ago

The UV index forecast for the next five days in Portola Valley, CA has no days reaching the extreme level and 2 days reaching the high or very high levels. The peak UV intensity in Portola Valley over the next five days will be 7.7 on Monday, September 15th at 1:00 pm.

The UV index forecast for Monday, September 15th in Portola Valley, CA is below.

Time UV Index Risk
8pm 0
Low
9pm 0
Low
10pm 0
Low
11pm 0
Low

The UV index forecast for Tuesday, September 16th in Portola Valley, 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 1.2
Low
10am 2.8
Low
11am 4.9
Moderate
12pm 6.6
High
1pm 7.4
High
2pm 7
High
3pm 5.5
Moderate
4pm 3.5
Moderate
5pm 1.6
Low
6pm 0.5
Low
7pm 0
Low
8pm 0
Low
9pm 0
Low
10pm 0
Low
11pm 0
Low

The UV index forecast for Wednesday, September 17th in Portola Valley, 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 1.2
Low
10am 2.9
Low
11am 5
Moderate
12pm 5.4
Moderate
1pm 5.7
Moderate
2pm 5.5
Moderate
3pm 3.8
Moderate
4pm 2.4
Low
5pm 1
Low
6pm 0.3
Low
7pm 0
Low
8pm 0
Low
9pm 0
Low
10pm 0
Low
11pm 0
Low

The UV index forecast for Thursday, September 18th in Portola Valley, 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 0.2
Low
9am 0.6
Low
10am 2
Low
11am 2.8
Low
12pm 2.8
Low
1pm 4.7
Moderate
2pm 3.1
Moderate
3pm 1
Low
4pm 0.9
Low
5pm 0.4
Low
6pm 0.2
Low
7pm 0
Low
8pm 0
Low
9pm 0
Low
10pm 0
Low
11pm 0
Low

The UV index forecast for Friday, September 19th in Portola Valley, 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