UV Index in Napa, California
Sunday
08/17
Current UV Index:
7.14
Very high risk of harm
A UV Index of 8 to 10 means there is a very high risk of harm from unprotected sun exposure. Take extra precautions as unprotected skin and eyes are vulnerable and can burn quickly.
UV Index Scale
0
- 2
Low risk of harm
A UV index of 0 to 2 means that the danger from the Sun's UV rays to the average person is low.
3
- 5
Medium risk of harm
A UV index of 3 to 5 means a moderate risk of harm from unprotected sun exposure.
6
- 7
High risk of harm
A UV Index of 6 to 7 means a high risk of harm from unprotected sun exposure. Skin and eye protection is essential.
8
- 10
Very high risk of harm
A UV Index of 8 to 10 means there is a very high risk of harm from unprotected sun exposure. Take extra precautions as unprotected skin and eyes are vulnerable and can burn quickly.
11+
Risk of dangerous harm
A UV Index of 11 or higher means an extremely high risk of harm from unprotected sun exposure. Take every precaution as unprotected skin and eyes can burn in minutes.
Hourly UV Index Forecast
Wear sunglasses on sunny days. In winter, reflection can double the intensity of UV rays.
If you burn easily, cover up and use sunscreen.
If you burn easily, cover up and use sunscreen.
1-2
Low
3-5
Medium
6-7
High
8-10
Very high
11+
Extremely high
Daily UV Index Forecast
Today
08/17
16o
/
25o
9.11
Very high risk of harm
Mon
08/18
11o
/
29o
9.25
Very high risk of harm
Tue
08/19
11o
/
29o
9.47
Very high risk of harm
Wed
08/20
12o
/
34o
9.58
Very high risk of harm
Thu
08/21
15o
/
36o
9.14
Very high risk of harm
Fri
08/22
14o
/
33o
10
Very high risk of harm
Sat
08/23
14o
/
34o
10
Very high risk of harm
Sun
08/24
13o
/
30o
10
Very high risk of harm
08/17/2025
25o
Clear sky
16oC
/
25oC
| Real feel
25oC
0% rain
|
0 mm
60
0
5.0
08/15/2025
1202
0
4.6
08/15/2025
1605
0
4.4
08/15/2025
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