UV Index for Mercer Island, WA

Current Mercer Island UV Index

0 (Low)

Last Updated 39 minutes ago

Hourly Mercer Island UV Index

The hourly Mercer Island, WA UV Index forecast for Monday, September 15th, 2025.

5 Day Hourly Mercer Island UV Index Forecast

Last Updated 11 hours ago

The UV index forecast for the next five days in Mercer Island, WA has no days reaching the extreme level and no days reaching the high or very high levels. The peak UV intensity in Mercer Island over the next five days will be 5.3 on Wednesday, September 17th at 1:00 pm.

The UV index forecast for Monday, September 15th in Mercer Island, WA is below.

Time UV Index Risk
11pm 0
Low

The UV index forecast for Tuesday, September 16th in Mercer Island, WA 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 0.8
Low
10am 2
Low
11am 3.3
Moderate
12pm 4.4
Moderate
1pm 4.9
Moderate
2pm 4.6
Moderate
3pm 3.7
Moderate
4pm 2.4
Low
5pm 1.1
Low
6pm 0.4
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 Mercer Island, WA 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 0.9
Low
10am 2.1
Low
11am 3.5
Moderate
12pm 4.7
Moderate
1pm 5.3
Moderate
2pm 5
Moderate
3pm 3.9
Moderate
4pm 2.5
Low
5pm 1.2
Low
6pm 0.4
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 Mercer Island, WA 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 0.8
Low
10am 1.8
Low
11am 3.3
Moderate
12pm 4.5
Moderate
1pm 5
Moderate
2pm 4.6
Moderate
3pm 3.7
Moderate
4pm 2.4
Low
5pm 1.1
Low
6pm 0.4
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 Mercer Island, WA is below.

Time UV Index Risk
12am 0
Low
1am 0
Low
2am 0
Low
3am 0
Low
4am 0
Low
5am 0
Low