UV Index for Port St. John, FL

Current Port St. John UV Index

8.1 (Very High)

Last Updated 44 minutes ago

Hourly Port St. John UV Index

The hourly Port St. John, FL UV Index forecast for Tuesday, September 16th, 2025.

5 Day Hourly Port St. John UV Index Forecast

Last Updated 22 hours ago

The UV index forecast for the next five days in Port St. John, FL has no days reaching the extreme level and 2 days reaching the high or very high levels. The peak UV intensity in Port St. John over the next five days will be 9.5 on Tuesday, September 16th at 1:00 pm.

The UV index forecast for Tuesday, September 16th in Port St. John, FL is below.

Time UV Index Risk
1pm 9.5
Very High
2pm 9.3
Very High
3pm 6.6
High
4pm 3.3
Moderate
5pm 1.4
Low
6pm 0.4
Low
7pm 0.1
Low
8pm 0
Low
9pm 0
Low
10pm 0
Low
11pm 0
Low

The UV index forecast for Wednesday, September 17th in Port St. John, FL 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 1
Low
10am 2.6
Low
11am 4.5
Moderate
12pm 6
High
1pm 6.8
High
2pm 5.8
Moderate
3pm 4.4
Moderate
4pm 3.4
Moderate
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 Port St. John, FL 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 0.1
Low
10am 0.2
Low
11am 0.3
Low
12pm 0.4
Low
1pm 0.6
Low
2pm 0.6
Low
3pm 0.5
Low
4pm 0.4
Low
5pm 0.2
Low
6pm 0.1
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 Port St. John, FL 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