Johnstown, Colorado, United States UV Index Forecast

Find the UV Index forecast for today, tomorrow and the next 15 days for Johnstown, Colorado, United States, The Ultraviolet Index forecast, which measures the radiation from the sun that reaches the Earth's surface is updated hourly.

Current UV Index
10:30 am

Very High8

UV INDEX

Hourly UV Index Forecast for Today
July 25, 2025

0
6 am
0
7 am
2
8 am
4
9 am
5
10 am
8
11 am
9
12 pm
10
1 pm
10
2 pm
8
3 pm
8
4 pm
6
5 pm
4
6 pm
1
7 pm
  • Low
    1-2
  • Moderate
    3-4-5
  • High
    6-7
  • Very High
    8-9-10
  • Xtreme
    11+

As of 10:30 am today in Johnstown, Colorado, United States, the UV Index is currently at a Very High level of 8.

Summary of Hourly UV Index Forecast for Today and Tomorrow in Johnstown, Colorado, United States.

Today

Time Range UV Index Risk
6 am 0
Low
7 am 0
Low
8 am 2
Low
9 am 4
Moderate
10 am 5
Moderate
11 am 8
Very High
12 pm 9
Very High
1 pm 10
Very High
2 pm 10
Very High
3 pm 8
Very High
4 pm 8
Very High
5 pm 6
High
6 pm 4
Moderate
7 pm 1
Low

Tomorrow

Time Range UV Index Risk
6 am 0
Low
7 am 1
Low
8 am 3
Moderate
9 am 5
Moderate
10 am 6
High
11 am 7
High
12 pm 8
Very High
1 pm 9
Very High
2 pm 7
High
3 pm 7
High
4 pm 7
High
5 pm 6
High
6 pm 4
Moderate
7 pm 3
Moderate

Daily Johnstown UV Index Forecast for the next 15 days:

10
25 Jul
9
26 Jul
10
27 Jul
9
28 Jul
9
29 Jul
5
30 Jul
9
31 Jul
9
1 Aug
7
2 Aug
8
3 Aug
8
4 Aug
9
5 Aug
9
6 Aug
9
7 Aug
  • Low
    1-2
  • Moderate
    3-4-5
  • High
    6-7
  • Very High
    8-9-10
  • Xtreme
    11+

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