San Francisco UV index in January
Typical ultraviolet levels for San Francisco during January, from the past year of data.
Low
San Francisco
Low UV. You can safely enjoy being outside; the sun's rays are not very strong.
1.9
UV Index
January average UTC
Low
Moderate
High
Very High
Extreme
January UV
1.9194
Risk level
Low
Yearly peak
10.8042
Peak month
July
San Francisco UV index — monthly trend
Average UV index by month over the past year, with January highlighted.
Visiting San Francisco in January?
In January, San Francisco's typical UV index is about 1.9194 — a low risk level. Low UV. You can safely enjoy being outside; the sun's rays are not very strong.
Across the year, San Francisco sees the strongest UV in Summer, peaking around 10.8042 in July. Plan sun protection accordingly.