Cali UV index in September
Typical ultraviolet levels for Cali during September, from the past year of data.
Extreme
Cali
Extreme UV. Avoid sun exposure, seek shade, and use comprehensive protection: clothing, sunscreen, and a hat.
15.4
UV Index
September average
Low
Moderate
High
Very High
Extreme
September UV
15.3757
Risk level
Extreme
Yearly peak
15.5098
Peak month
April
Cali UV index — monthly trend
Average UV index by month over the past year, with September highlighted.
Visiting Cali in September?
In September, Cali's typical UV index is about 15.3757 — a extreme risk level. Extreme UV. Avoid sun exposure, seek shade, and use comprehensive protection: clothing, sunscreen, and a hat.
Across the year, Cali sees the strongest UV in Spring, peaking around 15.5098 in April. Plan sun protection accordingly.
