UV Index in Portola, United States

Last updated: June 2, 2025

In Portola, United States, being aware of the UV Index is crucial for protecting your skin and maintaining overall health. Understanding UV levels helps you take proactive measures against sunburn and long-term skin damage, especially during the peak midday hours when the index can soar to 12. With a Csb climate, Portola experiences varying UV exposure that can catch many off guard, making it essential to stay informed and take appropriate precautions every time the sun shines. Embrace the sun safely by knowing when to seek shade or apply sunscreen, and enjoy the beautiful outdoors of Portola responsibly!

Hourly UV Index in Portola

The UV Index throughout the day showcases a dynamic surge, peaking at an impressive 12 between 1:00 PM and 2:00 PM. The morning starts slowly, with values of 1 at 7:00 AM and climbing to 2 by 8:00 AM. As the sun climbs higher, the index sharply rises, hitting 10 by 11:00 AM and reaching a sizzling 11 at noon. After the midday crescendo, there's a gradual decline, dropping to 9 at 3:00 PM, and eventually settling back to 1 by 7:00 PM. This pattern emphasizes the importance of sun protection during peak hours, especially from 11:00 AM to 2:00 PM, where the risk of harm from UV exposure is at its highest.

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
Time	UVI	Category	Time to Burn
07:00	1	low	45 min
08:00	2	low	45 min
09:00	4	moderate	30 min
10:00	7	high	25 min
11:00	10	very high	15 min
12:00	11	extreme	10 min
13:00	12	extreme	10 min
14:00	11	extreme	10 min
15:00	9	very high	15 min
16:00	7	high	25 min
17:00	4	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Portola

Throughout the year, the UV Index experiences significant fluctuations, peaking during the summer months. From March to August, the UV Index reaches its highest levels, particularly in May, June, and July, where it hits an extreme rating of 12. This signifies that the risk of harm from unprotected sun exposure is notably elevated, with a burn time as short as 10 minutes. March and April also present high-risk conditions with UV Index values of 9 and 10, requiring vigilance. Conversely, January, November, and December see a return to moderate levels, allowing for a more leisurely sun exposure of up to 30 minutes. Residents and visitors are advised to take extra precautions, especially during the high-risk months of March to August, by wearing sunscreen, protective clothing, and seeking shade during peak sun hours to minimize the risk of skin damage.

Monthly Maximum UV Index for Portola, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Portola. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.

Data source: Statistical UV Index data for Portola, based on information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

Compare Portola UV Index with Other United States Cities

The table above highlights how UV exposure in Portola compares to other major locations across United States. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.

Portola's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Chicago UVI	3	4	6	8	9	10	10	9	8	6	4	2
Brooklyn UVI	3	5	6	8	10	10	9	9	8	6	4	2
New York City UVI	3	5	6	8	10	10	9	9	8	6	4	2
Los Angeles UVI	4	6	8	9	10	11	11	10	10	7	5	4
Portola	4	6	9	10	12	12	12	11	10	7	5	3
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5