UV Index in St. Marys, United States

Last updated: July 2, 2025

Understanding the UV Index is essential for residents of St. Marys, United States, where the climate offers warm summers and ample sunshine, but also presents unique risks for skin health. The UV levels in St. Marys can peak significantly, reaching a maximum value of 11 around noon when skin damage risks are elevated. Being aware of these levels helps residents take proactive measures against sunburn and long-term skin damage, ensuring a safer and healthier outdoor experience. Stay informed about daily UV forecasts to enjoy all that St. Marys has to offer while protecting your skin!

Hourly UV Index in St. Marys

The UV Index for the day showcases a striking pattern, starting moderate at 7:00 AM with a value of 1. As the sun climbs higher, the index steadily rises, hitting 3 by 9:00 AM, and then surging to a peak of 11 between 1:00 PM and 2:00 PM. This indicates a high risk of harm from unprotected sun exposure during midday. Following the peak, the UV Index gradually declines to 4 by 5:00 PM and further decreases to 1 by 7:00 PM, emphasizing the critical importance of sun protection during the intense midday hours. It’s advisable to seek shade and wear sunscreen if you're outside during the peak period!

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	1	low	45 min
09:00	3	moderate	30 min
10:00	5	moderate	30 min
11:00	8	very high	15 min
12:00	10	very high	15 min
13:00	11	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 St. Marys

The UV Index exhibits significant seasonal changes, peaking from May to August when it reaches an extreme level of 11, indicating a very high risk of harm from unprotected sun exposure with a burn time of just 10 minutes. The months of March through October are particularly high-risk, with March and April categorized as very high and May to August as extreme. Visitors and residents are advised to take precautions during these months by wearing broad-spectrum sunscreen, protective clothing, and seeking shade, especially during midday hours. Conversely, the risk diminishes in the winter months, with January and December recording a moderate UV Index of 5 and 4, respectively, allowing for more extended exposure times of 30 minutes without significant risk.

Monthly Maximum UV Index for St. Marys, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in St. Marys. 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 St. Marys, 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 St. Marys UV Index with Other United States Cities

The table above highlights how UV exposure in St. Marys 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.

St. Marys'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
St. Marys	5	7	9	10	11	11	11	11	10	8	6	4
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5