UV Index in St. Marys, United States

Last updated: June 2, 2025

Understanding the UV Index is crucial for residents of St. Marys, United States, especially given the area's Cfa climate, characterized by warm summers and mild winters. With peak UV levels soaring to 11 around midday, it’s vital to be aware of the potential risks associated with UV exposure, such as sunburn and long-term skin damage. By monitoring the UV Index, you can take proactive steps to protect your skin and enjoy sun-filled days safely. As the sun reaches its highest intensity during the summer months, staying informed about UV levels will help you and your family stay healthy and sun-smart.

Hourly UV Index in St. Marys

The UV Index for the day showcases a dramatic increase in intensity as the sun climbs higher in the sky. Starting at a mild 1 at 07:00, it remains low throughout the morning, only reaching 3 by 09:00. However, by 11:00, the index skyrockets to 8, peaking at an intense 11 from 13:00 to 14:00. As the afternoon wanes, the UV levels gradually decrease, dropping to 4 by 17:00 and tapering off to 1 once again by 19:00. It's clear that midday hours pose the greatest risk for sun exposure, making it crucial to take precautions during the peak hours from 11:00 to 14:00.

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	10	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