UV Index in Grafton, United States

Last updated: May 3, 2025

Understanding the UV Index in Grafton, United States, is essential for safeguarding your health under the sun. With peak UV levels reaching up to 9 during midday hours, it is crucial to grasp the significance of these measurements for sunburn prevention and overall skin health. Grafton, known for its humid continental climate, presents unique challenges for UV exposure, particularly in the summer months when the sun is at its strongest. By staying informed about the UV Index, residents can take proactive measures to enjoy the outdoors safely while minimizing the risks associated with harmful UV radiation.

Hourly UV Index in Grafton

As the sun rises, the UV Index gradually climbs, starting at a mild 1 at 07:00. By 08:00, it nudges up to 2, signaling a gentle start to the day. The real intensity kicks in at 09:00, reaching 4, and peaks impressively at 12:00 with a high of 9. The UV levels remain strong throughout the afternoon, holding at 9 until 13:00, before tapering off slightly to 8 at 14:00. By 15:00, it decreases to 7, and as the sun begins its descent, the index drops dramatically, hitting 4 by 16:00 and further declining to a safe 1 by 18:00 and 19:00. Staying sun-safe during the peak hours between 10:00 and 14:00 is essential to protect your skin from harmful UV rays!

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	6	high	25 min
11:00	8	very high	15 min
12:00	9	very high	15 min
13:00	9	very high	15 min
14:00	8	very high	15 min
15:00	7	high	25 min
16:00	4	moderate	30 min
17:00	3	moderate	30 min
18:00	1	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Grafton

Throughout the year, UV exposure varies significantly, with high-risk months typically from April to August, where the UV Index peaks at levels of 8 to 10, resulting in a very high exposure category and a quick burn time of just 15 minutes. In contrast, the winter months of January, February, and December feature a much lower UV Index, ranging from 2 to 4, which is classified as low to moderate, allowing for longer exposure times of 30 to 45 minutes without significant risk. To protect against harmful UV rays, it’s crucial for visitors and residents alike to use sunscreen, wear protective clothing, and seek shade during the peak sun hours, especially from April to August when sun safety practices should be a top priority.

Monthly Maximum UV Index for Grafton, United States

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

The table above highlights how UV exposure in Grafton 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.

Grafton'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
Grafton	3	4	5	8	9	10	9	9	7	5	3	2
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
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5