UV Index in Louisville, United States

Last updated: May 3, 2025

Understanding the UV Index is crucial for residents of Louisville, United States, where sun exposure can be intense, especially during the warmer months. With UV levels frequently peaking around 11, becoming aware of UV risks not only helps prevent painful sunburns but also plays a vital role in maintaining overall skin health. Louisville's Cfa climate features humid summers that can elevate UV exposure risks, making it essential for locals to stay informed and protect themselves during peak sun hours, particularly around noon.

Hourly UV Index in Louisville

The UV Index throughout the day paints a vivid picture of sun intensity and its impact on outdoor activities. Starting early at 7:00 AM, the exposure remains low at a mere 1, ideal for morning strolls. As the sun climbs, 9:00 AM sees a slight increase to 3, hinting at the day's potential. By 10:00 AM, the index escalates to 5, and it reaches a peak at 12:00 PM with a blistering 10. The highest point occurs around 1:00 PM and 2:00 PM, where it hits 11, indicating the need for sun protection. Gradually, the index begins to decline, drifting down to 7 by 4:00 PM, and dropping to a safe 1 by 7:00 PM, closing the day with a protective embrace as twilight falls. This information serves as a crucial guide for planning sun-safe activities!

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	7	high	25 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 Louisville

Throughout the year, the UV Index experiences notable fluctuations, with the highest values occurring from March to August. Specifically, May through July are characterized by an extreme UV Index of 11, necessitating caution as the burn time is reduced to just 10 minutes. These peak months represent a high-risk period for sunburn and potential skin damage. In contrast, January and December see the lowest UV exposure, categorized as moderate with burn times of up to 30 minutes. Visitors and residents are strongly advised to take protective measures, such as wearing sunscreen and protective clothing, particularly during the high-risk months of March to August. Staying informed about the UV Index can help ensure a safer experience outdoors.

Monthly Maximum UV Index for Louisville, United States

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

The table above highlights how UV exposure in Louisville 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.

Louisville'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
Louisville	4	6	8	10	11	11	11	10	9	7	6	3
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5