UV Index in Ottawa, United States

Last updated: May 3, 2025

In Ottawa, United States, being aware of the UV Index is crucial for residents and visitors alike, as it directly impacts your sun safety and skin health. Understanding UV levels is essential to prevent sunburn and long-term skin damage, which can lead to more serious health issues over time. Ottawa experiences a Cfa climate, characterized by hot summers and moderate UV exposure, particularly during the peak sunlight hours between 10:00 AM and 2:00 PM. With UV levels reaching as high as 10 at noon, staying informed is key to enjoying the sunshine while protecting your skin effectively.

Hourly UV Index in Ottawa

As the sun rises, the UV Index gradually climbs, beginning at a mild 1 at 7:00 AM. By 9:00 AM, it reaches 3, prompting early risers to consider sun protection. The intensity peaks at 1:00 PM with a maximum of 10, signaling the most hazardous conditions for unprotected skin. As the afternoon unfolds, the index dips from 9 at 2:00 PM to 6 by 4:00 PM, offering a brief respite. As the day winds down, the UV rays decrease, falling to 2 by 6:00 PM and returning to a safe 1 by 7:00 PM. Stay mindful of these fluctuations to enjoy the sun while safeguarding your skin!

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	3	moderate	30 min
10:00	5	moderate	30 min
11:00	7	high	25 min
12:00	9	very high	15 min
13:00	10	very high	15 min
14:00	9	very high	15 min
15:00	8	very high	15 min
16:00	6	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 Ottawa

Throughout the year, seasonal UV changes present varying risks for sun exposure. The high-risk months typically occur from April to August, when the UV Index rises to 9 or above, indicating very high to extreme exposure levels. Specifically, June and July see the most critical levels at 11, suggesting a burn time of just 10 minutes. Visitors and residents should be particularly vigilant during these months, applying sunscreen with a high SPF, wearing protective clothing, and seeking shade during peak sun hours. As the UV Index decreases from September to December, with values dropping back to 3-6, precautions remain advisable but can be somewhat relaxed, particularly in the winter months.

Monthly Maximum UV Index for Ottawa, United States

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

The table above highlights how UV exposure in Ottawa 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.

Ottawa'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
Ottawa	3	6	7	9	10	11	11	10	9	7	4	3
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