UV Index in St. John's, Canada

Last updated: June 2, 2025

Understanding the UV Index is crucial for residents and visitors in St. John's, Canada, where varying levels of ultraviolet radiation can significantly impact skin health and sunburn risk. With a climate characterized by its Dfb classification, St. John's experiences its highest UV levels in the summer months, reaching a peak of 10 around midday. This highlights the importance of being aware of UV exposure, especially during peak hours, to protect against harmful effects and ensure safe outdoor activities. By staying informed about the UV Index, you can enjoy the stunning natural beauty of St. John's while safeguarding your skin's health.

Hourly UV Index in St. John's

The UV Index shows a clear climb in intensity throughout the morning, starting at a manageable 2 at 07:00. By 09:00, it jumps to 5, signaling the onset of stronger sun exposure. The peak arrives at 12:00, with a sky-high 10, urging sun lovers and outdoor enthusiasts to take necessary precautions. As the afternoon unfolds, the index gradually dips from 9 at 13:00 to 5 at 16:00, providing some relief. As the sun sets, the numbers dwindle to a 3 at 17:00 and settle at 1 by 18:00 and 19:00, marking a retreat from the day's strongest UV rays. Remember, while fun in the sun is tempting, staying protected during peak hours is essential!

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	2	low	45 min
08:00	3	moderate	30 min
09:00	5	moderate	30 min
10:00	7	high	25 min
11:00	9	very high	15 min
12:00	10	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	5	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 St. John's

Throughout the year, UV exposure significantly fluctuates, with high-risk months typically occurring from April to August. During this period, the UV Index peaks at 10 in June, indicating extremely high exposure levels and a burn time as short as 15 minutes. Visitors and residents should exercise caution during these months, particularly in May, June, and July, when UV readings are in the very high category. To protect against skin damage, it's advisable to seek shade, wear protective clothing, and apply sunscreen regularly. The UV Index decreases in late summer and fall, dropping to moderate levels in October and returning to low in the colder months, from January to March and again in November and December, allowing for more prolonged outdoor activities with reduced risk.

Monthly Maximum UV Index for St. John's, Canada

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in St. John's. 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. John's, 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. John's UV Index with Other Canada Cities

The table above highlights how UV exposure in St. John's compares to other major locations across Canada. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.

St. John's's solar exposure compared to other cities in Canada. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Edmonton UVI	2	3	5	6	7	7	8	7	6	4	2	1
Calgary UVI	2	3	4	6	8	8	9	8	7	4	2	1
St. John's	2	3	5	7	8	10	9	8	7	4	2	1
Montreal UVI	2	4	5	7	9	9	8	8	7	5	3	2
Ottawa UVI	2	4	5	8	9	9	8	8	7	5	3	2
Toronto UVI	2	4	5	8	9	9	9	9	7	5	3	2