Live UV forecast for 510 cities
Canada stretches from 42.0501° to 62.4541° latitude (Northern hemisphere), so UV conditions differ a lot from region to region. The clear-sky UV index reaches ≈ 7.9 in Chatham (peak in June), while in Yellowknife the yearly maximum is only ≈ 6.
| Zone | Cities | J | F | M | A | M | J | J | A | S | O | N | D | Peak |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temperate | 505 | 2.3 | 3.4 | 4.8 | 6.3 | 7.1 | 7.6 | 7.4 | 6.7 | 5.7 | 4.3 | 3.1 | 2.2 | 7.6 |
| High-latitude | 5 | 0.9 | 1.8 | 3.2 | 4.8 | 5.9 | 6.5 | 6.3 | 5.4 | 4.2 | 2.7 | 1.5 | 0.8 | 6.5 |
Calculated clear-sky noon peaks at the average latitude of each zone. Real values vary with clouds, altitude and ozone.
Using Toronto as a reference: the UV index reaches 6+ in April, May, June, July, August and September. In the sunniest zones (see table) SPF 30–50+ is needed almost year-round; in the mildest — only in late spring and summer.
The calculated clear-sky maximum is ≈ 7.9 — in Chatham around June. Values above this occur only near the equator and in high mountains.
Chatham (peak ≈ 7.9), followed by Kingsville and LaSalle. The mildest sun is in Yellowknife (max ≈ 6).
In Toronto and similar latitudes the UV reaches 6+ in April, May, June, July, August and September: use SPF 30–50+ on sunny days. Protection is advised from UV 3.
No — the local maximum is ≈ 7.9. UV 11+ occurs only near the equator, in deserts and high mountains.