Live forecast
The UV index measures the intensity of ultraviolet radiation reaching the ground. Even on overcast days, UV rays penetrate cloud cover and affect your skin — making daily sun protection essential year-round in Ottawa.
Live forecast from Environment Canada. See also our weather & skin health dashboard and Ottawahenge alignment guide.
Low
Today's peak UV index for Ottawa
7:15 AM · 6:23 PM
Tuesday
Typical peak UV by month (45.4°N)
Representative daytime peak UV values based on Ottawa's latitude. Source: WHO Global Solar UV Index Programme, Health Canada. Actual daily values vary with weather, cloud cover, and ozone levels.
| UV Index | Category | Risk | What to do |
|---|---|---|---|
| 0 – 2 | Low | Minimal danger for the average person | Wear sunscreen if you have sensitive skin or have had recent cosmetic treatments. SPF 30+ recommended. |
| 3 – 5 | Moderate | Moderate risk of harm from unprotected sun | Apply SPF 30+ sunscreen. Seek shade during midday hours. Post-treatment skin: SPF 50+ mandatory, reapply every 2 hours. |
| 6 – 7 | High | High risk of harm — protection is essential | SPF 50+ required. Wear a hat and sunglasses. Avoid direct sun 11 AM – 3 PM. After laser or chemical peel: stay indoors during peak hours if possible. |
| 8 – 10 | Very High | Very high risk — unprotected skin burns quickly | Minimize sun exposure. SPF 50+ with reapplication every 90 minutes. Post-treatment clients should avoid outdoor activities during peak UV hours entirely. |
| 11+ | Extreme | Extreme risk — take all precautions | Avoid the sun between 10 AM and 4 PM. Full protection required: SPF 50+, protective clothing, shade. Reschedule outdoor activities if recently treated. |
UVA rays (320–400 nm) penetrate deep into the dermis, breaking down collagen and causing photoaging, wrinkles, and hyperpigmentation. UVB rays (280–320 nm) affect the epidermis and are the primary cause of sunburn and DNA damage. Both contribute to skin cancer risk. Broad-spectrum sunscreen protects against both.
After laser hair removal, chemical peels, microneedling, or any treatment that disrupts the skin barrier, UV exposure can cause hyperpigmentation, scarring, or compromised results. Most providers recommend strict sun avoidance for 2–4 weeks post-treatment and daily SPF 50+ for at least 6 weeks. When in doubt, ask your provider.
Ottawa's UV index drops to 1–2 in winter, but UV rays still reach the ground — and snow reflects up to 80% of UV radiation. The March–April period catches many people off guard: UV rises quickly to moderate levels (4–5) before summer behaviour kicks in. Daily SPF is not seasonal — it's a year-round commitment.
Whether the UV index is Low or Very High, daily broad-spectrum sun protection is non-negotiable — especially around cosmetic treatments.
Full weather dashboard — pressure, humidity, air quality, UV, and how they affect your skin and treatments.
When the setting sun aligns with Ottawa's downtown street grid — best times for golden-hour walks and photography.
