UPF labels tell you how much UV a fabric blocks. Here is what the numbers mean and how to build outfits that cover you without overheating.
Quick take
- Skin cancer is the most common of all cancer types in Canada, and about one third of all new cancer cases are skin cancers.
- UPF measures a fabric’s ability to block UV rays from reaching your skin; look for UPF 15 or higher, and UPF 50+ blocks most UV rays.
- Cover up when the UV Index is 3 or higher with light-coloured, long-sleeved shirts, pants and a wide-brimmed hat in breathable fabric.
- Thick, tightly woven fabric in dark colours provides the most effective protection against UV rays.
- Sunscreen labelled broad spectrum and water resistant with SPF of at least 30, reapplied every 2 hours, still matters on exposed skin.
Sunscreen gets all the attention, but clothing is the sun protection you never have to reapply. Health Canada advises covering up whenever the UV Index reaches 3 or higher, and the reasons are serious: skin cancer is the most common of all cancer types in Canada, and about one third of all new cancer cases are skin cancers. Here is what UPF ratings mean and how to put together outfits that cover you without overheating.
Why clothing is your first line of sun defence
UV radiation is the main cause of skin cancer, which is also one of the most preventable. A shirt covers a wide stretch of skin for hours without any effort on your part, which is why Health Canada’s basic advice starts with covering up: light-coloured, long-sleeved shirts, pants, and a wide-brimmed hat made from breathable fabric.
Sunscreen still has a job on every inch a garment leaves bare. Use one labelled “broad spectrum” and “water resistant” with an SPF of at least 30, apply it at least 15 minutes before heading out, and reapply at least every 2 hours. An adult needs about 7 teaspoons (35 mL) to cover all exposed skin, which is a lot of lotion. Clothing does the heavy lifting so the sunscreen is only filling in the gaps.
The other reason coverage counts is that UV finds you in sneaky ways. UV rays can get through clouds, fog and haze, and water, sand, concrete and especially snow reflect them back at you. A cloudy day at the beach is not a day off from sun protection.
What UPF means on a label
UPF stands for ultraviolet protection factor. It measures a fabric’s ability to block UV rays from passing through and reaching your skin, and fabrics are classified into categories based on their UPF. Like an SPF number, the higher the UPF, the less UV radiation reaches the skin and the better the protection. Look for UPF 15 or higher; UPF 50+ blocks most UV rays.
The difference between the two numbers comes down to what they apply to:
| SPF (sunscreen) | UPF (fabric) | |
|---|---|---|
| Applies to | Lotion or spray you apply yourself | The fabric itself |
| Recommended minimum | SPF of at least 30 | UPF 15 or higher |
| Best protection | Higher numbers filter more UV | UPF 50+ blocks most UV rays |
| Ongoing effort | Reapply at least every 2 hours | None while the garment covers you |
A sunscreen’s strength depends on using the recommended amount and reapplying often. A fabric’s protection holds steady as long as the garment covers your skin and stays intact.
What makes a fabric sun-safe
The same qualities that make awning fabric effective work for clothing. Thick, tightly woven material in dark colours provides the most effective protection, because less UV passes through the threads and the gaps between them. A quick check in the change room: hold the fabric up to a light source. The less light that comes through, the tighter the weave.
Coverage matters as much as the fabric itself. A long-sleeved linen shirt over a tank top protects more skin than a short-sleeve tee in the same fabric. Look at shoulders, upper backs and thighs, where the sun hits hardest and where fabric tends to sit close to skin.
Fabrics made for sun protection are often lightweight, and some are treated with ingredients that help them block UV rays. If a knit stretches thin over a curve or turns sheer when damp, it may cover less than the label number suggests, so check how the garment sits on your body, not just on the hanger.
Everyday outfits that cover you without overheating
Covering up does not have to mean heavy clothes. Health Canada recommends light-coloured, loose pieces in breathable fabric, which is exactly what our guide to what to wear in hot, humid weather is built around.
- Weekend: a loose, light-coloured linen shirt over a tank, wide-leg trousers or a midi skirt, and a wide-brimmed hat.
- Water days: a long-sleeved rash guard or UV-protective swim top, which stays put in the water while sunscreen washes off.
- Gardening or hiking: a lightweight long-sleeve shirt, long pants, a breathable sun hat and sunglasses with UVA and UVB protection.
- ** errands and patios:** a long-sleeve cotton or linen shirt you can slip on whenever you sit in the sun, even over a summer dress.
Timing helps too. In Canada, the UV Index can be 3 or more from 11 a.m. to 3 p.m. between April and September, even on cloudy days. Plan shade or indoor time around midday, and remember that when your shadow is shorter than you, the sun is very strong.
Style tip
Keep a light long-sleeve shirt in your bag or car in summer. Putting it on when you stop for lunch outdoors takes seconds and covers more skin than any amount of sunscreen.
How wear, washing and water change protection over time
A UPF rating describes fabric in good condition. Thin spots from wear, stretching at elbows and shoulders, and general ageing can all affect how well a garment covers you, so follow the care instructions on the label. Our guide to reading clothing labels in Canada explains the care symbols you will see. If a shirt has gone thin enough to see light through the fabric, treat it as a comfortable old favourite rather than sun protection.
With sunscreen, water and sweat are the bigger concern: even products labelled “water resistant” need reapplying after you get out of the water or sweat heavily. Clothing has the advantage here, which is why a rash guard earns its keep at the lake.
Pieces like breathable long-sleeve shirts, wide-brimmed hats and versatile trousers earn their spot in a wardrobe that works with everything, because they carry you from beach days to cool evenings all summer long.
Your style questions
Q: Does a regular t-shirt protect you from the sun?
A: It depends on the fabric. Tightly woven material in dark colours blocks more UV than thin, loosely woven fabric, and fabric stretched thin over shoulders or curves may protect less than you expect. A label showing UPF 15 or higher means the fabric has been rated to block UV.
Q: Do I still need sunscreen if I wear UPF clothing?
A: Yes, on any skin your clothing does not cover. Use a broad-spectrum, water-resistant sunscreen with an SPF of at least 30, applied at least 15 minutes before going out and reapplied at least every 2 hours.
Q: When should I worry about sun protection in Canada?
A: Protect your skin when the UV Index is 3 or higher. In Canada, the index can be 3 or more from 11 a.m. to 3 p.m. between April and September, even when it is cloudy.
Q: What should I look for in a sun hat?
A: A wide-brimmed hat made from breathable fabric. It shades your face, ears and neck, which are areas Health Canada specifically lists as easy to miss with sunscreen.
