Summer Hair Care in the GTA: UV, Chlorine & Humidity

GTA summers give hair a completely different set of problems than winters. UV damage, pool chlorine, and lake humidity are working against you simultaneously. Each damages hair through a different mechanism, and a summer routine that addresses all three is different from your year-round approach.

Three Problems, One Season

GTA summers give hair a completely different set of problems than winters. UV damage, pool chlorine, and lake humidity are working against you simultaneously. Each damages hair through a different mechanism, and a summer routine that doesn't account for all three will manage some issues while letting others get worse. Our team sees the cumulative effect every September when colour-treated and bleached clients come in with brassy, dull, fragile hair that has been through a full GTA summer. Most of it is preventable with some adjustments made before the season starts.

What UV Does to Hair

UV radiation degrades the protein in the hair shaft. Specifically, it breaks down the amino acids in keratin that give hair its structure and strength. This is called photo-oxidation. It happens without you feeling it, and it accumulates across hours of sun exposure throughout the summer. For colour-treated hair, UV also oxidises the colour molecules, causing them to fade and go brassy faster. The lightest and most bleached sections are the most vulnerable, with less melanin to absorb UV and a more open cuticle to begin with. A UV-protective leave-in spray or SPF hair product applied before time outdoors is the most direct protection. They exist and they work. A wide-brimmed hat is also genuinely effective rather than just fashionable.

The Chlorine Problem

Chlorine strips the hair cuticle and oxidises colour molecules, causing greenish tints in very light or platinum hair and general dullness in all colour-treated hair. For bleached hair especially, chlorine penetrates the open cuticle and disrupts the keratin structure, contributing to the dry, straw-like feel that accumulates across a summer of pool visits. Here's the counterintuitive fix: rinse your hair with regular tap water before getting in the pool. Wet hair absorbs less chlorinated water than dry hair, because the hair shaft can only hold so much liquid, and if it's already saturated with plain water, chlorine absorption is significantly reduced. Apply a leave-in conditioner before rinsing and you add another layer of protection between your hair and the pool.

Humidity and Frizz in the GTA

Lake Ontario and the general humidity of GTA summers create the kind of ambient moisture that makes humidity-related frizz a consistent problem from June through September. Humid air doesn't damage hair the way UV and chlorine do, but it makes existing cuticle damage and porosity issues immediately visible. High-porosity hair (damaged, bleached, or chemically processed) absorbs humidity rapidly, swells unevenly, and frizzes. Low-porosity hair may resist it initially but still shows the effects on heavy-humidity days. Anti-humidity serums with silicones or glycerin work by creating a temporary barrier on the cuticle. They need to be applied to damp hair before it dries; applying them to dry hair after the fact has significantly less effect.

The Case for a Colour Gloss in Summer

A colour gloss or toner treatment mid-summer is one of the most effective and underused tools we offer. It refreshes colour vibrancy, adds shine, temporarily seals the cuticle to reduce frizz, and can be done between full colour appointments without the processing load of a full recolour. For clients who spend significant time outdoors or in pools, a gloss at the six-week mark of a colour appointment can extend the colour's lifespan by another four to six weeks. It takes 30 to 40 minutes, causes no damage, and makes a visible difference to how colour looks coming into the back half of summer.