I’ve lived my whole life in the UK humidity puzzle: one minute the sun makes an appearance and my hair behaves like it’s auditioning for a frizz commercial, the next minute rain softens everything into a dull, puffy halo. Over the years I’ve tried dozens of products and techniques, and nothing’s been as reliable, affordable and versatile as a good drugstore hair oil. Below I share the best high-street finds I keep returning to, why they work in humid weather, and exactly how I use them — step by step — so your hair stays smooth without feeling greasy.
Why hair oil actually helps in humid summers
It might sound counterintuitive to put oil on hair when the air is already moist, but oils do a brilliant job at sealing the hair cuticle. When the cuticle is smooth and sealed, moisture from the air can’t swell the hair shaft as easily, which is what causes the frizz. A lightweight oil creates a barrier that keeps humidity at bay while also adding shine and softness.
For humid UK summers I look for oils that are:
Lightweight and non-greasyContain ingredients that penetrate (like argan, jojoba) or form a breathable shield (like dimethicone-free botanical blends)Either formulated for frizz control or marketed as smoothing/anti-humidityMy go-to drugstore hair oils
Below are the products I reach for most often. I’ve included what I love about each one and the hair types they suit best.
MOROCCANOIL Treatment Light — A cult favourite. The light formula is great for fine to medium hair. Gives instant shine and tames frizz without heaviness.OGX Renewing + Argan Oil of Morocco — Budget-friendly, widely available, and adds a lot of gloss. Works well on drier, thicker hair but use sparingly on finer textures.John Frieda Frizz Ease Extra Strength Serum — A classic for humid weather. Silicone-forward formula creates a strong anti-humidity barrier; perfect for curly or frizz-prone hair.TRESemmé Keratin Smooth Serum — Affordable, easy to find, and provides smoothness and manageability. Great for blow-dried hair and everyday de-frizzing.Garnier Fructis Sleek & Shine Anti-Frizz Serum — Lightweight and pleasant scented. Good for quick touch-ups and travel.Simple Nourishing Multi‑Oil — If you prefer minimal ingredient lists and something light for scalp and hair, this is gentle and multipurpose.Quick comparison table
| Product | Best for | Key benefit |
| MOROCCANOIL Treatment Light | Fine to medium hair | Lightweight shine, non-greasy |
| OGX Argan Oil | Thick/dry hair | Deep gloss and nourishment |
| John Frieda Frizz Ease | Very frizzy/curly hair | Strong anti-humidity barrier |
| TRESemmé Keratin Smooth | Blow-dried styles | Smoothing and heat protection boost |
| Garnier Sleek & Shine | All hair types | Lightweight, quick touch-ups |
How to apply oil so it actually tames frizz (and doesn’t weigh you down)
Applying hair oil might seem obvious, but small differences make a huge difference. Here’s my step-by-step routine that works whether I’m styling after a wash or smoothing morning flyaways.
Start with damp hair for best absorption. I towel-dry gently until hair is about 70–80% dry. Oils absorb better and distribute more evenly on damp hair than on bone-dry hair.Use the right amount. For short hair, a single drop; for shoulder length fine hair, 1–2 drops; for thick or very dry hair, 3–4 drops. Warm the oil between your palms first.Apply mid-lengths to ends first. These areas need the most smoothing and hydration. Avoid the roots unless you have very dry scalp or thick coarse hair that can handle it.Comb through with a wide-tooth comb. This ensures even distribution and detangles, preventing you from concentrating oil in one spot.Finish with a light smoothing stroke. After blow-drying or air-drying, I add one more tiny drop to the ends or to any persistent flyaways. A little goes a long way.Use as a finishing serum on styled hair. For blowouts or heat-styled looks I use a dab post-styling to add shine and control flyaways. If using silicone-heavy serums (like John Frieda), remember they’re excellent anti-humidity shields but can build up over time — clarify occasionally.When to apply oil: morning vs night vs pre-wash
There are three main times I use oil, and each gives different benefits:
Before styling (on damp hair) — Helps protect and smooth during blow-dry. I rely on this most summer mornings.After styling (as a finish) — Adds shine and weights down stubborn frizz. Great for quick touch-ups before heading out.Overnight or as a pre-wash treatment — For a deep conditioning boost, I’ll apply a little more oil to the lengths and sleep on it (put a towel on your pillow). Rinse out in the morning. This is my go-to when humidity plus city pollution has dulled my hair.Common mistakes to avoid
Using too much oil. This is the fastest route to limp, greasy hair. Start tiny and add more if needed.Applying to roots by default. Most people don’t need oil at the scalp — it’s the lengths and ends that benefit.Skipping a weekly clarifying wash. Oily or silicone-heavy products can build up. I use a clarifying shampoo or a vinegar rinse every 10–14 days to avoid residue.Ingredients to look for and avoid
In humid climates I prioritise lightweight plant oils and serums that form a protective but breathable layer:
Look for: Argan oil, jojoba oil, grapeseed oil, silicone-free serums with plant extracts, dimethicone if you want a strong humidity barrier.Avoid (if you’re oily-prone): Heavy mineral oils, overly rich butters (like pure shea), and using large amounts of silicone products without occasional clarifying.DIY quick mix for on-the-go smoothing
If you like mixing your own little travel serum, try this simple blend I keep in a tiny roller bottle:
6 drops argan oil (pure or from a light oil blend)3 drops jojoba oil1 drop lavender essential oil (optional, for scent)Roll between palms, then smooth sparingly over lengths. It’s lightweight, smells lovely, and keeps frizz down for a few hours.
Final practical tips I swear by
Carry a travel-size oil or serum for touch-ups — humidity can change fast in the UK.Pair oil use with a good humidity-resistant styling product if you’re expecting a stormy commute (serums + a light hairspray work wonders).Remember that consistency beats overloading: a small amount used well every day keeps your hair healthier than occasional heavy treatments.If you struggle with specific issues — very fine hair, thick curls or scalp sensitivity — tell me about your hair in the comments and I’ll suggest the best drugstore options tailored to your needs. I love helping readers find practical, realistic fixes that fit a busy life.
