Hot Weather Activewear: What to Wear When It's 90°
- Words by
- Julio Arco
- Published
- Reading
- 4 min
When it's 90 degrees, wear a light, breathable top, a short stretchy bottom and a fabric that moves sweat off your skin instead of holding it. Synthetic knits made for wicking, or linen-type weaves for casual days, beat heavy cotton almost every time.
Stretchy bike shorts fit this brief well. They don't bunch, they don't chafe the way loose seams can, and they look right with a sporty-casual outfit. Here is how to choose the fabric, the fit and the pairings.
What fabric is best for hot weather workouts?
Look for moisture-wicking workout clothes for heat: polyester or nylon blends with some spandex, usually in a light, open knit. They pull sweat to the surface of the fabric so it can evaporate, which is what actually cools you.
Cotton is the one to be careful with. Georgia Tech's News Center notes that cotton's moisture vapor transmission rate is lower than linen's, meaning it doesn't dry as quickly. A damp cotton tee clings and stays heavy, which is fine for a walk to the cafe and not so fine for a run.
For the shorts themselves, check that the label lists some elastane or spandex for four-way stretch, and that the fabric feels smooth and light in your hand. Thick, compressive, very shiny fabric tends to feel hotter against skin.
Loose fit or close fit when it's hot?
Both work, for different reasons. A loose top lets air move around your torso, so it suits breathable shirts for hot weather. A close-fitting bottom keeps fabric from sticking and rubbing in motion, which is why bike shorts are comfortable for long days on your feet.
Through the lens of evidence-based design, I'd balance the two: one loose piece, one close piece. It also reads better to the eye, because the proportions look intentional instead of baggy or tight everywhere.
What are the best gym clothes for people who overheat?
- A lightweight tank or short-sleeve tee in an open, wicking knit, or one with mesh panels at the back.
- Bike shorts or shorts with a short inseam, in a light, smooth fabric with a flat waistband.
- Light colors if you're outdoors. Dark colors look more forgiving with sweat, but they absorb more heat in direct sun.
- Seamless or flat-seam construction, which reduces rubbing where skin stays damp.
If you overheat or sweat heavily and it worries you, check with your doctor. Clothing helps comfort, but it can't answer a health question.
For a longer-legged cut that stays light, the stretchy capri leggings for mild summer days are a good next step when 90 degrees isn't on the forecast.
How to style bike shorts for sporty casual looks
Oversized tee and sneakers
An oversized cotton or linen-blend tee, bike shorts and white sneakers is the easy formula. Keep the tee short enough to show the shorts' hem, or tuck the front corner in to keep the proportions clear. There's more in the same spirit in comfy bike shorts for athleisure days.
Tank and lightweight blazer
A fitted tank under an unlined blazer dresses the shorts up for lunch or a casual meeting. Choose sleek sneakers or flat mules, and a black or neutral short so the blazer leads.
Loose shirt and sandals
A loose button-up, tied at the waist or worn open, over a tank and shorts is the coolest version of this look. Add flat sandals and a straw hat if you'll be out in the sun.
Which color and pattern should you pick?
Black is the easiest: it goes with every top and hides sweat marks best. Beige, gray and taupe give a softer, muted look that sits well with casual neutral tones.
Bright colors such as cobalt or coral make the shorts the focus, so keep the top plain. The same goes for prints: camo or animal print works best with a solid top and quiet accessories.
As an architect trained in evidence-based design, I'd also look at surface. A matte knit and a glossy one in the same color read differently, because the finish changes how light reaches your eye, and matte tends to look more casual.
Protect your skin in the sun
Shorts leave legs exposed, so if you're exercising outdoors, sun protection matters. The Skin Cancer Foundation says a UPF of 30 to 49 offers very good protection, while UPF 50+ offers excellent protection. Sunscreen on exposed skin is still worth discussing with your dermatologist.
For your head, Anna L. Chien, MD, of Johns Hopkins University School of Medicine, says: "A hat with a 3-inch brim protects the top of your scalp, ears and face." A brimmed hat or one of these visors is a good partner for the outfit.
What to wear in extreme heat
Go lighter and looser than you think: a wicking or loosely woven top with short sleeves or a UPF-rated long sleeve, short bottoms and a hat. Skip layers, and plan fewer, shorter sessions outdoors. If you feel dizzy or unwell, stop and get somewhere cool.
Frequently asked questions
What is the coolest clothing to wear in hot weather?
Light, loosely woven or open-knit fabrics in light colors are the coolest. Linen and wicking synthetics both work, while heavy cotton stays damp longer.
What is the best clothing to wear in extreme heat?
Wear loose, lightweight pieces that let sweat evaporate, plus a brimmed hat. If you're outdoors for long, a UPF-rated top adds sun protection.
Are bike shorts too hot for summer?
Not if the fabric is light, smooth and has good stretch. Thick, compressive pairs can feel warmer, so pick a thinner knit for 90-degree days.
Filed under Wardrobe Basics
