12 beautiful, heatwave-ready dresses from Zara, H&M, and COS

We’re officially in the middle of a heat wave, and all I want to do is wear a breezy dress. Now that the sun is here, I’m returning to one of the most reliable summer blueprints — dress, sandals, basket bag. After locating the best basket bags around and wading through the influx of new sandals to find the cutest styles, now’s the time to turn our attention to sleek apparel. After hours of searching, I found the best summer dresses at Zara, H&M, and COS.

wears flori COS Embroidered Pima Cotton Midi Dress (£119)

(Image credit: @floriealexander)

This trifecta of high street brands is known for expensive-looking dresses. With its focus on enduring colors, elegant silhouettes and sophisticated design details, this selection of summer dresses can easily be had for three times the price. It can take hours of searching through the must-have sections to find these extraordinary styles, but I’ve taken one for the team, and have prepared an edit of the best below to give you more time in the sun.

Whether you’re more minimalist or are into bringing up the drama with boho embellishments, this edit has something for you. For summer 2026, COS lean towards sophisticated silhouettes with low-back designs to ensure they retain their contemporary feel year after year. At Zara, playful updates come in the form of polka-dot prints, pointelle knitwork and intricate embroideries that add a romantic mood to summer dressing. Finally, H&M is bringing sophistication by focusing on silhouette. Check out the smocked bodice, draped fabric and sophisticated halterneck that make these high-street dresses incredibly sophisticated. Now, I’ve rounded up the hottest summer dresses at Zara, H&M and COS for summer 2026.