The cropped top is a pretty choice for hot weather. Wear it solo or layered under a jacket and balance the cropped silhouette with high-waisted styles - a midi skirt or wide-leg pants.
If you're not planning on spending much, this Material Girl Cropped Top will fit the bill. It's a fail-safe choice, while not very expensive. Another strong contender for your wardrobe is this Free People Cropped Top. While the price of this piece is not very high, it will definitely attract a lot of attention. You might also want to consider this Made Cropped Top. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.