Formal dresses to wear to a wedding include both evening gowns and elegant cocktail frocks, so pick the hemline you feel best in. Also, its totally fine to wear a suit. Accessorize with heels or fancy flats and jewelry as you see fit.
Either you wear a floor-length evening gown or a suit and nice loafers - you would be acceptable. Similarly, a midi or knee-length cocktail dress would also be appropriate instead of a floor-length gown.
The dresscode cocktail to an wedding is slightly less formal. Therefore - black-tie, tuxes and floor-length gowns are not required. A short formal dress or an elegant suit is a perfect choice to add with a pair of high heels and colorful jewelry.
A casual wedding dress code also comes with more flexibility in terms of experimenting with trendy colors, patterns and fabrics. So, if you're feeling up for it, you can opt for a wedding guest outfit that you wouldn't normally wear.
For this outdoor weddings, consider your shoe choice a attire for warmer climates. Shorter skirts and light, airy fabrics like linen and cotton will help you stay cool while keeping in line with the preferred wedding dress code.