Summer dictates lighter, brighter colors and lightweight fabrics but that shouldn't be the only consideration.
Is the wedding formal? Is it being held in a church or temple? Is it an outdoor venue? What time of day is the ceremony? Is there a reception immediately following the ceremony, or will it be held hours later?
The invitation speaks volumes about what might be the most appropriate dress. A formally printed or engraved invitation on white or cream vellum or parchment with standard wording such as,
Mr. and Mrs. Jones request the honor of your presence . . ."
dictates a more formal mode of dress.
Today, many couples are waiting longer to get married and are paying for the wedding themselves so they are in fact the hosts, rather than the brides parents which has been customary for many decades.
Dressing for an outdoor ceremony requires some thought. Where is the location? What will the weather be? A less formal mode of dress will probably be acceptable but the foremost consideration has to be comfort and appropriateness to the location. A black suit and high heel pumps will obviously look out of place at a beach wedding. A sundress would be a better choice but if the wedding is at sunset or later, you may be uncomfortably cool.
Formal ceremony held in a church or temple
A dress in your best basic or accent color, solid rather than printed, with understated jewelry and a simple pump. A dress with matching jacket could be the perfect choice. If the ceremony is after 4:00 pm, the jewelry can be more "glam."