If your wedding will be held in the spring or summer (in the more northern states), you most likely will be looking for spring wedding dresses as well as bridesmaids dresses. Your mother will also most like be looking for spring mother of the bride dresses.  Most of your female guests will be wearing spring dresses as well.  Whether your wedding is a formal church wedding or a beautiful informal outdoor wedding will dictate what type of spring dresses you, your bridal party and your guests will be shopping for.  

If your wedding will be an informal outdoor wedding,  you might want to choose a short dress.  If you have your heart set on a long gown, then look for informal wedding dresses that are made from lightweight, airy fabrics like chiffon.  You will also want to look at gowns that bare a bit more skin such as a halter top or strapless style.  Sundresses are also a popular choice for a spring wedding.  There are many beautiful sundresses that would be perfect for an informal outdoor wedding. Now if you are holding your spring wedding indoors, either in a church or some other venue, you could go with a long, more formal gown.  Still keep in mind that you may be outdoors taking photographs and you also have to get from one point to another. Therefore, if it is very warm in your area during the spring, you may want to still opt for the more lightweight fabrics but just choose a more formal style.  

Your bridesmaids will look spectacular in either sundresses, cocktail dresses or long evening gowns for the more formal wedding.  However, when choosing the bridesmaids dresses, keep in mind the fabric choices and the colors.  Most brides will choose to use pastel colors if they are having a spring wedding.  You might also choose to use a floral print for the bridesmaids dresses.  This is especially nice if you are having an outdoor wedding.  

One thing to keep in mind when you are shopping for spring dresses is that the weather can change at any moment.  Spring is usually pleasantly warm no matter what part of the country you are in.  However, it is not unheard of to have a cold spell even toward the end of spring, especially if you live in the northern part of the country.  Keep this in mind when shopping for your dresses.  While you don't necessarily want to purchase dresses that are made from heavier fabric or that have sleeves, you might want to consider also having a jacket or wrap that matches.  This way, if the day turns cold you and your bridal party can still keep warm.