It really depends on how formal the wedding is. Even if it is more formal, there will surely be men there not in suits. It always happens like that. Besides, it's outdoors, which probably already means it's a little less formal. If the reception is indoors somewhere, I'd say leave the coat in the car for the wedding and wear it to the reception. I would tell my husband he doesn't need to wear a full suit to an outdoor June wedding. Also I do not think he should wear a brown tie with a black suit. I know you want to match, but at least you'll be up front in the wedding and he'll be seated, so it won't be noticable if you are matching or not.