Happy 4th of July!
Elka is not a dog bothered by fireworks (she'll lie to me about having to go out so she can try to see them. Protip: we can't see them from our house), but I get that a lot of dogs are. I'm surprised Elka isn't, really. This dog used to be afraid of plastic bags, and depending, they can still make her skittery. But she wants to watch thunderstorms and fireworks. Sure, Elka. It's just how she keeps us on our toes, with no way to tell what she'll love and what she'll hate sometimes.
Dogster ran an article this week about 6 tips to help your dog survive this Fourth of July. Obviously, my posting it today precludes you doing a "dress rehearsal", but you still have the time to get some extra exercising in, and to keep some of the human food onion and other dog toxin free to be utilized as high-value treats!
One of my coworkers uses a Thundershirt for storms; I don't know if they also use it for fireworks, but the Thundershirt works well for them and their dog. I "know" a couple of other people online who successfully use the Thundershirt for that type of anxiety. Amazon only has 10 left in stock of the one I linked, so either their word of mouth is fantastic, they work, or some combination of both. There is some evidence that they do have efficacy; I don't imagine the placebo effect much matters when you're talking about dog. This link doesn't have pictures, but does have the mechanics of using an Ace bandage to do essentially the same thing as a Thundershirt, and here is a Youtube demonstration
A good thing to remember is you can't reinforce fear in dogs (via Patricia McConnell), so please, if your dog is freaked by the fireworks, or by thunder, or by neighbors firing guns, comfort him or her. Redirect, give treats, train a behavior that can be safely utilized in a time like that so your dog has the tools to hopefully self-sooth. Patricia McConnell also tried out anxiety wraps (She's discussing thunderstorms specifically int his post) and didn't really see it "work", or it only partially worked, etc.