Our family (two adults, two kids ages 3 and 6) wants to try a new beach location for a 2-week getaway in late July/early August.
We live in Arizona so the main goal is to escape the heat. Sweatshirts at nice would be just fine. We'd like to try something other than California, an Arizona favorite. Only other spot we've tried in summer is Cape Cod. A vacation home or resort is fine.
Any thoughts? Is Sanibel/Captiva in Florida out of the question due to humidity?
Thanks for any suggestions.

Yes, it would be too hot for your sweatshirt evenings. Those are more like tank top (at most) evenings.

I can't think of any place that suits you besides CA, but then again I've never been after that "cooler" beach experience.

The only other option I could think of is a high elevation lake somewhere that has beaches and a fun town to go along.

I would highly recommend hilton head island south carolina. I remember a few years back when i was there during the summer we needed sweatshirts at night. It is a very nice family place and although eating tends to be the expensive part, you can find very good prices on places to stay as long as you check the right places. Myrtle beach is a hop away and virgina as well. Both virgina and south carolina have great vacation rentals.

With all due respect to the previous poster, it was a very unusual night in Hilton Head if people were wearing sweatshirts in the high summer. The average low temp in this part of the world in July/August is about 70 degrees. With humidity to match.

Consider Maine or perhaps the Great Lakes.

What about the North West - Washington (with a possible drop down into Northern Cal) for Redwoods? Or Alaska - my sister went recently and said it was incredibly beautiful, mountains, ocean, etc. and not too hot!

I think you might like northern Michigan. Of course, that time of year, almost anywhere in north america can have a hot and humid night. I'm thinking Petoskey, Harbor Springs or Mackinac Island or Traverse City. The Sleeping Bear Dunes are beautiful, lots of clear lakes to swim in. Lovely.

Do you want to stay in one place for 2 weeks, or are you open to a little touring or day trips - depends on your family style. You might consider flying into Boston and instead of heading south to Cape Cod try North Shore Mass. beaches or Maine coast. Weather is not as predictable as you would like - could be 95 degrees and humid or sweatshirt weather at night.

Do you like beach or is ocean swimming essential - since most northeast ocean is way too cold for most people to swim in (although by August/September it gets its warmest). However, I can't think of too many places where you can wear a sweatshirt at night and water is warm enough for comfortable swimming.

Other possibility is Aruba.

Anything south of Virginia Beach, VA will be too warm and humid for sweatshirts.

Kelley's Island, Ohio or Mackinac Island, MI.

I second (or third) Lake Michigan! I was there (outside of the Petoskey/Traverse City area) in late August and it was downright cold at night (wool blanket weather) but the daytime was fine for boating or swimming. It was SO beautiful and peaceful. It's heavily wooded...so probably very different from what you're used to.

I think Virgina Beach is a great place, especially for families with young children. It is extremely clean and there are tons of things to do in the area.

How about Vail, Colorado. I just moved to Arizona from the Vail Valley and will definitely go back to escape the heat this summer. It's so beautiful during the summer but I'd go during July or August to be sure you're getting the best weather. You can make day trips to Aspen also - 1 1/2 hr drive. There's golf, rafting, horseback riding, hiking and more. I don't think you'll be disappointed.

I just re-read your message. I missed the part about a beach vacation. Vail. CO is obviously not near a beach but a great vacation anyway.

kendallg,
Here's a biased plug (I'm a LI'er) for Montauk, Long Island.

Southwest flies to Islip and it's ~1 hour drive to Montauk. Plenty of oceanside hotels and tons of kids - Montauk is the most "family friendly" town on LI's east end. Lots of web sites to check things out.