It's August in America, so everywhere east of the Continental Divide will be some combination of hot, muggy, miserable, buggy, or swamped with tourists.

Anywhere west of the Continental Divide is going to be desert or coastal and wonderful. (Seattleite here, who gloats looking at the weather map of the USA with EVERY SINGLE STATE bright red, and a small green spot in the upper left corner.)

So I'd get over your dislike of heat/humidity, and just accept that it's August.

MY SUGGESTION:

Don't go anywhere in particular. Get in your car and head out in a direction you have never gone. Turn off the phone. Turn off the GPS. Follow the Sun. Or don't. Go towards that mountain over there. Or not. Avoid all freeways, and anything that is more than two lanes wide.

If something catches your eye, stop. Explore it. Take a photo of it. Climb on it. Eat there. Whatever.

Then drive some more. Find a motel. Stop and get a room for the night. Walk into a local bar and sit at the bar. Order a drink. Chat with the bartender or the person on the stool next to you. Go back to the motel and sleep, without setting an alarm.

Wash, rinse, repeat.

Here's why:

You have all your life to go See The Sights and Go To Museums and Eat At That Special Restaurant and blah blah blah.

What you WON'T have later in life, is FREE TIME TO DO WHATEVER THE FUCK YOU WANT. To explore freely and discover shit other people don't know about.

Here's a way to look at it: Your romantic partner is going to have places they want to go and see. And they will want to explore with you. New Orleans. Disneyland. The Fallingwater House. Whatever.

But how often will you get to take them on a romantic getaway to this little out-of-the-way place you found on a backroad in Virginia, where they have their own _______ and make their own ______ and you can do a _________ like nowhere else in the world? Share with them your experience? Take them on an adventure? (And do MORE exploring with them once you are there, so its not just you dragging them to a diner where you once had a great burger, but the two of you having a new experience together?)

Throw some clothes in the car. And a lot of music. And some water and PowerBars. And hit the road. See what happens.

You will ALWAYS remember that trip fondly. For the rest of your life. I guarantee it.