When do you suggest we visit? When is high season? Shoulder season?We can visit anytime except winter. How about best time for region's beaches. Hotel rates and weather are important factors.
Your input is very appreciated. Thanks.

Where are you coming from and what do you want to do?

Summers in these cities are hot and humid, really subtropical.

May is a great month, as is September and early October unless there is a hurricane.

Both cities have nearby beach communities of various types, and they are linked by US 17 through Beaufort, a place worth visiting on its own.

Right. Where are you coming from? If you live in the cold you might like March. The azaleas bloom in April. May is great, but it's busy with the Spoleto Festival. The ocean is still chilly (for me anyway) in spring.

October is my favorite month here.

Read through some of the trips reports here to get an idea of what others have enjoyed.

Beach rates will be high summer and early fall IF you are planning on renting there. Hotel rates rise with "events" like the various marathons they have--or events at College of Charleston and The Citadel. Sue, feel free to correct me on this.
But truthfully, Charleston and Savannah probably are "in season" most of the year because of their appeal and the mild weather. Great places to visit, eat well, and enjoy.
The azalea season is wonderful--don't forget the plantations also.
And October in the southeast coast is absolutely beautiful, as Sue points out.

Gretchen, you are right. Spring is VERY popular. It's beautiful when all the gardens start blooming. Prices reflect that. And there are lots of events that make rates spike. Staying in the Historic District is never cheap, but the convenience makes it worth it, especially for first timers.

Thanks for your help. We want to do the historical bldgs, museums,the squares,etc.,restaurants and little shops.Just want a feel of these cities and the low country. I live in Colorado and my sister from Iowa.

If gardens aren't on the top of your list then think about coming in October. The humidity will be gone, the weather is usually great, and the ocean will still be warm.