I'm planning a trip flying into JAX, renting a car and visiting St Augustine for a couple of days. Then on to Savannah, Beaufort, Hilton Head and Charleston. I'm thinking 2 weeks but now I'm wondering if that's too long. Any advice is appreciated. Also, I was planning on Oct but now I'm wondering if spring would be a better time for the trip. Thanks in advance!

Either time would be lovely. In the spring you'd have the azaleas.
There is better beach than Hilton Head on the southeast coast.

Spring is beautiful; went to Charleston in May last year and it was pleasantly warm, sunny, flowers in bloom. I spent three nights in Charleston and could have easily taken a full week for the city, islands, and surrounding areas. Two weeks sounds excellent.

I'm sure fall is also nice, but October is part of hurricane season, and although not typically part of that Aug-Sept peak, strong storms do occur so you may want to think about trip insurance during that time. I think northern FL and the GA/SC coasts dodged Hurricane Sandy in October 2012 (and GA/SC in general have been spared worst storms in the last decade or so), but insurance might not be a bad idea if you do go in fall.

I've been to Savannah, Hilton Head and daytrip to Beaufort in early October and the weather was beautiful.

In the fall, you don't have to worry about dodging St. Patrick's Day, Easter, the Azalea Festival, Heritage Golf Weekend or spring break. I'd rather take my chances with a hurricane that these.

If you come in the spring, time it during garden week in Savannah.

Thank you starrs, Brian_in_Charalotte, jamie99, inspired explorer, & Gretchen for helping me make a decision.

I would pick spring. Have been to this area both seasons, and early fall has always been oppressively humid.