Any noticeble differences in ground temperature in SC and FL (USA)?

That is, after about the first foot.

The background:

I have a relative who has an in-ground pool (central South Carolina). He placed a *blue tarp over it during the summer to keep most of the debris, critters, etc. out. As this is mostly a vacation home, he would visit it only ever several weeks during the summer. Each time, the results were the same: crystal clear water, scalding hot the first six or so inches, an ice-cold below that. OK, that’s a little hyperbolic, but you get the idea.

One of his relatives, who also has an in-ground pool in a vacation home (central Florida), that is also unoccupied for weeks at a time wondered about trying the same thing. Is there any reason to expect anything different: Really cold water after the first several inches or so?

*Unrelated question: Why are tarps typically blue?

at 8 feet below the surface, pretty much anywhere in the continental US, the ground temperature is between 58 and 60 degrees.

So an in ground pool will need sunlight and insulation to stay warm. In florida it will get more direct sunlight. (better light angle, longer day)

The insulation factor is imporant. Straight concrete or sand will not do much to insulate compared to any form of a foam bed between the pool and the surrounding ground.

More importantly - somebody has a vacation home in the middle of South Carolina? Really? Are they vacationing from Kansas and afraid they might see an ocean or mountain?

I’m guessing it’s on Lake Murray.

A clear cover would retain the most heat and allow the radiation (light) in to further heat the pool to the full depth.

Most pool tarps are blue because people equate blue to water. Simple Marketing.

I can’t confirm the statement that most tarps are blue - but if so, then its simply the marketshare of the pool-tarp bleeding into multifaceted marketing of the same product into other uses/markets.

All of my tarps are green or brown, but I don’t own a pool. When I did own a pool, the pool cover was black.

More to the point of the question though, the second relative was hoping for the same frigid temperatures in central FL that were observed in central SC.

Then a light colored tarp/cover would probably do the trick. More ground temperature + less light heating the water = cooler water.

I know that my mom’s uncovered, in ground pool in north Florida stayed bathtub warm from June through August, at least.

From my experience, summers in FL and summers in SC are about the same temp/humidity. Except Florida summers last from April 1 to October 31, whereas SC summers are circa May 15 to September 25.

Back that up. Here in North Florida, our average date of last frost occurs around March 10. For Central Florida, it’s probably more like Feb. 1. Ish. I haven’t seen a freeze in March for years, and usually declare the opening of gardening season to be around Valentine’s Day. Central Florida is quite a bit south of me and warms up earlier than here. Stays warm later as well; North Florida rarely gets frost before Thanksgiving. Central Florida probably doesn’t get frost much before mid-December.

For Central Florida, I’d call “summer” Feb. 1 - December 1.

Seriously.

What is this “frost” you speak of? :slight_smile: I’m just talking about the time period when it is hot as hell, not a frost-free period. That’s year round down here…