How much can a body of water boost a zone? I know it can boost a zone by a letter and in some cases, a whole number, but can it boost more? Could small islands in large lakes in central Florida could go from 9b to 11a and make a Tropical micro climate? What do you think. 

Small islands in a lake in Central Florida won't go from 9b to 11a, but it does help a lot... There's one weather station I've been keeping an eye on around here on Twin Lake that seems roughly 3f warmer than the surrounding area. Twin Lake is pretty small too, I could see a 5f+ gain a lake that is bigger. 

The answer to your question can be found on the USDA hardiness interactive map when studying the areas around the great lakes and how Lake Pontchartrain affects New Orleans.

We have several large reservoirs around the Dallas/Fort Worth metroplex and none of the areas around the reservoir are warmer than the Urban areas of Dallas on our coldest days. Concrete trumps water where I am at.

Not sure but I think the Pacific Ocean has some effect on the West Coast

No way 9b to 11a imho, but I can see .5 zone, sure. Here on the west coast, it's not just the pacific keeping us from freezing - It's that 13,000+ ft mountain range keeping the "real" cold to our east

5 minutes ago, NorCalKing said:

No way 9b to 11a imho, but I can see .5 zone, sure. Here on the west coast, it's not just the pacific keeping us from freezing - It's that 13,000+ ft mountain range keeping the "real" cold to our east

That's a good point about the mountains. I've come to realize the southeastern US is a lot colder than it probably should be since there aren't any significant mountain ranges seperating us from the arctic tundra in Canada.

Edited September 13, 20169 yr by RedRabbit

4 minutes ago, RedRabbit said:

That's a good point about the mountains. I've come to realize the southeastern US is a lot colder than it probably should be since there aren't any significant mountain ranges seperating us from the arctic tundra in Canada.

Exactly! There's no way we should be growing what we do out here, without those mountains preventing the polar vortex, and dips in the jet stream. If you guys had a northern mountain range everything south of the Carolinas would be 10+ easily.

Edit: Quick example, I'm at 37 degrees lat. My ALL-TIME low 18f

Edited September 13, 20169 yr by NorCalKing

2 minutes ago, NorCalKing said:

Exactly! There's no way we should be growing what we do out here, without those mountains preventing the polar vortex, and dips in the jet stream. If you guys had a northern mountain range everything south of the Carolinas would be 10+ easily.

Edit: Quick example, I'm at 37 degrees lat. My ALL-TIME low 18f

Wow. I'm at 28N and my low is probably lower than that... It isn't just California though, southern Europe seems to be protected by the Alps. A fellow PTer was just saying last week that the all time low in Malta is something like 33F, but they're at 35.5N! I think much of India is the same way too... 

If you took Hilton Head Island and moved it 100 miles east out into the ocean, do you think it would be at least zone 10b? Since the golf stream is there?

Edited September 13, 20169 yr by PalmTreeDude

21 minutes ago, PalmTreeDude said:

If you took Hilton Head Island and moved it 100 miles east out into the ocean, do you think it would be at least zone 10b? Since the golf stream is there?

That's essentially the case with Bermuda.

2 hours ago, PalmTreeDude said:

If you took Hilton Head Island and moved it 100 miles east out into the ocean, do you think it would be at least zone 10b? Since the golf stream is there?

Yes.

 

On ‎9‎/‎12‎/‎2016‎ ‎7‎:‎47‎:‎15‎, RedRabbit said:

That's a good point about the mountains. I've come to realize the southeastern US is a lot colder than it probably should be since there aren't any significant mountain ranges seperating us from the arctic tundra in Canada.

Why can't the Rockies just run East-West...

The gulf stream is about 45 miles offshore here, so yeah probably.

2 hours ago, Laaz said:

The gulf stream is about 45 miles offshore here, so yeah probably.

I wish the gulf stream was closer to shore, I bet the whole east coast would get a big boost! Florida would have very few areas that would be below 10a, if that were the case.

Edited September 14, 20169 yr by PalmTreeDude