Yes according to the Arbor Day foundation map that they revised a few years ago, we've been z8 for quite some time. It also makes a large portion of z9 a z10 which greatly reduces the potential planting range for the trees they are selling but I don't know if it opens any doors for people with cold hardiness issues as opposed to chill requirements & heat.
That map and the various other maps on the net are not in agreeance but it probably is pretty accurate. The other day on the news, they said there was a day in 1985 with a low of minus 8.

It seems like I can remember a time in the 80s with a sub-zero temperaure. The lowest temp so far recorded for the city of Atlanta was -9F in February 1899. Here is an excerpt from a book I have about weather....

"The greatest cold wave in modern US history(modern meaning during the period of U.S. Weather Bureau record keeping) occured during the first two weeks of February in 1899. For the first and only time, temperatures fell below zero in every state of the union, including Florida, where Tallahassee dropped to an unbelievable -2F. In Mobile, Alabama the reading of -1F was a full 13 degrees colder than the previous record low of 12F."(Extreme Weather by Christopher Burt)

The book goes on to note that lowest temperature recorded in the state of Georgia was a -17F reading on January 27, 1940 at the CCC camp F16 in Lafeyette.

I remember the -8 in the 80's. The inside of my french doors was covered with ice. The gas pressure kept dropping and we had to keep trooping down to the crawl space to relight the furnace. Miserable temperatures.

The -8 temp was recorded at the Atlanta airport. PDK recorded -10 and it was -12 at my house. That occurred on Jan 21 & 22, 1985, 2 successive nights. A gardeners nightmare come true.
Rb

Zone 8 is down to 10. I remember it being 5 at one point here 2 winters ago.

I will not be getting any (expensive) zone 8 plants.

I'm used to thinking of Woodstock as being zone 7, and I can't see why I should change. But I guess I bend the rules anyway. I keep telling my pineapple sage that it will be not be that cold, and so far it's believed me!

Does anyone else have a hard time believing records from the 1800's? Not saying it isn't true but the records from the 1800's don't seem to make many repeat performances in the 1900's. Kinda makes you wonder.

I read a few months ago that the 17th, 18th, and 19th centuries were part of a mini ice age. There was no further explanation. I'd love to know more about that. I wonder if that accounts for any of the discrepancies between the 1800's and the 1900's? Anyone know?
I do know it's awfully warm for New Year's day, and I'm not complaining.

Maybe our instrumentation, technology and record keeping/sharing has improved since Sherman's march to the sea. LOL.

I'm not debating global warming but you'll come across statistics to the tune of the temperature of the earth has risen one degree since 1801. Come on now..How does anyone know that?

'Maybe our instrumentation, technology and record keeping/sharing has improved since Sherman's march to the sea. LOL.'

Yankee ingenuity:)

Someone asked about "The Little Ice Age." In regards to that, this is what I know. It occurred between the mid 1600's and mid 1800's. During this time, official weather records were not recorded like they are today, but we do know that it was remarkably cold. Remember that Washington had to cross the FROZEN Delaware River. When was the last time it was cold enough for that to happen? Andersonville, Ga (a Civil War prison camp located in Southwest Georgia between Americus and Montezuma) actually recorded having quite a bit of snow!

Why did all of this happen? Well, we know that the climate naturally experiences fluctuations through time... some sudden and sharp, and others very gradual. In any event, there are long and short periods of dramatically cooler and hotter weather for this earth. The long-term climate for the earth has still yet to be figured out. In fact, so has the short-term climate (which is the reason why weather can't be accurately forecasted 10 days in advance and beyond). Recent theories, as you know, have been focused towards human intervention as a cause of the current increase in the earth's temperature. This is why everyone has been concerned about this theory named Global Warming. Well, humans most certainly did not cause The Little Ice Age, nor did they cause any previous fluctuations in the earth's climate. This is a reason why people need to be more open to the possibility that we humans may in fact have nothing at all to do with this said Global Warming.

What then could be powerful enough to cause a vast difference in climate for such events as the Little Ice Age? Something MUCH more powerful than human activities could very well be a much more significant factor... the sun. The sun is what astronomers classify a G star, which is one of fairly moderate temperature as stars go, but certainly powerful enough to cause a major impact in our weather (in astronomy's eyes, our distance to the sun is still very close). It has burned up Hydrogen to the point that it's lifetime is halfway over (don't worry, unless you live 5 billion more years, you wont see it's end). Something not fully understood by us yet is its solar-magnetic cycle. You may be familiar with "sun spots," which are areas about the size of the earth (and you can fit about a million earths in the sun) that are slightly cooler than the rest of the sun's surface. They last a few months before disappearing. What we do know is that these play a part in its magnetic cycle, which is a very regular cycle that lasts 22 years (every 11 years is a cycle that occurs with one magnetic pole up top, and then swaps to the bottom for the next 11 years). In this 11 year time-span sun spots appear in larger numbers and frequency at the beginning of the cycle, then die down until the magnetic poles swap.

These cycles have been very consistent over time... EXCEPT during The Little Ice Age. Thanks to various astronomers around the world, we know that sun spots didn't appear from the mid 1600's until they appeared again in the mid 1800's, which are the same years as this ice age. I don't think anyone has definitively proven this to be the cause of the Little Ice Age, but it sure brings up a strong and interesting case.

I apologize for this being so lengthy, but I guess there is no easy way to answer the question, since nothing has been definitively proven. I do not want to discredit anyone else's theories on fluctuations in climate, but I would love to see someone focus on researching the sun's involvement in such factors.

The newest zone map is pretty close to the one PRIOR to 1990. If anyone has an old gardening guide from the 80's, they'll see the similarity.

Since 1899, the coldest temps were recorded in 1985, as mentioned above. Recently in Atlanta, temps below 10 were recorded in 1994, 1996, and 2003. Still, the area lands at about 10ºF as a minimum, when averaged over 30 years.

OK, here's the OLD map.

Even though I am not actually within the Atlanta city limits, my weather records indicate single digits lows in the same years you mention Alex. I have complete records since 1/1/1997 and scattered records since 1/8/1994. My lowest temps are as follows:

January 19, 1994: 6F
February 5, 1996: 7F
January 24, 2003: 9F

In comparison the lowest temp I had during winter last year was 22F. So far this year, 17F

the zone boundaries have gone in the wrong direction. global warming is a myth . i live in zone 4 but minimum temps reached a zone 3. global cooling is actually taking place

This is a very interesting discussion. I live in White (the city, not the county), and have been keeping track of the temperatures for the last few years. The new hardiness map is definitely on target, as the lowest it has been since I've been keeping track is 10 degrees, which is where zone 7 meets zone 8.

I think that it's already time for the american horticultural society to update their map, because they list us as a zone 7, but for the last few years we have truly been an 8.

It's freaky how things are changing. The first week of march this year, it snowed and the snow didn't melt on my back deck for 3 days. all of the sudden less than a week later, it was about 81 degrees and the bugs were already out. The plants have been growing like crazy since then. I pray we not have a late frost!