What's with these temps?

It's the middle of October, and it freezes at night?

I came home late Saturday afternoon from the Georgia Master Gardener conference and the first thing I did was turn the heat on. This is not normal! It should be seventy degrees today. Instead, this morning I woke up to white lawns and white roofs. I've been outside the past two days, to take Coleus, Plectranthus and Alternanthera cuttings and I've brought four of my five Walking Irises indoors (the "mother" I put in a gigantic pot a few weeks ago, because it had outgrown the pot it came in last summer, but it's too big for any place in my house [at least, any place that is not a bathroom without windows . . .], so I've got to go and buy another, somewhat smaller, pot for another transplantation and then find a place for it . . . . where? The dining room, most likely. The four "babies", meanwhile, have grown enormously and my friend Pat tells me to keep an eye on them, because they will bloom in January or thereabouts - for one day only.

None of this should be happening now; it should have been possible for us to have another two or three weeks of "normal" autumn weather.