Mine is only a small fan heater, and it got packed away for the warmer weather about 6 weeks ago.
Denver. Not yet; maybe tonight. Thank goodness it’s not snowing here. Yet.
This is pretty late. I get really crabby when it comes on in Sept., but it usually does, so this is a good year, and yet, it’s snowing in the mtns.
San Francisco - we had the furnace on a few days during the “summer”, but not lately. Weather’s been generally very pleasant in September and October.
The thermostat is set the same all year round, so I don’t do anything in particular unless I happen to kick it up a couple of degrees to make it come on when it wouldn’t otherwise. It might start coming on by itself early in November, depending.
Roddy
No. Phoenix, AZ. I turn the heat on in December/
Oh, I forgot about those of you on the “other” side of the world. 
It’s just getting warmer now instead of the other way 'round eh?
Today I would have turned on the AC if it wasn’t for the fact that we’re trying not to spend anything.
We’ve had some nice cold nights, but nothing to make us turn on the heat. I did finally put a blanket on the bed (besides the quilt) this week, but we only needed it for a few days. I don’t think we will tonight.
Tucson, here. I’m still running my A/C. When it does get cold enough to turn the heat on, I’ll only run it in the evening. It’s warm enough in the daytime I don’t use it then.
Panama here. I live here because I never, ever, have to worry about turning on the heat.
We didn’t turn it off all summer. Someone wake me up five months - we’ll try it again and see if we actually get a summer next year.
One thing about Calgary is your winter clothes never get packed very far away - we’ve had snow in every month of the year here, and with our chilly nights even in the height of summer, you never put away your jackets, sweaters, and long pants.
Massachusetts. It hasn’t really gotten cold enough outside to turn the heat on but we’re trapped in the shade so my house is really cold, especially at 3am when I’m trying to pull an all-nighter. So, I’ve had a fire going most nights the last week or so.
I did turn the heat on for a day last weekend. Initially it was to test out the new burner but then I never got around to turning it off and since I was up for about 40 hours, I didn’t trust myself to build a fire anyway.
It’s actually unpleasantly warm in my house right now even though the fire went out 3 hours ago and the heat is off.
California; it’s still warm enough that I don’t turn on the heat, I open the window to let in the cool air in the evening.
The last time I turned the heat on was almost 6 years ago, when my son was a newborn baby.
I stopped using the AC last week, though, although we’re expecting a heat wave in a few days, so it’ll probably go back on.
SW Indiana. Even though it’s gotten down into the 30s recently, I refuse to turn on the gas furnace or an electric heater as we have the highest electric and natural gas rates for the entire state.
Don’t want to have the electric bill jump from $200 a month to over $600 a month just yet!!
I did, but didn’t like it and turned it back off.
Tennessee. First needed it one night, about a month ago.
Went down to 47 degrees.
Rarely turn on the heat at all, maybe 5-10 times a year for a **very **limited (as in, a few hours) period.
We’ve just stopped running the A/C all the time… And will probably still need to use it again, at least through October.
Tel Aviv, Israel.
ETA:
You don’t maybe happen to live near where I do…?
No. I usually turn it on in late November or early December.
It started feeling a bit cool towards the end of September, but we resolved we would not turn it on until October. October has felt extremely mild so far, so it hasn’t been necessary yet - probably will be within a week. Bristol, UK here.
New York City. It hasn’t come on yet (and if it had, I would have turned it off). Last night I felt so warm in my apartment I had the window open.
Seattle here, and no. It’s been in the 50s or 60s (AKA: perfect), but we’re the kind of people that keep the windows open a bit even when there’s snow on the ground. We shut the windows and put on fuzzy socks if we get cold, maybe adding a blanket to the bed.