I just realized something the other day which I never really thought about till now. For my zone, the average first fall frost is in summer!

First day of fall = 22nd Sept.
First average fall frost = 21st Sept.

Grumble...

Here in Maine we've had frost warnings for the past 3 nights. Luckily it only got down to 34 degrees here. I brought my potted plants in anyway, and covered the tender stuff.

I already have black basil....frost pocket in NY

Had the first semi-killing frost here in Western Maine last night.

I can't complain, though. When I was back in the Adirondacks, the average date for my area was Sept. 10th. My last year there, we had a last spring frost on June 22nd.

Wayne

Our lowest low so far in our town was about 40. North of here had a light frost a couple weeks ago already. I don't see anything below 40 in the forecast for 2 weeks from now. It can change of course. I actually hope we get frost the first of October so I can sell fall stuff like rutabagas and brussel sprouts after they get sweet. Plus I am super sick of picking beans. Anyone else?

Stop using the F word!!!!!

I keep chanting to myself... "it's still summer... it's still summer"

Denial is bliss.

We are cold and blustery today, hoping to make the week-end but it is coming. mk

Last frost here was early June, but it never really got warm this summer and everything was very slow. Normally the outdoor plants are bearing tomatoes by August 1, but they only started last week and I will probably lose a lot of them tonight. I have covered 16 plants, the ones furthest along. The rest don't really have a chance even if I did cover them, they need at least 20 days and I don't think I'm going to get more than 4-5 before snow seriously flies. Flurries out there right now.

The most bestest place to find out what the Average Date Of First Frost for where you live is your friendly county office of your state universties USDA Cooperative Extension Service. You do need to keep in mind that this is general information and your micro climate can be different from the average.
Normally here I would already have had a killing frost even though the ADFF is in October and a friend that lives 8 miles west, closer to Lake Michigan, has had 3 frosts already while I've not had one.

I realize that the frost date is average, and of course you can get one before the date. But don't they kind of slant the date? Not a true middle of the data.

I mean, our date is September 15, I always think that I am pretty safe up to that date, and blessed every frost free day after that date, but living on borrowed time.

Seldom have we had a frost before the frost date, often we have been many days after the frost date. Just curious. mk

The frost date is an average, going back many years (maybe 50?). If it was a median date it would probably be more accurate. There was supposed to be a "correction" made a couple of years ago to account for the differences in the recent (last 15 yrs I think) weather patterns which would put some of us in a higher or lower zone-(global warming?)-but haven't seen any results. All it really is designed for is to give hottest and coldest temps to determinate which perennials will survive, but the first/last frost dates were thrown in as a "bonus".

The best way to tell when the last and first frost date is - keep your own records. Everyone's location is different. You may have a couple different areas on your own location with different dates.
Years ago when living in the country I had two distinctive locations on my property. One was at or near the west end of the property and the other was at the bottom of the slope on the east end. Reason. cold air drains to the lowest spots.
I could plant cold sensitive crops two weeks earlier on the west end.

Yes, the best way to know your Average Date of First Frost is to keep your own records but that does take several years of data. My records tell me that I shold get a frost around September 5th, but this year I've not had one, yet, and last year there was no frost until September 21st and then some years I may have a frost one day and not again until the end of October so if I'm prepared the frost tender plants can be covered and then can continue growing and producing for another 6 to 8 weeks.
The same can be said for the Average Date of Last Frost, keep your own records but until you have sufficient data to rely on use the USDA data. The USDA Dates have been moved in the last few years because NOAA has fewer reporting stations to gather the needed information.

You folks must have those "Indian Summers" my relatives always talked about, where you get a light frost early, then harvest after that frost.

Anyway....As a Libra, I use my birthday for the earliest last frost date and pray for another 2 weeks until Halloween or early November. I find the info from the extension agency does slant towards the earlier dates. I imagine that they do that so people won't make too many plans for later dates... So it is a pleasant surprise for a longer growing season.

Good luck this year on what Jack Frost will do.

Here along the mighty Mississippi, a couple of miles from the levee in Northeast Arkansas, which is considered the Mid-South, we usually have a light frost or two toward the end of October, and don`t get a good killing frost until the first week or two of November.