Agree with what Dan said. I'm surprised that at your altitude they have lasted this long. Tomato plants are pretty much gone or quickly going belly-up in climates much warmer than yours and heavy winds and rains only hurry up their decline.

Dave

I should add that low humidity, which you have, will just make it worse. Leaves are moist inside and permeable, so when the wind blows, the leaf temperature can be quite a bit lower than the air temperature. Like if you're all wet and go out in the breeze. Brrrr.

But what will take out lots of varieties of different freeze intolerant plants essentially simultaneously? A freeze. Boom, they're all done. Probably happened overnight.

Looks like you've done the right thing and grabbed the unripe fruit. The green tomato with the blush will get red on your windowsill.

Add to all that the fewer minute and hours of sunlight since the summer solstice and you can see big changes have actually occured. Sept 21 was the equinox where the Sun is halfway to the minimums of winter. Unless you are pretty far south it cools fast. Even here growing slows in September just due to light reduction.

How much have you been watering them? It could certainly be frost/cold, but the plants just look underwatered to me. Usually frost will make tomato leaves dark in my garden. The fruits do look like they could be frost-damaged.

There are climates at my latitude that get twice as much sunlight as I do, just because of clouds. My plants don't mind. Don't overrate sunlight. All growth slows down when the temperatures fall. Wilting rapidly over 4-5 days isn't about getting less sunlight.

I will quote that one day with your permission Dan. "Don't overrate sunlight". Of course there are myriad factors.

It's really true. Yes, we're told that we must must must get 8 hours of sunlight. Nonsense. If you're trying to achieve optimal plant performance, sure, that helps, but it isn't as if you can't have a great garden with less sunlight. On one of my beds, the sun "rises" at 1pm (because the bed is on the west side of a house). That actually works fine. All my tomatoes are in that bed.

I'm right now having a "discussion" in the veggie forum with someone who thinks that plants stop growing when the day is less than 10 hours long. To the extent it is bitterly cold when the day is less than 10 hours long, that might be the case, but in many locales it isn't.

That is interesting because my home sits on the western side of a hill of hardwoods, so the garden, like yours, is currently in the shade until the lunch hours.