A Change in Weather: Fall becomes Winter?

Just the other day, Monday to be precise, I was walking around above town thinking about the signs of fall that were all around: dry, straw-colored bunch grass (unknown variety), yellow blooms of rabbitbrush (right foreground), golden-brown blooms of sagebrush (left middleground), and yellow to bright red aspen on the distant mountain.
This closer view of the Duck Creek Range, with Camel Peak to the right, shows the aspens better - a yellow to red patch to the right of the central saddle, just above the folded Cambrian limestone.
Two days later - Wednesday to be precise, because I shot this pic yesterday morning - there was snow on the mountain, and many leaves had fallen off the aspen trees. Today, the snow is mostly gone, except for some patches on north slopes under a few trees.
The same two photos, enlarged, for easier comparison.
Exactly one year ago yesterday, on September 30, 2007, I happened to be at the top of the saddle north of the aspen trees, and I took this somewhat faded-looking photo with my old camera. The same aspen trees - located just above the light gray Cambrian limestone and just below the pointy-looking peak, Camel Peak - had mostly dropped their leaves. Saddle location in Google Maps. Oh, and btw, that's an exposure of mylonitic quartzite in the foreground!

Ah, the vagaries of weather, year to year.

As for our garden, it experienced our first hard freeze (it got down to 14°F at the airport, but was already 39°F when I checked our thermometer at almost 9:00 am, and 32°F at the airport at the same time - we are in the banana belt). The tomatoes have wilted and are falling over, the leaves of our zucchini plant are lying flat on the ground, and the marigold leaves have wilted and turned blackish green. The kale is just fine, and so is the chocolate mint. Yay for the chocolate mint!