First Frost and Global Warming

We haven’t had a frost yet (and we did not turn the heat on for the first time until Sunday evening, although on some cool nights we’ve had a fire in the fireplace). I’ve been thinking that it was unusual if not unprecedented to be frost-free this late into the fall -- another sign of global warming. For six or so years in the late 1990s I kept track of weather information – high and low temperatures, big storms, first frosts, etc. This morning I pulled out the notebooks in which I jotted down those records. It turns out that in 1995, we didn’t have a frost until October 18. I was under the impression that the first frost always hit in late September or early October, but this might be because the third week of September is when you have to start worrying about your tomatoes getting zapped – not that they will, but that they could.

Here are the first-frost dates from my notebook:

1994 – October 3

1995 – October 18

1996 -- October 4

1997 -- September 25

1998 -- September 24

1999 -- October 8

During those years we lived in New Canaan, on the Pound Ridge border, about 200 yards from a reservoir, which might have protected the immediate area from an early frost. In any case, a first frost during the third week of October isn’t that unusual. Of course the third week of October is half over and there’s no frost in sight yet, so who knows how long it will last. So maybe it is global warming; and since no one with any knowledge is claiming that we're just starting to feel the effects of global warming now, maybe the 1995 record should be attributed to it as well.