On 12/20/2015 1:08 PM, David E. Ross wrote:
This morning, I saw frost on my neighbors' roofs as late as 8:30am.

"Winter chill" is the number of hous the termperature is at or below
45F. I generally measure from 1 November to 31 March. The average for
my area is about 330 hours. Two years ago, however, we got only 127
hours. Last year it was only 102 hours with the first chill occuring
late on Christmas day.

This year seems to be reverting back to normal. Our first chill was in
mid-November. So far, we have had over 50 hours of chill.

Just because we are having a normally cold winter does not mean there is
no human-induced climate change. "One swallow does not make a summer."
(Aristotle)


December is not completely over yet, but we have had more winter chill
November-December (113 hours) than we had entire last winter
November-March (102 hours). By Friday (New Year Day), we might even
exceed the winter two years ago (127 hours).

Yes, I know that winter does not start in November and is over before
the end of March. But my garden responds to chill that occurs from the
start of November until the end of March.

--
David E. Ross
Climate: California Mediterranean, see
http://www.rossde.com/garden/climate.html
Gardening diary at http://www.rossde.com/garden/diary