Plum blossoms

I was out for a walk yesterday in Umegaoka and came across plum trees in bloom along a pedestrian walkway.  In bloom in early December?  What??  I knew that plum trees bloom earlier than cherry trees (a seasonal event often written about by the great Japanese haiku masters) but these December blossoms kind of baffled me.  Cherry trees typically start blooming in March or February in Japan (and along BC's coast) and I was under the impression that plum trees bloom in February or January at the earliest.

And what's more, it was cold enough to snow in Tokyo in November, marking the first November snowfall in 54 years and also the first November snow-on-ground measurement since 1875 - the Meiji era!  So these plum trees have already had to contend with unusually early winter weather.  But, December has been warm with a few days pushing close to 20 degrees Celsius.  Just warm enough I guess...