High cirrus clouds create colorful sunsets, local temps drop quickly

November’s and December’s Vividly Colorful Sunsets and sunrises are no accident. This is the time of year when high cirrus clouds, often the precursors of storms, sweep through our area with some regularity. When cirrus or other lofty clouds are present, low-angle sunlight bathes their undersides s in a crimson luminescence. This effect is most noticeable a half hour to a few minutes before the sun rises and a few minutes to a half hour after the sun sets.

A perfect winter's day in the hills near Julian. November 2014

Local Temperatures should be declining most rapidly during this time of year, according to more than a century of local meteorological records. With every successive week, daily maximum temperatures are declining by about 3/4° Fahrenheit, and daily minimum temperatures are plummeting by about 1° Fahrenheit. (This gradual onset of fall/winter chill is probably all but unnoticed by most newcomers from harsher climates.) By January, our mean temperature will have fallen to about 55° Fahrenheit, from an average temperature of about 70° Fahrenheit in August.

Floss Silk Tree

gardeningknowhowcom

The Floss Silk Tree, a conspicuous “autumn bloomer” here and there around San Diego, has been showing off its pinkish or purplish hibiscus-like flowers for at least a month now. The broad, heavy trunk of this South American import, which is studded with fat, cone-shaped spines, makes it easy to identify.