Happy Valley, Oregon Weather: December 2018
TEMPERATURES It was a very mild month as temperatures were consistently above normal (22 total days averaged above normal at the Portland Airport, with all but 2 such days after December 10th). The middle of the month was the warmest. Splitting the month into thirds the following Max/Min/Mean Temperatures were observed: 1st-10th 43.6°/35.8°/39.7°; 11th-20th 52.6°/42.5°/47.6°; 21st-31st 45.6°/39.0°/42.3°. As is typical for this area in December, due to the more regular cloud cover, the diurnal range was quite low, averaging only…