December is the most wet month of the year. as of 9:00 am PST. Average Weather in December in Cupertino California, United States. ... December Temperature Outlook. Cupertino Weather for December 2019. Averages are for Moffett Field, which is 7 miles from Cupertino. The amount of rain in December is high with an average of 115mm (4.5in). Information about regional climates. The lowest daily average high temperature is 57°F on December 27. Hi/Low, RealFeel®, precip, radar, & everything you need to be ready for the day, commute, and weekend! In terms of daylight, this day is 5 hours, 9 minutes shorter than on June Solstice. Get the forecast for today, tonight & tomorrow's weather for Cupertino, CA. Daily high temperatures decrease by 3°F, from 60°F to 57°F, rarely falling below 52°F or exceeding 66°F. Weather in Cupertino in December: air temperature, number of sunny days, precipitation, air pressure and humidity. There are 61.4 rainy days annually in Cupertino, which is … The highest monthly average temperature in Cupertino for July is 67 degrees; The lowest monthly average temperature in Cupertino for January is 50 degrees; The most monthly precipitation in Cupertino occurs in December with 2.6 inches; The air quality index in Cupertino … Based on weather reports collected during 1985–2015. The average minimum temperature (usually the minimum temperature is noted during the night) in Cupertino in December is 8.0°C (46.4°F). In most locations north of Equator, the shortest day of the year is around this date. ☂ Online precipitation map and other weather maps. C° F° Weather forecast in mobile app. Hourly Weather-Cupertino, CA. Annual Weather Averages Near Cupertino. Average Weather during December in Cupertino (California), United States of America. December Solstice (Winter Solstice) is on Monday, December 21, 2020 at 2:02 am in Cupertino. December is the rainiest month in Cupertino with 10.3 days of rain, and July is the driest month with only 0.2 rainy days. 2017 2018 2019 2020. Montly weather forecast in Cupertino on Yandex.Weather. Get the monthly weather forecast for Cupertino, CA, including daily high/low, historical averages, to help you plan ahead.