Sunrise & Sunset Times in Sunnyvale — December 2025

Sunrise & Sunset in Sunnyvale During December

December contains the winter solstice around the 21st, making it the month with the shortest days and longest nights in Sunnyvale. Near the solstice, the rate of daylight change slows to near zero, creating a stretch of equally short days. The sun sits at its lowest noon altitude, casting long shadows even at midday. After the solstice, days begin to lengthen again — imperceptibly at first, but the turning point marks the start of the slow climb back toward summer.

Golden Hour & Twilight in December

During December, golden hour in Sunnyvale lasts approximately 54 minutes each morning and evening. The low sun angle during these periods produces warm, directional light prized by photographers and filmmakers. Civil twilight — the period when the sun is just below the horizon — adds extra usable light before sunrise and after sunset, extending the practical daylight window beyond the times shown in the table above.

Through December, days in Sunnyvale are shortening by roughly 0.3 minutes per day, adding up to about 0h 9m over the course of the month.

December 2025 Summary — Sunnyvale

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