The highest day temperature in December 2025 was 55°F. The lowest night temperature was 20°F. The average values for day and night temperatures during December were 41.3°F и 31.7°F respectivly.

You can expect various weather conditions during December. Be ready for sunny, cloudy or even gloomy days.

Precipitation total in December for Sunriver is 1.0 in. It makes december one of the most rainy months of the year.

The average wind speed in December is 6.8 mph. This value is relatively stable throughout the year.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Sunriver in December is 4.5 hours.