December Weather in Santa Rosa

Last updated: March 2, 2024

The weather in Santa Rosa, United States, during December is characterized by an average temperature of 9°C (48°F). Highs can soar to 20°C (68°F), while lows may dip to -1°C (31°F). Typically, the humidity level in Santa Rosa throughout December hovers around 84%.

-1°C (31°F)

Minimum temperature

9°C (48°F)

Average temperature

20°C (68°F)

Maximum temperature

84%

Humidity

Precipitation and Sunshine hours

In December, Santa Rosa averages 101 mm (4.0 inches) of rainfall, typically over the course of 8 rainy days. The month enjoys an average of 9 hours 30 minutes of daylight, with the sun shining for approximately 5 hours 57 minutes each day. Additionally, there is a 35% probability of sunny days during this period.

101 mm (4.0 inches)

Precipitation

8 rainy days

Rainy days

5 hours 57 minutes

Sunshine hours

35%

Chance of sun

UV Index

In December, the UV Index in Santa Rosa reaches a maximum of 3, indicating a level of Moderate exposure. The most intense UV radiation typically occurs between 12:00 and 14:00, during which unprotected skin may burn in as little as 30 minutes.

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00
UVI	0	1	1	2	2	3	2	2	1	1	0	0	0
Exposure	Low					Moderate	Low
Time to burn	45 min					30 min	45 min