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January Weather in Santa Rosa, United States

Last updated: June 24, 2025

In January, the average temperature in Santa Rosa, United States hovers around 13°C (55°F). Expect a range where the minimum dips to 0°C (31°F) and the maximum can soar to 28°C (83°F). During this month, the region experiences 18 mm (0.7 in) of precipitation over approximately 2 days, accompanied by an average humidity of 76%.

January Temperature in Santa Rosa

In January in Santa Rosa, the average temperature is 13°C (55°F). Maximums can reach 28°C (83°F), while minimums can drop as low as 0°C (31°F). This variability makes it essential for travelers to pack layers to accommodate both warm and cooler conditions.

January Weather in Santa Rosa: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Santa Rosa, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Santa Rosa, January typically has an average temperature of 13°C (55°F), with highs reaching up to 28°C (83°F) and lows dropping to around 0°C (31°F).
JanFebMarAprMayJunJulAugSepOctNovDec555764737989919186756655
Data source: Temperature data for Santa Rosa generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

January Precipitation in Santa Rosa

In Santa Rosa in January, the precipitation amount is 18 mm (0.7 in) over the course of 2 days.

January Precipitation Trends in Santa Rosa

The chart displays monthly precipitation patterns in Santa Rosa, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Santa Rosa, January typically receives around 18 mm (0.7 inches) of precipitation spread over approximately 2 days.
JanFebMarAprMayJunJulAugSepOctNovDec1818132173424157818
Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.
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January Humidity in Santa Rosa

In Santa Rosa in January humidity is 76%. With an average temperature of 13°C (55°F), this humidity feels like a damp, heavy blanket enveloping you, making it feel cooler than it actually is, which can be quite refreshing for short excursions but may also lead to discomfort during prolonged outdoor activities.

January Average Humidity in Santa Rosa

This chart illustrates the average monthly humidity levels in Santa Rosa, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Santa Rosa is approximately 76%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%79%67%55%40%33%34%48%64%67%77%82%
Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Santa Rosa

In Santa Rosa in January, the maximum UV index reaches 5, which corresponds to a moderate Exposure Category. Under these conditions, the estimated time to burn is approximately 30 minutes. For more details, you can check the Hourly UV Index in Santa Rosa.

Maximum UV Index Levels in Santa Rosa for January

The chart shows the monthly maximum UV Index (UVI) for Santa Rosa in January, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In January, the maximum UV index in Santa Rosa typically reaches 5, which falls under the moderate exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec579111212121110864
Data source: Santa Rosa January UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How January Weather in Santa Rosa Compares to Other Months

Weather in Santa Rosa varies notably across the year, with each month offering distinct climate conditions. This page compares January’s weather to other months in Santa Rosa, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Santa Rosa, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather13°C (55°F)18 mm (0.7 inches)76%moderate
February Weather14°C (58°F)18 mm (0.7 inches)79%high
March Weather18°C (64°F)13 mm (0.5 inches)67%very high
April Weather23°C (73°F)2 mm (0.1 inches)55%extreme
May Weather26°C (79°F)1 mm (0.0 inches)40%extreme
June Weather32°C (89°F)7 mm (0.3 inches)33%extreme
July Weather33°C (91°F)34 mm (1.3 inches)34%extreme
August Weather33°C (91°F)24 mm (0.9 inches)48%extreme
September Weather30°C (86°F)15 mm (0.6 inches)64%very high
October Weather24°C (76°F)7 mm (0.3 inches)67%very high
November Weather19°C (66°F)8 mm (0.3 inches)77%high
December Weather13°C (56°F)18 mm (0.7 inches)82%moderate

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