December Weather in San Jose, United States

Last updated: February 24, 2025

December in San Jose offers a mild climate, with maximum temperatures reaching up to 24°C (76°F) and an average of 10°C (50°F), providing a comfortable atmosphere for residents and visitors alike. As the month unfolds, the charm of the season is marked by 116 mm (4.6 in) of rainfall over 9 days, contributing to the region's lush greenery. Coupled with a humidity level of 80%, the air feels fresh and invigorating, making December a delightful time to experience the unique beauty of this vibrant city.

December Temperature in San Jose

In December, San Jose experiences a mild and pleasant climate, making it an appealing destination during the winter months. The temperatures range from a minimum of 1°C (34°F) to a maximum of 24°C (76°F), with an average of around 10°C (50°F). This month marks a gentle transition toward cooler weather, contrasting with the warmer peaks reached in the late summer and early fall. As December unfolds, the evenings can be brisk, yet the days still offer a glimpse of warmth, reminiscent of the milder conditions seen in prior months. While the chill may have settled in, the overall temperate range keeps San Jose inviting, perfect for enjoying outdoor activities or festive gatherings.

December Weather in San Jose: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in San Jose, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec505153565964666766635550
Data source: Temperature data for San Jose 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.

December Precipitation in San Jose

In December, San Jose experiences a noticeable uptick in precipitation, with an average of 116 mm (4.6 inches) spread over 9 days. This marks a significant increase compared to the drier months of summer, where July and August receive no rainfall at all. The transition into winter brings back the rains, as December's totals sit comfortably above November's 56 mm (2.2 inches), signaling the onset of the region's wetter season. The consistent precipitation in December not only replenishes local reservoirs but also nurtures the vibrant landscape, preparing it for the flourishing vegetation that follows in the spring. As the year wraps up, those cozy, rain-soaked days invite a sense of renewal, showcasing the dynamic climate of San Jose.

December Precipitation Trends in San Jose

The chart displays monthly precipitation patterns in San Jose, with values for each month alongside December's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec145133114372410132556116
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in San Jose

In December, San Jose experiences a noticeable increase in humidity, with levels reaching 80%. This marks a slight rise from November's 78%, suggesting a trend of higher moisture content as the year comes to a close. As we journey through the months, it's evident that the summer brings drier conditions, peaking in August at a low of 54%. However, as autumn unfolds, humidity gradually climbs, culminating in the late-year spike. This cyclical pattern highlights San Jose's transition from the drier summer months to the wetter winter season, creating a refreshing atmosphere amidst the cooler temperatures of December.

December Average Humidity in San Jose

This chart illustrates the average monthly humidity levels in San Jose, with December's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how December's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec82%84%82%78%71%64%59%54%55%62%78%80%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in San Jose

As December rolls in, San Jose experiences a shift in UV exposure, with the UV Index dropping to 3, indicating a moderate level of risk for sunburn. This reduction brings a welcomed respite from the extreme levels observed in the peak summer months, where the Index soared to 11, requiring protective measures within just 10 minutes of sun exposure. In contrast, December's burn time extends back to 30 minutes, reminiscent of the moderate levels seen at the beginning of the year. Such trends highlight the seasonal variations in UV radiation, reminding residents to remain cautious but also allowing for more leisurely outdoor activities during the cooler winter months. For more detailed information on UV levels throughout the year, check out San Jose UV Index.

Maximum UV Index Levels in San Jose for December

The chart shows the monthly maximum UV Index (UVI) for San Jose in December, 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.
JanFebMarAprMayJunJulAugSepOctNovDec4589111111109753
Data source: San Jose December 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.

December Sunshine in San Jose

December in San Jose offers a delightful respite as the year draws to a close, with 206 hours of sunshine illuminating the city. Although this marks a decline from the sun-drenched summer months, where July shines the brightest with 379 hours, December maintains a commendable amount of daylight compared to earlier winter months. The trend throughout the year showcases a gradual increase in sunny hours, peaking in June and July, before gently tapering off as the days shorten. As festive lights twinkle against a backdrop of crisp winter air, the balance of sunlight in December reminds us that while we may be leaving behind longer days, San Jose still embraces the sun's warmth even in the final month of the year.

Monthly Sunshine Duration in San Jose: December Highlighted

The December sunshine duration represents the total number of hours San Jose experiences direct sunlight during the month of December, excluding cloudy or obstructed periods. This chart compares the sunshine duration of December with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec162h222h269h303h360h373h379h348h310h286h233h206h
Data source: San Jose December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in San Jose During December

In December, the likelihood of sunny weather in San Jose, United States, dips to 40%, marking a significant decrease compared to the sunnier months that precede it. While the city enjoys vibrant sunshine in the summer—peaking at 84% in August—the trend shifts as the year winds down, with each autumn month consistently hovering around the mid-50s. This December pattern suggests a transition into the cooler, cloudier winter season, making it one of the least likely months for sunshine. As the year closes, residents can expect a departure from the radiant days of summer, ushering in the cooler, more overcast skies typical of the festive season.

Percentage of Sunny Days in December in San Jose

The chart illustrates the percentage of sunny days in San Jose throughout the year, with December highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often San Jose experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec44%57%56%56%75%74%75%84%80%58%55%40%
Data source: San Jose December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in San Jose in December

As December arrives in San Jose, daylight begins to wane, providing just 9 hours of sunlight—an echo of January's similar brief days. This seasonal pattern highlights a gradual increase in daylight duration from the winter months through spring, where hours peak at 14 hours in May and June. As summer shifts into autumn, the sunlight retreats, with days shortening steadily until December brings the year’s minimum light. Despite the darkness of December, the cycle of returning sunlight is just around the corner, promising more vibrant days ahead as the calendar turns toward the new year.

Average Daylight Hours in San Jose for December

The chart illustrates the variation in daylight duration in San Jose throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 55m10h 49m11h 59m13h 10m14h 10m14h 39m14h 23m13h 30m12h 21m11h 10m10h 9m9h 38m
Data source: San Jose daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in San Jose

As December unfolds in San Jose, the average wind speed reaches a brisk 2.2 m/s (5 mph), aligning with the trend of moderate breezes seen earlier in the year, particularly in February and May. While the summer months of July and August experienced a dip in wind activity, December marks a resurgence, reminiscent of the early months where wind speeds consistently hovered around 2.1 m/s. This seasonal shift not only adds a refreshing chill to the air but also invigorates the landscape, making outdoor activities more enjoyable. Overall, the wind in December serves as a gentle reminder of the changing seasons, blending seamlessly into the rhythm of San Jose's climate.

Average December Wind Speed in San Jose

The chart displays monthly wind speed patterns in San Jose, with values for each month shown alongside December's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how December's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec2.12.22.11.92.22.11.61.51.62.11.72.2 m/s
Data source: San Jose December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in San Jose Compares to Other Months

The weather in San Jose changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of December's weather with other months, highlighting differences in temperature, precipitation, and other key factors. Click on each section to discover seasonal trends in San Jose and find detailed weather information for every month.

In December, the weather features a minimum temperature of 1°C (34°F) and an average of 10°C (50°F), with a maximum reaching up to 24°C (76°F). This month experiences around 116 mm (4.6 in) of precipitation over 9 days, along with a humidity level of 80%. In contrast, January sees slightly cooler minimum temperatures at 0°C (32°F), with the average remaining consistent at 10°C (51°F) and a maximum of 24°C (75°F). However, January has increased precipitation totaling 145 mm (5.7 in) over 8 days and slightly higher humidity at 82%. For more details, check out San Jose weather in January.

December and February exhibit distinct weather patterns, with February generally being slightly cooler on average. In December, temperatures range from a minimum of 1°C (34°F) to a maximum of 24°C (76°F), while February sees a slight drop with minimum temperatures reaching -1°C (30°F) and maximums at 25°C (77°F). Precipitation is also notable, with December recording 116 mm (4.6 in) over 9 days and February slightly higher at 133 mm (5.2 in) over just 8 days. Humidity levels are comparable, with December at 80% and February at 84%. For more details on February weather, visit San Jose weather in February.

December and March in San Jose present a mild climate, but with some notable differences. In December, the average temperature is slightly cooler, with a minimum of 1°C (34°F) and a maximum of 24°C (76°F), while March sees a marginally warmer average of 11°C (53°F) and a high of 26°C (79°F). Both months experience similar levels of precipitation, with December receiving 116 mm (4.6 in) over 9 days and March having 114 mm (4.5 in) over 12 days. Humidity is almost consistent across both months, at 80% in December and 82% in March. For more detailed insights into March weather, you can refer to San Jose weather in March.

December and April showcase notable differences in weather patterns. In December, temperatures range from a chilly minimum of 1°C (34°F) to a comfortable maximum of 24°C (76°F), with an average of 10°C (50°F). This month experiences higher precipitation at 116 mm (4.6 in) over about 9 days, accompanied by relatively high humidity levels of 80%. In contrast, April warms up slightly, with temperatures ranging from a minimum of 3°C (38°F) to a much warmer maximum of 31°C (88°F) and an average of 13°C (56°F). Rainfall drops significantly to 37 mm (1.4 in) over only 4 days, while humidity remains fairly constant at 78%. For a deeper dive into April weather specifics, check out San Jose weather in April.

In December, temperatures in San Jose typically range from a chilly minimum of 1°C (34°F) to a comfortable maximum of 24°C (76°F), with an average of 10°C (50°F). The month is quite rainy, with about 116 mm (4.6 in) of precipitation over approximately 9 days, alongside a high humidity of 80%. In contrast, May offers significantly warmer weather, with minimum temperatures around 5°C (40°F) and a maximum reaching 32°C (90°F), averaging 15°C (59°F). The month sees much less rainfall, with only 24 mm (0.9 in) over about 2 days, and a lower humidity level of 71%. For a detailed look at San Jose's weather patterns, check out San Jose weather in May.

December and June present stark contrasts in weather conditions. In December, temperatures range from a chilly minimum of 1°C (34°F) to a comfortable average of 10°C (50°F), with a peak of 24°C (76°F). The month experiences considerable rainfall, with an average precipitation of 116 mm (4.6 in) over nine days and humidity levels averaging around 80%. In contrast, June boasts warmer temperatures that vary from a minimum of 8°C (47°F) to a much hotter average of 18°C (64°F), peaking at 37°C (99°F). The month is notably dry, receiving only 1 mm (0.0 in) of precipitation and featuring no rainy days, with humidity dropping to 64%. For more detailed information about June weather, check out San Jose weather in June.

December and July present contrasting weather patterns in terms of temperature and precipitation. In December, temperatures range from a chilly 1°C (34°F) at night to a comfortable 24°C (76°F) during the day, with an average of around 10°C (50°F). This month is characterized by significant rainfall, with approximately 116 mm (4.6 in) of precipitation over about 9 days, leading to a high humidity level of 80%. In stark contrast, July boasts much warmer temperatures, with a minimum of 10°C (50°F) and a sweltering maximum of 34°C (93°F), averaging 19°C (66°F). Notably, July experiences dry conditions, with no recorded precipitation and only 58% humidity. For more details on July weather specifics, you can visit San Jose weather in July.

December and August present contrasting weather patterns in terms of temperature, precipitation, and humidity. In December, temperatures range from a chilly minimum of 1°C (34°F) to a comfortable maximum of 24°C (76°F), with an average of 10°C (50°F). This month experiences significant precipitation, with an average of 116 mm (4.6 in) over about 9 days, contributing to a high humidity level of 80%. In stark contrast, August boasts much warmer temperatures, with a minimum of 11°C (52°F), an average of 19°C (67°F), and soaring maximums reaching 39°C (102°F). Notably, August is remarkably dry, with no recorded precipitation and a lower humidity level of 54%. For more detailed insights into August weather, you can explore San Jose weather in August.

December and September showcase contrasting weather patterns. In December, temperatures range from a chilly minimum of 1°C (34°F) to a comfortable average of 10°C (50°F), with a maximum of 24°C (76°F). The month is characterized by significantly higher precipitation, totaling 116 mm (4.6 in) over about 9 days, and humidity levels reaching 80%. In stark contrast, September experiences milder temperatures, with a minimum of 7°C (45°F) and an average of 19°C (67°F), peaking at a sweltering 41°C (106°F). This month enjoys a much drier climate, with only 3 mm (0.1 in) of precipitation and no rainy days, accompanied by a lower humidity of 55%. For more detailed insights about September weather, you can check San Jose weather in September.

December weather in San Jose is noticeably cooler and wetter compared to October. In December, temperatures range from a minimum of 1°C (34°F) to a maximum of 24°C (76°F), with an average of 10°C (50°F). The month experiences significant rainfall, totaling 116 mm (4.6 in) over approximately 9 days, and boasts a humidity level of 80%. In contrast, October offers warmer conditions with temperatures ranging from a minimum of 5°C (42°F) to a maximum of 34°C (94°F) and an average of 17°C (63°F). Precipitation in October is minimal, only 25 mm (1.0 in) over just 1 day, resulting in a lower humidity level of 62%. For a detailed look at the climate specifics, check out San Jose weather in October.

In comparing the weather patterns of December and November, it's evident that December experiences cooler temperatures overall, with an average of 10°C (50°F) compared to November's warmer average of 13°C (56°F). Both months have the same minimum temperature of 1°C (34°F); however, November can reach a higher maximum of 28°C (83°F) compared to December's 24°C (76°F). Additionally, December sees significantly more rainfall, with 116 mm (4.6 in) of precipitation over 9 days, while November has only 56 mm (2.2 in) over 5 days. Humidity levels are similar, with December at 80% and November slightly lower at 78%. For more insights into November's weather, you can visit San Jose weather in November.

Compare San Jose's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in San Jose

In December, San Jose experiences a notable shift in weather, transitioning into the cooler and wetter months of the year. With a maximum temperature reaching around 24°C (76°F) and an average of 10°C (50°F), the days turn crisp and refreshing. The humidity lingers at a comfortable 80%, while the region sees about nine days of precipitation, totaling around 116 mm (4.6 in). This combination of cooler temperatures and increased rainfall sets December apart from the typically drier, warmer months, making it a unique time to experience the city’s winter charm. For more about how these patterns unfold throughout the year, check out San Jose Climate.