December Weather in San Diego, Mexico

Last updated: April 22, 2025

Experience the vibrant December weather in San Diego, Mexico, where temperatures offer a delightful range. Maximums reach 34°C (93°F), ensuring plenty of sunshine for outdoor activities, while average temperatures hover around 24°C (75°F), providing a comfortable climate. As the nights cool down, you might encounter minimums dipping to 10°C (51°F). December also brings a modest precipitation amount of 25 mm (1.0 in) over approximately 5 days, enhancing the region's lush landscapes. With humidity levels at 88%, visitors can enjoy a refreshing atmosphere that captures the essence of this picturesque coastal city.

December Temperature in San Diego

In December, San Diego, Mexico, showcases a delightful climate as it transitions into the cooler months, with minimum temperatures dipping to 10°C (51°F) but maintaining an inviting average of 24°C (75°F). As the month progresses, the highs can reach up to 34°C (93°F), ensuring that residents and visitors alike can still enjoy outdoor activities in a pleasant, sun-drenched environment. This month marks a notable dip from the sweltering heat experienced in summer, yet it remains warmer compared to the colder months seen in many other regions. With such a moderate climate, December in San Diego is perfect for enjoying the beautiful coastal scenery while basking in the inviting warmth.

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

The chart illustrates December temperature patterns in San Diego, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec747880838482838382807775
Data source: Temperature data for San Diego generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in San Diego

In December, San Diego, Mexico, experiences a noticeable decline in precipitation, receiving just 25 mm (1.0 in) of rain across 5 days. This marks a shift from the wetter months preceding it, with November's 53 mm (2.1 in) and notably higher totals in the summer peak. As the year draws to a close, the climate in December becomes drier, reflecting a pattern where precipitation gradually diminishes from the heavy rains of June and July to the milder autumn and winter months. This trend highlights San Diego's distinctive seasonal climate, offering a respite from the rain as the region prepares for the drier January ahead.

December Precipitation Trends in San Diego

The chart displays monthly precipitation patterns in San Diego, 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.
JanFebMarAprMayJunJulAugSepOctNovDec301082654192681031281295325
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

December Humidity in San Diego

In December, San Diego, Mexico, experiences a significant moisture buildup, with humidity levels holding steady at 88%—the same as in November. This peak, reminiscent of the high humidity in September, marks the transition into the cooler months. As the year progresses, a noticeable trend emerges: humidity tends to rise towards the end of the year, beginning from a more comfortable 64% in April. The gradual increase toward winter hints at the coastal climate's influence, providing a lush backdrop for the city as it wraps up the year. Overall, December's humidity reflects a persistent embrace of the wet season, offering an inviting atmosphere for holiday festivities.

December Average Humidity in San Diego

This chart illustrates the average monthly humidity levels in San Diego, 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.
JanFebMarAprMayJunJulAugSepOctNovDec85%80%69%64%63%62%65%78%86%87%88%88%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in San Diego

As December settles in San Diego, Mexico, residents and visitors can expect a UV Index of 8, placing it in the very high exposure category with a burn time of just 15 minutes. This month marks a slight decrease from the previous months, where the UV Index consistently hovered between 11 and 13 during the late spring and summer, reflecting an extreme risk level. However, caution is still advised, particularly for those enjoying outdoor activities, as year-round, San Diego tends to maintain a notable level of UV exposure. Given these trends, it's always wise to stay informed and protective, regardless of the season. For more detailed insights, check out the San Diego UV Index.

Maximum UV Index Levels in San Diego for December

The chart shows the monthly maximum UV Index (UVI) for San Diego 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.
JanFebMarAprMayJunJulAugSepOctNovDec911131313131312121198
Data source: San Diego 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 Diego

As December rolls into San Diego, the city basks in a delightful average of 288 sunlit hours, making it a perfect destination for those seeking warmth and brightness at the year’s end. While December experiences fewer sun hours compared to the peak months of May (328 hours) and March (316 hours), it still offers a significant glow, outshining January’s 224 hours. This gradual increase from winter's start allows residents and visitors alike to savor a magnificent blend of crisp air and vibrant sunshine, showcasing San Diego's unique charm as the year winds down. With consistent warmth throughout the fall, the sunny spell in December is a delightful harbinger of the sunny days to come in the new year.

Monthly Sunshine Duration in San Diego: December Highlighted

The December sunshine duration represents the total number of hours San Diego 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.
JanFebMarAprMayJunJulAugSepOctNovDec224h270h316h312h328h271h316h314h291h275h282h288h
Data source: San Diego December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in San Diego During December

In December, San Diego, Mexico, enjoys a promising likelihood of sunny weather, with a 63% chance of sunshine lighting up the skies. This trend reflects a slight increase compared to the previous month, November, which holds a 58% chance, indicating that the holiday season tends to bring more favorable weather. As the year progresses, it becomes evident that sunny days are more common during these final months, especially compared to the cooler and cloudier summer period. December's sun-soaked potential is enticing for visitors and locals alike, promising idyllic weather to bask in as the year draws to a close.

Percentage of Sunny Days in December in San Diego

The chart illustrates the percentage of sunny days in San Diego 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 Diego experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec41%62%66%57%41%30%42%50%32%47%58%63%
Data source: San Diego December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in San Diego in December

In San Diego, Mexico, December brings a gentle decline in daylight, with just 10 hours of sunshine, marking the shortest days of the year. The daylight duration begins at 11 hours in January and February, gradually increases through the spring months of March and April to reach 12 hours in May. As summer approaches, the days peak at 13 hours between June and July, offering ample sunlight for outdoor adventures. However, as autumn sets in, daylight starts to wane again, returning to 11 hours in November before tapering off in December. This cyclical pattern of light serves as a reminder of the seasonal changes, allowing residents and visitors to plan for the sun's ebbs and flows throughout the year.

Average Daylight Hours in San Diego for December

The chart illustrates the variation in daylight duration in San Diego throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec11h 4m11h 29m12h 2m12h 36m13h 4m13h 17m13h 10m12h 45m12h 13m11h 39m11h 10m10h 56m
Data source: San Diego daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in San Diego

As December arrives in San Diego, Mexico, the wind begins to pick up slightly, averaging 2.5 m/s (6 mph). This marks a gentle transition from the calmer breezes of earlier months. From a low of 1.7 m/s (4 mph) in October, wind speeds gradually increase, reflecting a trend seen throughout the year where the winds are more favorable in the winter months compared to the late fall. Interestingly, the months leading up to December, particularly April through July, consistently maintain an average wind speed of 3.1 m/s (7 mph), suggesting that summer brings a refreshing strength to the air. As the temperatures cool, the wind not only enhances the coastal charm but also invites an invigorating experience for both locals and visitors alike.

Average December Wind Speed in San Diego

The chart displays monthly wind speed patterns in San Diego, 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.
JanFebMarAprMayJunJulAugSepOctNovDec2.42.83.13.13.12.82.52.42.31.72.02.5 m/s
Data source: San Diego December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in San Diego Compares to Other Months

The weather in San Diego 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 Diego and find detailed weather information for every month.

In December, temperatures range from a minimum of 10°C (51°F) to a maximum of 34°C (93°F), with an average of 24°C (75°F). The month sees around 25 mm (1.0 in) of precipitation over five days, accompanied by relatively high humidity at 88%. In contrast, January experiences slightly warmer conditions, with a minimum of 11°C (52°F) and a maximum of 38°C (101°F), while maintaining an average temperature of 23°C (75°F). Precipitation increases to 30 mm (1.2 in) but occurs over just four days, and humidity drops slightly to 85%. For more detailed insights on the weather, you can check San Diego weather in January.

In December, the weather tends to be warm with temperatures ranging from a minimum of 10°C (51°F) to a maximum of 34°C (93°F), averaging around 24°C (75°F). The month experiences about 25 mm (1.0 in) of rainfall over approximately five days, coupled with high humidity at 88%. In contrast, February sees slightly warmer conditions, with temperatures ranging from 10°C (50°F) to a maximum of 36°C (97°F) and an average of 25°C (78°F). This month also enjoys less precipitation, totaling just 10 mm (0.4 in) over three days, and a slightly lower humidity level of 80%. For more detailed insights on the weather, you can check out San Diego weather in February.

In December, temperatures range from a minimum of 10°C (51°F) to a maximum of 34°C (93°F), with an average of 24°C (75°F). The month experiences about 25 mm (1.0 in) of precipitation over five days and high humidity at 88%. In contrast, March sees warmer conditions, with temperatures ranging from a minimum of 14°C (58°F) to a steamy maximum of 37°C (98°F), averaging 27°C (80°F). Precipitation drops significantly to just 8 mm (0.3 in) on only one day, and the humidity decreases to a more comfortable 69%. For a closer look at March weather patterns, visit San Diego weather in March.

In December, the weather features a comfortable temperature range, with a minimum of 10°C (51°F) and a maximum of 34°C (93°F), bringing an average temperature of 24°C (75°F). The humidity is quite high at 88%, accompanied by about 25 mm (1.0 in) of precipitation spread over 5 days. In contrast, April shows a noticeable increase in both temperature and warmth, with minimums of 16°C (61°F) and maximums reaching a blistering 40°C (104°F), and an average of 28°C (84°F). Although April has a slightly higher precipitation level of 26 mm (1.0 in) over 5 days, the humidity decreases significantly to 64%, contributing to a drier feel overall. For more details, check San Diego weather in April.

When comparing the weather in December and May, notable differences emerge in temperature and humidity levels. December sees milder temperatures with a minimum of 10°C (51°F) and an average of 24°C (75°F), peaking at 34°C (93°F). In contrast, May experiences warmer temperatures, with a minimum of 18°C (65°F) and an average of 29°C (85°F), reaching a high of 39°C (102°F). Additionally, December has higher humidity levels at 88%, while May's humidity is considerably lower at 63%, offering a more comfortable feel. Precipitation is also more pronounced in May, with 54 mm (2.1 in) over 9 days, compared to December's 25 mm (1.0 in) spread over 5 days. For more details on the weather, you can check San Diego weather in May.

December and June showcase striking contrasts in weather. In December, temperatures range from a minimum of 10°C (51°F) to a maximum of 34°C (93°F), with an average of 24°C (75°F). The month experiences relatively low precipitation, totaling 25 mm (1.0 in) over about 5 days, accompanied by high humidity levels at 88%. In contrast, June sees warmer temperatures, with a minimum of 22°C (72°F) and a maximum of 38°C (101°F), averaging around 28°C (83°F). Precipitation significantly increases to 192 mm (7.5 in) over 17 days, while humidity drops to a more comfortable 62%. For more details on weather patterns, check out San Diego weather in June.

December and July present contrasting weather conditions. In December, temperatures range from a mild 10°C (51°F) at night to a comfortable average of 24°C (75°F) during the day, with highs reaching up to 34°C (93°F). This month experiences relatively low precipitation of 25 mm (1.0 in) over about 5 days, accompanied by high humidity levels at 88%. In contrast, July brings warmer temperatures with a minimum of 22°C (72°F) and an average of 28°C (83°F), peaking at 38°C (100°F). The month sees significantly higher rainfall, totaling 68 mm (2.7 in) across 14 days, along with lower humidity at 65%. For more details, check out San Diego weather in July.

December and August offer contrasting weather experiences. In December, temperatures range from a mild 10°C (51°F) at night to a warm 34°C (93°F) during the day, with an average of 24°C (75°F). The month sees relatively low precipitation at 25 mm (1.0 in) over just 5 days, and humidity levels are quite high at 88%. In contrast, August features higher temperatures, with nightly lows around 21°C (71°F) and daytime highs reaching 37°C (99°F), averaging at 28°C (83°F). Rainfall significantly increases in August, totaling 103 mm (4.1 in) across 18 days, and the humidity is lower at 78%. For more detailed information about weather conditions, you can refer to San Diego weather in August.

When comparing the weather in December and September, notable differences emerge in both temperature and precipitation. December tends to be milder, with minimum temperatures around 10°C (51°F) and maximums reaching 34°C (93°F), while the average remains a comfortable 24°C (75°F). In contrast, September experiences higher temperatures, with a minimum of 22°C (71°F) and maximum soaring to 37°C (98°F), resulting in a warmer average of 28°C (82°F). Furthermore, September sees significantly more precipitation, with 128 mm (5.0 in) over 21 days compared to December's 25 mm (1.0 in) across just 5 days. Despite the slight increase in humidity during September at 85%, December's humidity is relatively high at 88%, contributing to a different overall feel. For more details, you can check out San Diego weather in September.

In December, temperatures range from a minimum of 10°C (51°F) to a maximum of 34°C (93°F), with an average of 24°C (75°F). The month sees relatively low precipitation, totaling 25 mm (1.0 in) over just 5 days, while humidity remains high at 88%. In contrast, October experiences warmer temperatures, with a minimum of 16°C (62°F) and a maximum reaching 36°C (97°F), averaging 27°C (80°F). However, it significantly sees more rainfall, accumulating 129 mm (5.1 in) over 21 days, while humidity is slightly lower at 87%. For more specific insights about October weather, explore San Diego weather in October.

In comparing the weather of December to that of November, we see a slight drop in minimum temperatures, with December starting at 10°C (51°F) compared to November's 13°C (55°F). Both months have similar maximum temperatures peaking at 34°C (93°F), but December boasts a slightly lower average temperature of 24°C (75°F), just a degree lower than November's 25°C (77°F). Precipitation levels also differ, with December receiving only 25 mm (1.0 in) over 5 days, whereas November sees higher rainfall of 53 mm (2.1 in) spread across 11 days. Interestingly, humidity remains constant at 88% throughout both months. For further insights on November weather, you can visit San Diego weather in November.

Compare San Diego's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in San Diego

As December graces San Diego, the weather transforms into a more refreshing experience compared to the scorching summer months. With pleasant average temperatures around 24°C (75°F) and cooler nights dipping to about 10°C (51°F), visitors can relish mild days while enjoying outdoor activities. While December sees a modest amount of precipitation with a handful of rain days, the overall humidity remains relatively high, lending a crisp edge to the air. This charming month stands out for its balance of warmth and coolness, making it an ideal time to explore the city's scenic landscapes. For a deeper understanding of San Diego's atmospheric patterns, visit San Diego Climate.