January Weather in San Diego, Mexico

Last updated: April 22, 2025

In January, San Diego, Mexico experiences a dynamic climate characterized by warm temperatures and occasional rainfall. The maximum temperature can reach a sweltering 38°C (101°F), while the average sits comfortably at 23°C (75°F). Visitors can expect a refreshing contrast with nighttime lows dropping to 11°C (52°F). Rainfall during this month totals around 30 mm (1.2 in), spread over approximately 4 days, adding a touch of coolness to the air. With humidity levels reaching 85%, January in San Diego offers a unique blend of warmth and moisture, making it an intriguing destination for travelers seeking diverse weather experiences.

January Temperature in San Diego

January in San Diego, Mexico, offers a delightful range of temperatures that herald the arrival of winter without the chill. With minimums around 11°C (52°F), average daytime warmth reaching 23°C (75°F), and peaks soaring to an impressive 38°C (101°F), it’s a month that caters to those seeking both cool breezes and sunny skies. This trend of mild mornings giving way to warm afternoons continues into February, where temperatures subtly rise and create a pleasant backdrop for outdoor activities. As the months progress, the average daytime temperatures steadily climb, peaking in May with an average of 29°C (85°F), presenting the ideal escape for sun-seekers. Overall, January serves as a perfect introduction to San Diego’s inviting climate, balancing warmth and comfort while hinting at the hotter days to come.

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

The chart illustrates January 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.

January Precipitation in San Diego

In January, San Diego, Mexico, experiences a relatively mild start to the year with 30 mm (1.2 in) of precipitation over 4 days. Following January, the rainfall significantly drops in February to just 10 mm (0.4 in), marking one of the driest months. As spring approaches, March remains dry with only 8 mm (0.3 in) of rain, but moisture levels rise again by April, reaching 26 mm (1.0 in) over 5 days. The true onset of the rainy season occurs in June, where precipitation skyrockets to 192 mm (7.5 in), with rain nearly every other day. This trend continues through to September, the wettest month, with 128 mm (5.0 in), before tapering off in the cooler months of November and December. Overall, January marks a transition from the drier winter months to the more humid summer, setting the stage for the dramatic shifts that follow.

January Precipitation Trends in San Diego

The chart displays monthly precipitation patterns in San Diego, 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.
JanFebMarAprMayJunJulAugSepOctNovDec301082654192681031281295325
Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.
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January Humidity in San Diego

In January, San Diego, Mexico experiences a notably high humidity level of 85%, setting the tone for a month characterized by dampness. Following this peak, humidity slightly decreases in February to 80% and continues to decline through the spring months, reaching 69% in March and flattening out at about 64% in April and 63% in May. The trend shifts as the summer approaches, with humidity gradually rising again, peaking in the late months with 85% in September. This elevation continues, hitting 88% from October to December, suggesting that while January is humid, the trend reveals a cycle of fluctuating moisture, indicating a notable seasonal pattern in San Diego's climate.

January Average Humidity in San Diego

This chart illustrates the average monthly humidity levels in San Diego, with January's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how January's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec85%80%69%64%63%62%65%78%86%87%88%88%
Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in San Diego

In January, San Diego, Mexico, experiences a UV Index of 9, categorized as very high, with a burn time of just 15 minutes. As the months progress, the UV Index consistently escalates, peaking at 13 in the spring and summer months from March to July, indicating an extreme level of exposure with a burn time reducing to a mere 10 minutes. By August and September, the UV Index slightly tapers to 12, still maintaining an extreme classification. The year concludes with a decline in UV intensity, returning to a very high index of 9 in November and 8 in December. This trend highlights the importance of sun protection for those enjoying outdoor activities year-round. For more details on UV levels, visit San Diego UV Index.

Maximum UV Index Levels in San Diego for January

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

January Sunshine in San Diego

January ushers in 224 hours of sunshine in San Diego, Mexico, setting the stage for a delightful start to the year. As winter fades into spring, this sun-soaked paradise experiences a steady increase in daylight, peaking in May with an impressive 328 hours. The months that follow, from June to September, maintain a vibrant atmosphere with over 270 hours of shimmering sun each month, perfect for outdoor adventures. Though the sun starts to wane slightly in the fall and winter, with December seeing about 288 hours, San Diego remains a beacon of sunshine throughout the year, inviting visitors to bask in its warm embrace.

Monthly Sunshine Duration in San Diego: January Highlighted

The January sunshine duration represents the total number of hours San Diego experiences direct sunlight during the month of January, excluding cloudy or obstructed periods. This chart compares the sunshine duration of January with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec224h270h316h312h328h271h316h314h291h275h282h288h
Data source: San Diego January Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in San Diego During January

In San Diego, Mexico, the likelihood of sunny weather in January stands at a moderate 41%, setting the stage for the year ahead. As winter gives way to spring, the chances of sunshine steadily rise, peaking in March at 66% and then holding strong through April and November. Interestingly, January's likelihood mirrors conditions in May, suggesting a balance between cloud cover and clear skies. Following the sunniest months, a noticeable dip occurs in the summer, particularly in June with only 30% sunshine — a stark contrast that highlights the region’s seasonal variability. As the year progresses, the sun seems to make a robust return in the fall, reaffirming January’s role as a transitional month in San Diego's climate.

Percentage of Sunny Days in January in San Diego

The chart illustrates the percentage of sunny days in San Diego throughout the year, with January 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 January chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in San Diego in January

In San Diego, Mexico, January greets residents with 11 hours of daylight, a duration that remains steady into February. As spring approaches in March, the days begin to lengthen, with sunlight stretching to 12 hours. This trend of increasing daylight continues into April and May, ultimately peaking during the height of summer in June and July, where the sun graces the region with 13 hours daily. As autumn sets in, the daylight gradually recedes; August sees a drop to 12 hours, followed by a return to 11 hours in October and November, before narrowing down to 10 hours in December. This cyclical pattern highlights the vibrant transition of seasons in San Diego, ensuring that each month brings its own unique rhythm of light.

Average Daylight Hours in San Diego for January

The chart illustrates the variation in daylight duration in San Diego throughout the year, with January 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.

January Winds in San Diego

In January, the winds in San Diego, Mexico offer a gentle embrace with an average speed of 2.4 m/s (5 mph), making it one of the calmer months of the year. As the season progresses into February, a slight increase to 2.8 m/s (6 mph) is observed, signaling the subtle shift towards spring. The winds peak in March, April, and May at a steady 3.1 m/s (7 mph), providing a delightful breeze that enhances outdoor activities. However, as summer unfolds, the winds begin to taper off, dropping to 2.5 m/s (6 mph) in July, and settling at 2.4 m/s (5 mph) by the end of summer in August. The trend continues into the fall, where winds gradually decrease, reaching their lowest point in October at 1.7 m/s (4 mph). This cyclical pattern reflects the harmonious blend of seasonal changes, inviting both residents and visitors to enjoy San Diego’s mild and breezy January days.

Average January Wind Speed in San Diego

The chart displays monthly wind speed patterns in San Diego, with values for each month shown alongside January's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how January's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec2.4 m/s2.83.13.13.12.82.52.42.31.72.02.5
Data source: San Diego January wind data, generated using information from the Copernicus Climate Change Service.

How January 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 January'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.

January and February both feature warm temperatures, but February tends to be slightly milder overall. In January, the minimum temperature hovers around 11°C (52°F) with an average of 23°C (75°F) and peaks at a high of 38°C (101°F). In contrast, February starts off a bit cooler, with a minimum temperature of 10°C (50°F) and an average temperature of 25°C (78°F), capping out at 36°C (97°F). Additionally, precipitation is more frequent in January, receiving 30 mm (1.2 in) over 4 days compared to February's lighter 10 mm (0.4 in) over just 3 days. Humidity is also slightly lower in February at 80%, down from January’s 85%. For more details, check out San Diego weather in February.

In comparing the weather between January and March, it is clear that March offers slightly warmer conditions overall. January sees daily temperatures ranging from a minimum of 11°C (52°F) to a maximum of 38°C (101°F), with an average temperature of 23°C (75°F). This month also experiences higher humidity levels at 85%, along with 30 mm (1.2 in) of precipitation over four days. In contrast, March has a minimum temperature of 14°C (58°F) and an average of 27°C (80°F), peaking at 37°C (98°F). Notably, March is much drier, with only 8 mm (0.3 in) of precipitation over a single day and a lower humidity level of 69%. For more detailed insights, you can check San Diego weather in March.

In January, temperatures range from a minimum of 11°C (52°F) to a maximum of 38°C (101°F), with an average temperature of 23°C (75°F). The month experiences approximately 30 mm (1.2 in) of precipitation over 4 days, accompanied by high humidity levels at 85%. In contrast, April sees a slight increase in temperature, with a minimum of 16°C (61°F) and a maximum of 40°C (104°F), accompanied by an average temperature of 28°C (84°F). The precipitation is slightly lower at 26 mm (1.0 in) but occurs over 5 days, and humidity drops to a more comfortable 64%. For more detailed information on the weather in April, check San Diego weather in April.

In January, the weather typically experiences a minimum temperature of 11°C (52°F) and an average of 23°C (75°F), peaking at a maximum of 38°C (101°F). The month sees about 30 mm (1.2 in) of precipitation over 4 days, with humidity levels around 85%, making it feel quite muggy. In contrast, May is generally warmer with a minimum of 18°C (65°F), an average of 29°C (85°F), and a maximum temperature of 39°C (102°F). Precipitation increases to 54 mm (2.1 in) across 9 days, while humidity drops to a more comfortable 63%. For a more detailed look at the weather during this month, you can check San Diego weather in May.

When comparing January and June weather, notable differences in temperature and precipitation emerge. January typically sees milder temperatures, with a minimum of 11°C (52°F) and an average of 23°C (75°F), while June tends to be warmer, with a minimum of 22°C (72°F) and an average of 28°C (83°F). Despite both months reaching a maximum of 38°C (101°F), June experiences significantly more rainfall, totaling 192 mm (7.5 in) over 17 days compared to January's 30 mm (1.2 in) across just 4 days. Additionally, the humidity in January is higher at 85%, whereas June's humidity is lower at 62%. These factors contribute to a stark contrast in overall weather conditions between the two months. For more specific details, check out San Diego weather in June.

In comparing the weather between January and July, there are notable differences in temperature and precipitation. January typically experiences a comfortable range of temperatures, with a minimum of 11°C (52°F) and an average of 23°C (75°F), reaching up to a high of 38°C (101°F). It has relatively low precipitation at 30 mm (1.2 in) across only 4 days, coupled with high humidity at 85%. In contrast, July maintains warmer temperatures, with a minimum of 22°C (72°F) and an average of 28°C (83°F), peaking at nearly the same maximum of 38°C (100°F). However, July sees significantly more rainfall, totaling 68 mm (2.7 in) over 14 days, and lower humidity at 65%. These differences highlight the more humid and drier January versus the wetter and slightly milder July weather. For more details, check out San Diego weather in July.

When comparing the weather in January and August, notable differences emerge. January experiences milder temperatures, with minimums around 11°C (52°F) and an average of 23°C (75°F), contrasted with August, which has minimums of 21°C (71°F) and a higher average of 28°C (83°F). While January boasts lower precipitation levels at 30 mm (1.2 in) over just 4 days, August faces significantly more rainfall, totaling 103 mm (4.1 in) over 18 days. Additionally, January's humidity is higher at 85%, compared to August's 78%. For more specific insights into the August weather, visit San Diego weather in August.

When comparing the weather in January and September, notable differences emerge. January typically features milder temperatures, with a minimum of 11°C (52°F) and an average of 23°C (75°F), while September experiences warmer conditions, with a minimum of 22°C (71°F) and an average of 28°C (82°F). Additionally, January sees less precipitation, measuring about 30 mm (1.2 in) over just 4 days, whereas September receives significantly more rainfall at 128 mm (5.0 in) spread across 21 days. Interestingly, both months share the same humidity level of 85%, making September's warmth feel quite humid. For more detailed insights, you can check San Diego weather in September.

In January, temperatures range from a cooler minimum of 11°C (52°F) to a maximum of 38°C (101°F), with an average of 23°C (75°F). The month sees relatively low precipitation, averaging 30 mm (1.2 in) over just 4 days. Humidity levels are high, around 85%, contributing to a warm and tropical feel.

In contrast, October offers slightly warmer temperatures, with a minimum of 16°C (62°F) and an average of 27°C (80°F), peaking at 36°C (97°F). However, this month is significantly wetter, receiving 129 mm (5.1 in) of rainfall spread across 21 days, and maintaining a similar humidity level of 87%. For a detailed look at weather patterns during this time, check out San Diego weather in October.

January and November present contrasting weather patterns, with January experiencing a wider temperature range that includes minimums as low as 11°C (52°F) and maximums reaching up to 38°C (101°F). In comparison, November has milder temperatures, ranging from a minimum of 13°C (55°F) to a maximum of 34°C (93°F). Additionally, November sees increased rainfall, totaling 53 mm (2.1 in) over 11 days, compared to January's 30 mm (1.2 in) over just 4 days. Humidity levels are relatively similar, with January at 85% and November slightly higher at 88%. For a detailed look at the weather specifics in November, you can visit San Diego weather in November.

In January, temperatures range from a minimum of 11°C (52°F) to a maximum of 38°C (101°F), with an average temperature of 23°C (75°F). The month experiences 30 mm (1.2 in) of precipitation over about 4 days, with humidity levels around 85%. In contrast, December tends to be slightly cooler, with a minimum of 10°C (51°F), an average temperature of 24°C (75°F), and a maximum of 34°C (93°F). Precipitation is also lower in December, at 25 mm (1.0 in) over 5 days, with humidity being a touch higher at 88%. For a more detailed look at the weather in December, you can visit San Diego weather in December.

Compare San Diego's Climate with Cities Worldwide

Conclusion: What to Expect From January Weather in San Diego

In January, San Diego experiences a refreshing shift in weather compared to the warmer months, with a comfortable average temperature that encourages outdoor activities. While this month can bring occasional rain, with only a few precipitation days, the overall climate remains mild and inviting, characterized by higher humidity levels. As winter sets in, residents and visitors enjoy a break from the heat, making it a perfect time to explore the city’s scenic beaches and vibrant culture. For a comprehensive look at what to expect throughout the year, check out the detailed San Diego Climate information.