Last updated: February 24, 2025
January in San Diego offers a mild climate, characterized by a maximum temperature reaching a pleasant 25°C (77°F) and an average temperature of 14°C (58°F). The month typically sees minimum temperatures around 8°C (47°F). While the city enjoys a relatively dry winter, it experiences approximately 45 mm (1.8 in) of rainfall spread over 5 days, contributing to humidity levels around 72%. This combination makes January a comfortable time to explore the coastal landscapes and vibrant urban life of San Diego.
In January, San Diego greets the New Year with mild temperatures, showcasing a delightful range between a cool 8°C (47°F) in the early hours and a comfortable 25°C (77°F) by day. The average temperature hovers around 14°C (58°F), making it a serene month perfect for outdoor activities. As the month transitions into February, the scene remains similarly pleasant, with lows nudging just below 7°C (45°F) and highs edging up to 26°C (79°F). This mild climate continues into March, where temperatures slightly rise, yet the consistent 14°C (57°F) average invites residents and visitors alike to embrace the outdoors. The trend of gradually warming weather persists through spring, peaking in April at a high of 29°C (84°F). Overall, the January climate sets a charming tone for the months that follow, with each passing day hinting at the warmth and vibrancy that San Diego is known for.
January marks the beginning of the year in San Diego with moderate precipitation, totaling 45 mm (1.8 in) over five rainy days. This sets the stage for a wetter winter, as February sees a slight increase to 55 mm (2.2 in), continuing the trend before a drop in March, where rainfall falls to 38 mm (1.5 in) across eight days. As spring approaches, precipitation diminishes significantly, with April and May recording only 20 mm (0.8 in) and 16 mm (0.6 in) respectively, and June’s remarkable dryness only registering a mere 2 mm (0.1 in). This pattern of decreasing rainfall continues through the summer months, leading to nearly dry conditions. However, the cycle begins anew in the fall, with October and November experiencing modest returns of rain, ultimately culminating in December's wetter climate. Overall, January serves as a pivotal month, bridging the wet winter months and the dry summer ahead, highlighting San Diego's seasonal precipitation trends.
In January, San Diego experiences a moderate humidity level of 72%, marking the beginning of a gradual decline in moisture as the year progresses. By February, humidity peaks at 77%, but this is followed by a drop to 67% in March. As spring approaches, humidity continues to decrease, hitting a low of 46% by May and remaining quite stable through the summer months, with July and August both holding steady at 46% and 42% respectively. The trend shifts again in the fall; humidity starts to creep back up, reaching 66% by November and returning to 74% in December. This cyclical pattern highlights San Diego's transition from a humid winter to a pleasantly dry summer before the moisture rises again as the year wraps up.
In January, the UV Index in San Diego registers at 4, indicating a moderate exposure level with a burn time of around 30 minutes. This month sets the stage for a clear trend as the UV levels gradually rise; by February, the index jumps to 6, reflecting a high exposure category with a reduced burn time of 25 minutes. As spring approaches, the intensity continues to increase, peaking in the summer months when UV levels reach 11, categorized as extreme, allowing only 10 minutes of sun exposure before burns can occur. This stark transition highlights the necessity for sun protection as we move from the more forgiving UV conditions of winter to the harsher rays of summer. To stay informed on San Diego's UV forecasts throughout the year, check out San Diego UV Index.
UV Risk Categories
In San Diego, January marks the beginning of the year with a promising 195 hours of sunshine, setting the stage for a delightful winter. As the months progress, the sun shines brighter and longer, with February experiencing a notable increase to 243 hours. The trend continues into March and April, where the hours of sunshine soar to 299 and 325, respectively, heralding the arrival of spring. By May, the city basks in the glow of 361 hours, while June and July reach their peak with 366 and 376 hours of radiant sunshine. After the summer crescendo, the days begin to shorten, yet the golden rays remain generous, with August still holding high at 361 hours. As autumn settles in, sunshine hours gradually diminish to 318 in September and further down to 297 by October. November and December offer a cozy close to the year, each presenting 257 and 231 hours of sunlight, reminding us of the beauty in seasonal transitions. Overall, the trend in San Diego showcases a remarkable peak in sunshine during the summer months, making it a quintessential destination for sun lovers year-round.
In January, San Diego basks in the sun for about 63% of the days, making it one of the more delightful months for sunshine seekers. This percentage closely mirrors the chances of sunny weather in both February and March, indicating a consistent winter trend. Interestingly, as the year progresses, the likelihood of sunny days shifts, with April witnessing a dip to 50%, suggesting a transitional phase. The weather warms up again towards the summer months, but the sunniest months—like October—see a slight increase to 64%. Overall, January stands out in its winter glory, providing a refreshing escape for those looking to soak up the California sun.
In San Diego, January brings a modest 10 hours of daylight, setting the stage for a gradual increase as winter transitions into spring. By February, the days elongate to 11 hours, and this upward trend continues into March with a full 12 hours of sunlight. As the days warm up, April and May see consistent daylight at 13 hours, before peaking in June and July with a generous 14 hours of sunlight. This abundant bright spell then begins to taper off, with August seeing a slight decrease back to 13 hours, followed by a gradual decline through September and October. By November, daylight retreats once again to 10 hours, completing the cycle as December mirrors January's shorter days. This rhythm of daylight emphasizes San Diego's seasonal shifts, offering residents and visitors alike a vibrant tapestry of light throughout the year.
In January, San Diego greets the year with a gentle breeze, featuring an average wind speed of 3.0 m/s (7 mph). This sets a vibrant tone for the month as the winds gradually shift in the following weeks. Interestingly, February experiences a slight dip, dropping to 2.7 m/s (6 mph), which hints at a calmer atmosphere. As we move into March, the winds pick up again, reaching 3.4 m/s (8 mph)—the most vigorous gusts of the first quarter. The progression into spring shows a noticeable steadiness in the wind speeds, ranging between 3.1 m/s and 3.4 m/s from March to June, creating a pleasant, consistent breeze ideal for outdoor activities. Ultimately, the winds soften a bit into the latter months, with November registering the year’s lowest at 2.4 m/s (5 mph), heralding a tranquil end to the season. Overall, January's winds set a dynamic yet calm precedent, encapsulating the mild charm that characterizes San Diego's climate throughout the year.
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.
In comparing the weather of January and February, both months exhibit similar average temperatures, with January showcasing a minimum of 8°C (47°F) and a maximum of 25°C (77°F), while February sees slightly lower minimums at 7°C (45°F) and a maximum temperature increase to 26°C (79°F). Precipitation levels are also somewhat higher in February, with 55 mm (2.2 in) over 6 days, compared to January’s 45 mm (1.8 in) over 5 days. Additionally, February typically experiences a higher humidity level of 77% compared to January's 72%. For more detailed information on February's climate, you can check San Diego weather in February.
In comparing the weather between January and March, we see a slight increase in average temperatures, with January averaging 14°C (58°F) and March reaching 15°C (59°F). While both months have the same minimum temperature of 8°C (47°F), March boasts a slightly higher maximum temperature of 26°C (80°F) compared to January's 25°C (77°F). Precipitation is relatively close, with January receiving 45 mm (1.8 in) over 5 days, while March has 38 mm (1.5 in) but sees rainfall over a greater number of days at 8. Additionally, humidity is slightly lower in March at 67%, compared to January's 72%. For more specific details, you can check out the link on San Diego weather in March.
January and April exhibit distinct weather patterns that highlight the transition between winter and spring. In January, temperatures range from a minimum of 8°C (47°F) to a maximum of 25°C (77°F), with an average of 14°C (58°F). The month sees approximately 45 mm (1.8 inches) of precipitation over five days, contributing to a higher humidity level of 72%. In contrast, April experiences milder temperatures, with a minimum of 11°C (53°F) and a maximum of 29°C (84°F), averaging 16°C (61°F). Precipitation drops significantly to just 20 mm (0.8 inches) over two days, and the humidity decreases to 56%. This transformation from January to April reflects the shift toward warmer and drier conditions. For more detailed insights, check out San Diego weather in April.
In January, the weather in San Diego is characterized by a mild temperature range, with minimums around 8°C (47°F) and averages reaching 14°C (58°F). The maximum temperature can rise to 25°C (77°F), and the month generally sees about 45 mm (1.8 in) of precipitation over approximately 5 days, with a humidity level of 72%.
In contrast, May experiences slightly warmer temperatures, with minimums at 12°C (54°F) and an average of 17°C (62°F), while still peaking at 25°C (78°F). Precipitation is considerably lower at 16 mm (0.6 in) over about 4 days, and the humidity drops to a more comfortable 46%. For more detailed information, you can check San Diego weather in May.
In January, the weather features a minimum temperature of 8°C (47°F) and an average of 14°C (58°F), with a maximum reaching 25°C (77°F). This month experiences moderate precipitation of 45 mm (1.8 in) spread over approximately 5 days, accompanied by higher humidity levels of around 72%. In contrast, June sees warmer temperatures, with a minimum of 14°C (58°F), an average of 18°C (65°F), and maximum temperatures peaking at 29°C (84°F). Notably, June is much drier, with only 2 mm (0.1 in) of precipitation over no rainy days and significantly lower humidity at 48%. For more information on the specific weather patterns and details in June, you can visit San Diego weather in June.
In January, the weather is notably cooler with temperatures ranging from a minimum of 8°C (47°F) to a maximum of 25°C (77°F), and an average of 14°C (58°F). This month also experiences higher humidity at 72% and receives about 45 mm (1.8 in) of precipitation over five days. In contrast, July offers a warmer climate with temperatures ranging from a minimum of 16°C (62°F) to a maximum of 29°C (85°F), with an average of 21°C (69°F). Additionally, it is much drier in July, receiving only 1 mm (0.1 in) of precipitation and boasting zero rainy days, accompanied by lower humidity at 46%. For more detailed information, check out San Diego weather in July.
In January, the weather in San Diego features a minimum temperature of 8°C (47°F) and averages around 14°C (58°F), with maximums reaching up to 25°C (77°F). The month experiences a moderate level of precipitation, with 45 mm (1.8 in) of rain spread over approximately 5 days, contributing to a humidity level of 72%. In contrast, August offers a significantly warmer climate, with minimum temperatures around 17°C (63°F) and averages of 21°C (71°F), peaking at 29°C (84°F). Remarkably, August has minimal precipitation, measuring only 1 mm (0.0 in) across the entire month, and enjoys a lower humidity of 42%. For more details on the weather in August, you can visit San Diego weather in August.
In January, the weather is significantly cooler, with temperatures ranging from a minimum of 8°C (47°F) to a maximum of 25°C (77°F), and an average of 14°C (58°F). This month experiences about 45 mm (1.8 in) of precipitation over approximately five days, accompanied by higher humidity levels at 72%. In contrast, September is much warmer, with temperatures ranging from a minimum of 17°C (62°F) to a maximum of 31°C (88°F) and an average of 21°C (70°F). Precipitation is minimal in September, with only 3 mm (0.1 in) recorded, and no rainy days, making it a drier month with lower humidity at 52%. For more details, check out San Diego weather in September.
In January, the weather tends to be cooler with minimum temperatures around 8°C (47°F) and average highs reaching up to 25°C (77°F), accompanied by 45 mm (1.8 in) of precipitation over approximately 5 days. The humidity is relatively high at 72%, creating a damp feel. In contrast, October boasts warmer temperatures, starting at 13°C (55°F) and peaking at a maximum of 32°C (90°F) on average. With only 13 mm (0.5 in) of precipitation over just 2 days, the humidity drops to 58%, making it a much drier and more comfortable month. For more detailed insights, you can check out San Diego weather in October.
In comparing the weather between January and November, we see a notable difference in temperatures and precipitation. January experiences a wider temperature range, with minimums around 8°C (47°F) and maximums reaching 25°C (77°F), while November is slightly warmer on average, with minimums of 10°C (51°F) and maximums peaking at 27°C (81°F). Precipitation levels are also lower in November, receiving only 24 mm (0.9 in) over just 2 days, compared to January's 45 mm (1.8 in) across 5 days. Additionally, November has lower humidity at 66%, compared to January's 72%. For more detailed information, you can check San Diego weather in November.
In comparing the weather of January and December, we find that both months feature similar minimum temperatures, averaging around 8°C (47°F). However, January tends to be slightly warmer overall with an average temperature of 14°C (58°F) compared to December's 15°C (59°F). Both months experience a maximum temperature close to 25°C (77°F), but precipitation differs notably; December sees more rainfall at 60 mm (2.4 in) versus January's 45 mm (1.8 in), both occurring over five days. Additionally, humidity levels remain fairly consistent, with January at 72% and December slightly higher at 74%. For more detailed insights on December weather, you can visit San Diego weather in December.
January in San Diego presents a refreshing contrast to the warmer, sunnier months that the city is famous for. With milder temperatures and increased humidity, this month often invites a cozy atmosphere, making it perfect for exploring the city's scenic beauty without the sweltering heat. Although it experiences more precipitation than some of its drier summer months, the rain typically comes and goes quickly, allowing for plenty of enjoyable outdoor activities in between. For those looking to embrace a different side of San Diego, January's cool yet pleasant weather provides a unique blend of experiences. Discover more about how San Diego's climate evolves throughout the year at San Diego Climate.