Last updated: February 24, 2025
January in Pasadena, United States, showcases a dynamic climate that blends mild temperatures with occasional rainfall. The maximum temperature can reach a pleasant 29°C (84°F), while the average hovers around 12°C (53°F), providing a comfortable atmosphere. However, nighttime can be brisk, with minimum temperatures dipping to 0°C (32°F). This month sees about 75 mm (3.0 in) of precipitation, typically spread over 5 days, contributing to a relative humidity level of 78% that adds a refreshing edge to the crisp winter air. Overall, January offers a unique blend of warmth and chill, making it an intriguing time to experience Pasadena's diverse weather.
In Pasadena, January greets residents with a cool start to the year, showcasing a temperature range that can fluctuate significantly. Minimums hover around 0°C (32°F), while the daily average nudges up to a comfortable 12°C (53°F). As the month progresses, daytime highs can reach an impressive 29°C (84°F), hinting at the warmth that will soon define the region. This blend of cool nights and pleasantly warm days sets the stage for a gradual transition into the slightly warmer days of February. The consistent temperatures observed in January serve as a gentle reminder that winter in Pasadena, while cooler than the rest of the year, remains mild and inviting for outdoor activities.
In January, Pasadena experiences a notable start to the year with 75 mm (3.0 in) of precipitation spread across an average of 5 days. This marks the wettest month at the outset, setting a contrast to the drier conditions that evolve as the year progresses. Following January, February sees a slight decrease in rainfall at 65 mm (2.6 in) over 6 days, hinting at the transition towards a drier spring. As the months unfold, March brings an increase to 85 mm (3.4 in) but with more precipitation days, while April and May drop significantly, revealing a stark shift with just 22 mm (0.9 in) and 16 mm (0.6 in) respectively. Notably, the summer months of June through August virtually devoid of rainfall, each reporting only 1 mm to 2 mm across the entire span, suggest a season characterized by dry heat. This pattern culminates in the year’s conclusion, where December again brings moisture back with 77 mm (3.1 in), reminiscent of January's soggy start, illustrating Pasadena's distinct seasonal contrasts from wet beginnings to arid summers.
In Pasadena, January ushers in a humid ambiance with an average humidity level of 78%, setting a moist tone for the start of the year. This figure is slightly below February's higher 82%, yet remains above the subsequent month's drop to 75% in March. As spring approaches, humidity gradually decreases, reaching its lowest point of 46% in July, coinciding with the warmest summer months. August sees a further dip to 39%, making for pleasantly dry conditions. However, as autumn sets in, humidity begins to rise again, peaking at 76% in December. Overall, Pasadena experiences a dynamic humidity cycle, reflecting a shift from moist winter months to the arid essence of summer, before welcoming the return of humidity in the fall.
In January, Pasadena experiences a moderate UV Index of 4, with a burn time of 30 minutes under the sun. As the month progresses into February, the UV Index rises to 6, indicating a high exposure category and a slightly reduced burn time of 25 minutes. This upward trend continues into March and April, where the index reaches 8 and 10, respectively, elevating the exposure risk to very high and shortening burn times to 15 minutes. As summer approaches, the UV Index peaks in May and June at a striking 11, categorized as extreme, with an even faster burn time of just 10 minutes. Notably, the intensity remains high throughout July and August before tapering off in September. The cycle of UV exposure returns to moderate levels in November and December, highlighting significant seasonal variation. For a detailed look at the UV Index trends throughout the year, visit Pasadena UV Index.
UV Risk Categories
Pasadena boasts a delightful evolution of sunlight hours throughout the year, with January kicking off with a respectable 185 hours of sunshine. As winter gives way to spring, the sun becomes increasingly generous, peaking in May with an impressive 356 hours. The city enjoys its sunniest months in the height of summer, with July basking in 381 hours of glorious sunlight. As the seasons shift toward fall, sunshine gradually diminishes, with October and November seeing a steady decline to 292 and 255 hours respectively. December wraps up the year with a cozy 222 hours, reminding residents of the warmth to come in the new year. Overall, the trend outlines a classic California narrative—sunshine-filled days characterized by gradual increases as the seasons transition, ultimately leading to a vibrant summer glow.
In Pasadena, January ushers in a 63% likelihood of sunny weather, setting a solid tone for the year ahead. As the months progress into spring and summer, the chances of sunshine only increase, peaking at 85% in September. Notably, February and May offer encouraging sunny predictions of 71% and 72% respectively, indicating a trend where the winter months gradually give way to clearer skies. However, by December, there's a notable decline to 51%, reminding us that the year does close with a touch of overcast. Overall, the sunny disposition of Pasadena shines brightest during the mid-year, while January serves as a promising start to a year filled with sunshine.
In Pasadena, the daylight duration gradually shifts throughout the year, starting with a consistent 10 hours in both January and February. As spring approaches, daylight begins to extend, reaching 11 hours in March and blossoming to 13 hours by April and May. The peak comes in the summer months, where June and July enjoy the longest days at 14 hours. However, as the year progresses into late summer and fall, daylight gradually diminishes, with August at 13 hours and decreasing to 12 hours in September. This trend continues, bringing daylight down to 11 hours in October and dropping to 10 hours in November, before settling at 9 hours in the shorter days of December. Through this cycle, Pasadena experiences a dynamic rhythm of light that beautifully marks the transition of the seasons.
In Pasadena, January brings a gentle breeze with an average wind speed of 2.4 m/s (5 mph), making it one of the windiest months of the year. As the season progresses into February and March, the winds slightly decrease, stabilizing at 2.2 m/s and 2.1 m/s, respectively. This gradual decline continues through spring and into summer, where wind speeds plateau at 1.8 m/s (4 mph) from June to August. Interestingly, as autumn approaches, the winds show a slight revival in October and November, increasing to 2.0 m/s, before settling back into a calm December. This trend reveals a consistent pattern: mild beginnings that taper off into the warmer months, only to gently lift again as the year winds down.
The weather in Pasadena 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 Pasadena and find detailed weather information for every month.
In January, temperatures in Pasadena range from a minimum of 0°C (32°F) to a maximum of 29°C (84°F), with an average temperature of 12°C (53°F). The month sees about 75 mm (3.0 in) of precipitation over approximately 5 days, and humidity levels hover around 78%. In contrast, February shares a similar temperature profile, with a minimum of 0°C (31°F), an average of 12°C (54°F), and a maximum of 28°C (83°F). However, February experiences slightly less rainfall, totaling 65 mm (2.6 in) over 6 days, and shows a marginal increase in humidity at 82%. For more detailed insights, check out Pasadena weather in February.
In comparing the weather between January and March, we see similar temperature ranges, with both months experiencing mild averages. January has a minimum temperature of 0°C (32°F) and an average of 12°C (53°F), while March starts with a slightly higher minimum of 1°C (34°F) and averages around 13°C (56°F). The maximum temperatures for both months are comparable, reaching 29°C (84°F) in January and 30°C (86°F) in March. Precipitation is a bit higher in March, totaling 85 mm (3.4 in) over 10 days, compared to January's 75 mm (3.0 in) over just 5 days. Interestingly, March has slightly lower humidity at 75% compared to January's 78%. For more detailed insights on March weather, check out Pasadena weather in March.
In January, the weather in Pasadena is characterized by a cool range of temperatures, with a minimum of 0°C (32°F) and a maximum reaching up to 29°C (84°F). The average temperature hovers around 12°C (53°F), accompanied by relatively high humidity at 78%. Moreover, January sees about 75 mm (3.0 in) of precipitation spread over 5 days, indicating a wetter start to the year.
In contrast, April presents a noticeable shift in climate. The minimum temperature rises to 6°C (43°F), while the maximum soars to 34°C (94°F), giving an average of 17°C (62°F). Precipitation drops significantly to just 22 mm (0.9 in) over 2 days, and humidity decreases to 68%, making April generally drier and warmer than January. For more detailed insights on April weather, visit Pasadena weather in April.
In Pasadena, January offers a notable temperature range featuring a minimum of 0°C (32°F), an average of 12°C (53°F), and a maximum of 29°C (84°F). The month experiences fairly high humidity levels at 78% and sees approximately 75 mm (3.0 in) of rainfall over about 5 days. In contrast, May brings warmer temperatures with a minimum of 6°C (43°F), an average of 18°C (64°F), and a maximum reaching 34°C (94°F). Precipitation drops significantly to just 16 mm (0.6 in) on about 3 days, alongside reduced humidity at 57%. For more insights on the weather in Pasadena during this month, visit Pasadena weather in May.
In January, the weather tends to be cooler with temperatures ranging from a minimum of 0°C (32°F) to a maximum of 29°C (84°F), and an average temperature of 12°C (53°F). This month experiences 75 mm (3.0 in) of rainfall over approximately 5 days, contributing to a higher humidity level of 78%. In contrast, June brings significantly warmer temperatures, with a minimum of 11°C (51°F), an average of 22°C (71°F), and soaring highs that can reach up to 40°C (105°F). Rainfall is almost nonexistent during this month, with just 1 mm (0.1 in) and no recorded rainy days, resulting in a much lower humidity of 52%. For more details, check out Pasadena weather in June.
January and July present strikingly different weather patterns. In January, temperatures range from a chilly minimum of 0°C (32°F) to a mild maximum of 29°C (84°F), accompanied by a notable average of 12°C (53°F). The month sees a moderate level of precipitation at 75 mm (3.0 in) spread over 5 days, contributing to a humid environment with 78% humidity. In stark contrast, July boasts significantly warmer temperatures, with a minimum of 13°C (57°F) and a scorching maximum of 43°C (109°F), averaging a comfortable 25°C (77°F). Moreover, July is much drier, experiencing only 2 mm (0.1 in) of precipitation over the entire month, and enjoys low humidity levels at 46%. For more specifics about July's climate, you can check Pasadena weather in July.
January and August present striking contrasts in weather. In January, temperatures range from a chilly 0°C (32°F) at night to a comfortable average of 12°C (53°F) during the day, with highs reaching up to 29°C (84°F). This month also experiences significant rainfall, with around 75 mm (3.0 in) of precipitation over approximately five days and a high humidity level of 78%. In contrast, August boasts much warmer temperatures, with a minimum of 15°C (59°F) and an average of 25°C (78°F), peaking at a scorching 40°C (105°F). Remarkably, precipitation during this month is minimal, totaling only 2 mm (0.1 in) and occurring on no days, along with a much lower humidity of 39%. For more details about the weather in August, you can check Pasadena weather in August.
In January, the weather is relatively cool, with average temperatures ranging from a minimum of 0°C (32°F) to a maximum of 29°C (84°F) and experiencing about 75 mm (3.0 in) of precipitation over 5 days, contributing to a high humidity level of 78%. In contrast, September brings much warmer conditions, with an average temperature of 23°C (74°F), a minimum of 10°C (51°F), and extreme highs reaching up to 44°C (112°F). Additionally, September is quite dry, with only 4 mm (0.1 in) of precipitation across the month and no rainy days, resulting in a considerably lower humidity level of 48%. For more detailed information, you can check Pasadena weather in September.
January and October in Pasadena exhibit quite different weather patterns. In January, temperatures range from a chilly 0°C (32°F) at night to a warm 29°C (84°F) during the day, with an average temperature of 12°C (53°F). This month experiences a higher humidity level of 78% and a total precipitation of 75 mm (3.0 in) over approximately 5 days. In contrast, October features milder nights with a minimum of 6°C (44°F) and significantly warmer days, reaching up to a scorching 38°C (101°F), with an average of 20°C (68°F). Rainfall drops dramatically to just 9 mm (0.4 in) over 1 day, and humidity decreases to 59%. For more information on October weather, you can visit Pasadena weather in October.
In January, temperatures in Pasadena range from a chilly 0°C (32°F) at night to a warm 29°C (84°F) during the day, with an average of 12°C (53°F). The month typically experiences about 75 mm (3.0 inches) of precipitation over five days, leading to a relatively humid atmosphere at 78%. In contrast, November offers milder weather with minimum temperatures of 2°C (37°F) and maximums reaching 31°C (89°F), averaging around 16°C (61°F). Additionally, November is considerably drier, receiving only 24 mm (0.9 inches) of rain over just two days and showcasing lower humidity levels at 72%. For a more detailed look at what to expect during this time, check out Pasadena weather in November.
January and December exhibit quite similar weather patterns, with average temperatures hovering around 12°C (53°F). January sees a slightly wider range, with minimum temperatures dropping to 0°C (32°F) and maximums reaching 29°C (84°F), compared to December's minimum of 1°C (33°F) and maximum of 27°C (81°F). Precipitation levels are also close, with January receiving 75 mm (3.0 in) and December 77 mm (3.1 in), both across five days. Interestingly, January has a marginally higher humidity level at 78%, while December remains slightly lower at 76%. For more detailed information, check out Pasadena weather in December.
In January, Pasadena experiences a refreshing contrast to its typically warmer months, with cooler temperatures that create a mild, comfortable atmosphere. While the days are pleasantly crisp, the average chill invites a cozy ambiance, making it a perfect time for outdoor activities without the sweltering heat. Additionally, January brings in a modest amount of rain, refreshing the landscape and contributing to the city's lush scenery, all while maintaining relatively high humidity levels. This unique blend of climate characteristics makes January distinctly enjoyable, setting it apart from the more arid and hotter summer months. For a deeper insight into Pasadena's diverse weather patterns, visit Pasadena Climate.