Last updated: April 22, 2025
In September, San Diego, Mexico, experiences a warm and humid climate, with maximum temperatures soaring to 37°C (98°F) and an average of 28°C (82°F). While the heat can be intense, the region also faces significant precipitation, with 128 mm (5.0 in) of rainfall recorded over 21 days. Coupled with an humidity level of 85%, this combination creates a tropical atmosphere that is both lush and invigorating. Visitors and locals alike should prepare for a mix of sun and showers as they enjoy this vibrant coastal destination during the month.
As September arrives in San Diego, Mexico, the climate remains pleasantly warm, with average temperatures hovering around 28°C (82°F). The month typically sees a minimum of 22°C (71°F) and a maximum reaching 37°C (98°F). This steady warmth reflects a trend of gradually increasing temperatures from the cooler months earlier in the year, peaking in the summer. September's climate offers a delightful blend of warmth without the extreme highs experienced in late summer, making it an ideal time for visitors to enjoy the region's outdoor activities and beautiful beaches. As the month progresses, slight dips in temperature signal the approach of autumn while retaining a sunny, inviting atmosphere.
In September, San Diego, Mexico experiences a significant increase in precipitation, receiving 128 mm (5.0 in) over 21 days—the month’s rainfall is among the highest recorded throughout the year. This marks a noticeable uptick from the preceding months, with rain beginning to pour in earnest after the summer. Both August and June boast considerable rainfall, but September stands out as rain patterns peak, preparing the region for the milder, more stabilized weather that follows in October. The extended duration of rainfall this month hints at a transition period where summer's heat gives way to more temperate conditions, illustrating nature's rhythm amidst the vibrant landscape.
In September, San Diego, Mexico, experiences a notable spike in humidity, returning to 85%, which mirrors the levels seen at the beginning of the year. This month serves as a transitional period, as the sultry summer months of July and August, with humidities of 65% and 78% respectively, give way to the wetter months ahead. As the year progresses towards October and November, humidity levels continue to rise, peaking at 88%. This trend highlights a significant seasonal shift, where the warmth of September often brings a palpable mugginess, setting the stage for the cooler and more humid conditions of fall and winter in San Diego.
In September, San Diego experiences a UV Index of 12, maintaining its designation as extreme exposure, similar to the month prior. With a burn time of only 10 minutes, this indicates that sun protection is critical during this time. As summer transitions to fall, the UV levels remain high, showing a consistency in the sun's intensity that has persisted since June. Visitors and residents alike should be vigilant, remembering that while the UV Index dips slightly in October, it still reflects extreme exposure levels. For more insights and details, check out the comprehensive guide on the San Diego UV Index.
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As summer wanes and September arrives in San Diego, Mexico, the city embraces a delightful blend of warmth and sunshine, boasting 291 hours of radiant sunlight. This marks a subtle decline from the sun-drenched peaks of May and June, where the hours soared above 320, yet it still offers a robust display of golden rays. The trend shows that San Diego enjoys its sunniest days through the late spring and summer months, tapering off as autumn approaches. Thankfully, September’s glow remains vibrant, inviting locals and visitors alike to savor the lingering warmth before the cool October breeze sets in. With an average of 275 sunshine hours in October, the transition into fall promises a gentle embrace, keeping the spirit of summer alive just a bit longer.
As the summer fades, September in San Diego, Mexico, often sees a dip in sunny skies, with a 32% chance of sunshine. This marks a significant decline compared to the sunnier months preceding it; while August enjoys a more robust 50% chance, September's weather begins to hint at the coming fall. Interestingly, the trend reveals that September typically falls among the lower end of the yearly spectrum for sun, trailing behind the more cheerful months of March and April, which boast chances of 66% and 57%, respectively. As the allure of sun-soaked days wanes, visitors can anticipate a transition into crisper temps and a more varied weather pattern as the month progresses.
As September arrives in San Diego, Mexico, the city enjoys a delightful 12 hours of daylight, marking the transition into the autumn season. This month maintains the same daylight duration as August, representing a shift from the peak summer brightness of 13 hours experienced in May through July. Following September, daylight begins to wane as October brings a return to 11 hours. Overall, the progression from winter's shorter days to the summer’s long stretches of sunshine highlights an intriguing seasonal rhythm, where daylight duration slowly fluctuates but remains relatively stable during the summer months, before gently tapering off into the latter part of the year.
As summer transitions to autumn, September in San Diego, Mexico, brings a gentle breeze with an average wind speed of 2.3 m/s (5 mph). This slight decline continues the trend observed over the warmer months, as wind speeds gradually decreased from the peak in March through May, where they consistently hovered around 3.1 m/s (7 mph). Compared to the earlier months, September's winds are softer, reflecting a shift towards more tranquil conditions as the heavy heat of summer starts to wane. With the approach of October, one can expect these serene breezes to continue, setting the stage for the cooler months ahead, where wind speeds dip further to an average of 1.7 m/s (4 mph). This gradual ebb of wind creates an inviting atmosphere, perfect for enjoying the beautiful coastal landscapes of San Diego.
The weather in San Diego changes throughout the year, offering a unique experience in each season. Below is a month-by-month comparison of September'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 September, the weather is characterized by warmer temperatures, with a minimum of 22°C (71°F) and an average of 28°C (82°F), reaching a maximum of 37°C (98°F). The month sees significant precipitation, with 128 mm (5.0 in) falling over 21 days, contributing to high humidity levels of 85%. In contrast, January offers a cooler climate, with a minimum temperature of 11°C (52°F) and an average of 23°C (75°F); though it can reach a high of 38°C (101°F). Precipitation drops significantly to just 30 mm (1.2 in) across only 4 days, yet humidity remains at 85%. For a detailed overview of weather during this month, check out San Diego weather in January.
September weather is typically warmer and more humid than February, with temperatures ranging from a minimum of 22°C (71°F) to a maximum of 37°C (98°F) and an average of 28°C (82°F). This month also sees a significant amount of rainfall, averaging 128 mm (5.0 in) over 21 days, contributing to the high humidity of 85%. In contrast, February features a cooler climate, with minimum temperatures dropping to 10°C (50°F) and maximums reaching 36°C (97°F), while averaging 25°C (78°F). Precipitation is minimal during this month, recorded at just 10 mm (0.4 in) over only 3 days, and humidity is slightly lower at 80%. For more details, you can check out the weather specifics at San Diego weather in February.
When comparing the weather of September and March, notable differences emerge. September typically experiences higher temperatures with a minimum of 22°C (71°F) and an average of 28°C (82°F), while March offers cooler conditions, starting at a minimum of 14°C (58°F) and averaging at 27°C (80°F). Interestingly, both months can reach a maximum temperature of 37°C (98°F); however, September is characterized by significantly higher precipitation with 128 mm (5.0 in) over 21 days, whereas March enjoys a much drier climate, receiving only 8 mm (0.3 in) in just one day. Additionally, September's humidity level sits at a higher 85%, in contrast to March's more comfortable 69%. For more detailed insights on conditions in March, check out San Diego weather in March.
September and April present contrasting weather patterns. In September, temperatures range from a minimum of 22°C (71°F) to a scorching maximum of 37°C (98°F), with an average of 28°C (82°F). The month is marked by high humidity at 85% and considerable rainfall, totaling 128 mm (5.0 in) over 21 days. In contrast, April enjoys slightly cooler temperatures with a minimum of 16°C (61°F) and a maximum of 40°C (104°F), maintaining the same average of 28°C (84°F). However, it features significantly less rainfall at just 26 mm (1.0 in) across 5 days and lower humidity at 64%. For more insights, check San Diego weather in April.
When comparing the weather in September and May, a few notable differences emerge. September tends to be more humid, with an average humidity of 85%, making the warm temperatures feel even warmer, with highs reaching up to 37°C (98°F). In contrast, May enjoys slightly lower humidity at 63%, with temperatures peaking at 39°C (102°F), creating a more comfortable atmosphere. Additionally, September experiences significantly more rainfall, totaling 128 mm (5.0 in) over 21 days, whereas May sees only 54 mm (2.1 in) over just 9 days. For a detailed look at weather conditions, you can check San Diego weather in May.
In comparing the weather of September and June, we can see some notable differences. Both months feature similar minimum temperatures, hovering around 22°C (71°F to 72°F), and average temperatures are closely aligned at 28°C (82°F to 83°F). However, June tends to be slightly warmer at its maximum, reaching up to 38°C (101°F) compared to September’s peak of 37°C (98°F).
Precipitation levels also vary significantly; June receives more rainfall, totaling 192 mm (7.5 in) over 17 days, while September sees 128 mm (5.0 in) across a longer stretch of 21 days. Interestingly, humidity is higher in September at 85%, compared to June's 62%, which suggests that while June may feel hotter, September's weather is more humid and prone to rainfall. For more insights on June weather, you can visit San Diego weather in June.
In comparing the weather between September and July, we find that both months exhibit warm temperatures, with average temperatures in September slightly lower at 28°C (82°F) compared to July's average of 28°C (83°F). However, July can reach a higher maximum temperature of 38°C (100°F) versus September's peak of 37°C (98°F). Notably, September experiences significantly more rainfall, with 128 mm (5.0 in) over 21 days, compared to July's 68 mm (2.7 in) over just 14 days. Additionally, September's humidity level is higher at 85%, while July has a more comfortable 65%. For a detailed overview, you can check the San Diego weather in July.
In comparing the weather of September and August, we see that both months feature similar average temperatures, with September experiencing a minimum of 22°C (71°F) and an average of 28°C (82°F), while August has a minimum of 21°C (71°F) and an average of 28°C (83°F). However, September tends to be slightly wetter with 128 mm (5.0 in) of precipitation over 21 days, compared to August's 103 mm (4.1 in) over 18 days. Additionally, September has a higher humidity level at 85%, while August's humidity is recorded at 78%. For more insights on August weather, you can visit San Diego weather in August.
In September, the weather is generally hotter, with average temperatures reaching 28°C (82°F) and maximums soaring up to 37°C (98°F). The month experiences a high humidity level of 85% and similar precipitation patterns, totaling 128 mm (5.0 in) over 21 days. However, as October arrives, temperatures cool slightly, with a minimum of 16°C (62°F) and an average of 27°C (80°F), while maximums still hit 36°C (97°F). The precipitation remains comparable at 129 mm (5.1 in) over the same number of rainy days, and humidity slightly increases to 87%. For more detailed insights on October weather, you can visit San Diego weather in October.
September and November exhibit contrasting weather patterns. In September, temperatures range significantly, with a minimum of 22°C (71°F), an average of 28°C (82°F), and a maximum reaching up to 37°C (98°F). This month is marked by higher precipitation, averaging 128 mm (5.0 in) over 21 days and maintaining a high humidity level of 85%. In contrast, November offers a cooler climate, with temperatures dipping to a minimum of 13°C (55°F) and averaging 25°C (77°F), while the maximum is a milder 34°C (93°F). Rainfall decreases substantially to 53 mm (2.1 in) across only 11 days, paired with slightly elevated humidity at 88%. For more insights on the November weather, you can check this link: San Diego weather in November.
September weather is characterized by warmer temperatures, with a minimum of 22°C (71°F) and an average of 28°C (82°F), reaching up to a maximum of 37°C (98°F). This month also sees significant rainfall, with 128 mm (5.0 in) over 21 days and high humidity levels at 85%. In contrast, December brings much cooler temperatures, featuring a minimum of 10°C (51°F) and an average of 24°C (75°F), maxing out at 34°C (93°F). The precipitation decreases dramatically to just 25 mm (1.0 in) over only 5 days, with humidity slightly higher at 88%. For more details, check out San Diego weather in December.
As September rolls in, San Diego experiences a noticeable shift in weather compared to the preceding summer months. This transitional period brings warmer temperatures, with higher humidity levels that can make the heat feel more intense. While the summer days bask in consistent sunshine, September often introduces a mix of clouds and increased rainfall, seen in its frequent showers and higher precipitation days. Despite the lingering warmth, the added moisture contributes to the vibrant atmospheres that uniquely define this month. For a deeper dive into what the seasons hold for this beautiful city, check out San Diego Climate.