Last updated: February 24, 2025
In September, Carlsbad experiences a delightful mix of warm temperatures and refreshing breezes. With a maximum of 38°C (101°F) and an average of 25°C (78°F), the weather invites outdoor activities and exploration. The minimum temperature drops to a cool 8°C (47°F), providing a perfect contrast for evening strolls. Although the month sees 29 mm (1.1 in) of rain over 6 days, the overall humidity of 71% ensures a comfortable atmosphere. This combination of warmth and occasional showers creates an ideal setting for enjoying everything Carlsbad has to offer in early autumn.
September in Carlsbad ushers in a gentle transition from the sweltering summer months to the cooler embrace of autumn. With temperatures ranging from a minimum of 8°C (47°F) at night to a maximum of 38°C (101°F) during the day, the average temperature settles comfortably at around 25°C (78°F). This drop from the relentless heat of July and August is welcomed by many, as it marks a perfect time for outdoor activities amidst pleasantly warm days and cooler nights. As the month progresses, you can expect a delightful mix of sunshine and the onset of fall, setting a picturesque backdrop for this charming coastal city.
In September, Carlsbad experiences a significant uptick in precipitation, receiving 29 mm (1.1 in) of rain over six days. This marks a continuation of the wet summer trend, following August's peak of 34 mm (1.3 in), indicating a transition into the fall months. As the skies open up, the increase in rainfall can be seen as a refreshing respite after the warmer summer, setting the stage for a gradual cool-down. Compared to the preceding months, September's precipitation is noteworthy, as it aligns with the broader pattern of heightened rainfall, hinting at an elusive shift in seasonal dynamics that drives Carlsbad's charming climate.
In Carlsbad, United States, September brings a slight uptick in humidity, reaching about 71%. This marks a subtle recovery from the summer months, where levels hovered around 66% to 69% between June and August. As the seasons transition, this slight increase in humidity hints at the impending arrival of fall, with October mirroring September's levels. Notably, this is a significant dip from the peak humidity levels seen in the winter months of November and December, which soar to an average of 82% and 80%, respectively. The shift in humidity throughout the year reveals a rhythm of dry and damp, painting a vivid picture of Carlsbad's climate tapestry.
In September, Carlsbad experiences a UV Index of 11, categorizing it as extreme exposure. This signifies a continuation of the high UV levels seen during the summer months, with a burn time of just 10 minutes for unprotected skin. Following a pattern of rising UV intensity from January's moderate level of 5, the UV Index peaks dramatically from April through August, reaching its highest point in June at 13. Although September sees a slight dip, it remains critical for residents and visitors to protect themselves against the sun's harmful rays. As autumn approaches with a shift in temperatures, it’s essential to stay informed about UV levels. For more details, visit Carlsbad UV Index.
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As summer gracefully transitions to fall, September in Carlsbad brings a comforting blend of warm days and ample sunshine, shining for 304 hours this month. This marks a slight dip from the sun-soaked heights of July with 370 hours but remains a radiant glow compared to the earlier months. Notably, the month continues the trend of abundant daylight, following the peak in May when residents enjoyed 364 hours of sunlight. With the sun still lingering brightly as summer’s warmth begins to fade, September becomes an ideal time for outdoor activities and soaking in the last rays of summer, while hinting at the cozy embrace of autumn ahead.
In Carlsbad, September boasts a promising 72% chance of sunny weather, highlighting a trend of favorable conditions as summer transitions into fall. After the peak brightness of spring and early summer, where chances hovered between 59% and 75%, September maintains a relatively high probability of sunshine, outshining the cloudier months of July and August. As the year progresses, the likelihood of sun increases significantly in October, reaching an impressive 87%. Overall, September serves as a delightful prelude to the sunny days ahead, making it an ideal time for outdoor activities in this coastal paradise.
As September arrives in Carlsbad, daylight begins its gentle decline, offering 12 hours of sunshine each day. This marks a subtle shift after the peak summer months of June and July, when daylight stretched to a generous 14 hours. Following the warmth of August's 13 hours, September signals a transition towards the shorter days of fall. This pattern reflects a broader trend throughout the year, where daylight gradually increases from the depths of winter in January, peaking in the summer, before gradually retreating again. As the days grow shorter, Carlsbad residents can savor the last golden rays of summer while anticipating the cozy rhythms of autumn.
In Carlsbad, September marks a slight dip in the average wind speed, measuring 3.4 m/s (8 mph), compared to the breezier months of spring with March peaking at 4.8 m/s (11 mph). This gentle breeze creates a comfortable atmosphere, inviting residents and visitors alike to enjoy outdoor activities as the summer heat begins to fade. The wind patterns throughout the year reveal a notable trend: the strong gusts of early spring give way to more tranquil conditions in the summer, with July recording the lowest speed at 2.8 m/s (6 mph). As the seasons shift towards autumn, the winds moderate, setting the stage for a serene end-of-summer vibe. Overall, September strikes a perfect balance, embodying the transition of nature while offering a refreshingly light breeze.
The weather in Carlsbad 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 Carlsbad and find detailed weather information for every month.
September and January present striking contrasts in weather. In September, temperatures range from a mild 8°C (47°F) at night to a warm average of 25°C (78°F), peaking at a scorching 38°C (101°F). Humidity levels hover around 71%, and there's about 29 mm (1.1 in) of precipitation over six days, indicating a relatively wet month. In contrast, January boasts much colder temperatures, with nightly lows plunging to -10°C (15°F) and averaging just 8°C (46°F), while highs reach a more moderate 27°C (80°F). The month is drier, with only 12 mm (0.5 in) of precipitation over just two days, and humidity slightly higher at 75%. For more details, visit Carlsbad weather in January.
September and February present strikingly different weather conditions. In September, temperatures range from a minimum of 8°C (47°F) to a scorching maximum of 38°C (101°F), making it a warm month with an average temperature of 25°C (78°F). This month also experiences 29 mm (1.1 in) of precipitation across six days, alongside a humidity level of 71%. In contrast, February features much chillier temperatures, with a minimum of -15°C (6°F) and an average of 10°C (50°F), peaking at a maximum of 31°C (88°F). Precipitation is notably lower at 11 mm (0.4 in) over just one day, while humidity remains slightly higher at 74%. For more specific details on weather trends, you can visit Carlsbad weather in February.
September and March present distinct weather patterns, reflecting the transition from summer to autumn and winter to spring, respectively. In September, temperatures are generally warmer, with an average of 25°C (78°F) and highs reaching up to 38°C (101°F). This month often sees higher humidity at 71%, alongside about 29 mm (1.1 in) of precipitation spread over 6 days. In contrast, March offers a cooler climate, with an average temperature of 15°C (59°F) and maximums reaching 34°C (93°F). It typically has lower humidity at 61% and slightly less rainfall, at 24 mm (0.9 in), occurring over only 3 days. For a closer look at March weather, check out Carlsbad weather in March.
In comparing the weather of September and April, it is clear that September tends to be warmer overall, with average temperatures peaking at around 25°C (78°F) and maximum temperatures reaching as high as 38°C (101°F). In contrast, April features a cooler average of 20°C (67°F), with maximum temperatures typically not exceeding 36°C (97°F). Additionally, September experiences more frequent rainfall, with precipitation recorded on 6 days and totaling 29 mm (1.1 in), while April sees much less precipitation, only 12 mm (0.5 in) over just 1 day. Humidity is also higher in September at 71%, compared to 61% in April. For more specific insights into April weather, you can explore Carlsbad weather in April.
In comparing the weather between September and May, we see some notable differences despite both months having a similar average temperature of around 25°C (77°F). September tends to be warmer, with maximum temperatures reaching up to 38°C (101°F), whereas May can peak at 40°C (104°F). Rainfall is more frequent in September, with precipitation occurring on six days totaling 29 mm (1.1 in), compared to only three days in May with a lighter 11 mm (0.4 in). Additionally, humidity levels are slightly higher in September at 71%, while May enjoys a more comfortable 67%. For a detailed look at May weather, you can explore Carlsbad weather in May.
In comparing the weather between September and June, it's clear that June tends to be warmer overall. While September boasts a minimum temperature of 8°C (47°F) and an average of 25°C (78°F), June starts at a higher minimum of 14°C (58°F) and averages 29°C (84°F). Additionally, June can reach maximum temperatures of 42°C (109°F) compared to September's peak of 38°C (101°F). Both months experience the same level of precipitation at 29 mm (1.1 in), although June sees it over just 3 days compared to September's 6 days. Humidity levels are relatively similar, with September at 71% and June slightly lower at 69%. For more information on the specific weather conditions in June, check out Carlsbad weather in June.
When comparing the weather in September to that of July, there are notable differences in temperature and humidity. September experiences a broader temperature range with minimums dropping to 8°C (47°F) and maximums reaching up to 38°C (101°F), resulting in an average temperature of 25°C (78°F). In contrast, July boasts warmer temperatures overall, with minimums at 18°C (65°F) and maximums hitting 44°C (111°F), leading to a higher average of 29°C (85°F). Rainfall is slightly more frequent in September with 29 mm (1.1 in) over 6 days compared to July's 23 mm (0.9 in) over just 4 days. Humidity remains relatively high in both months, with September at 71% and July slightly lower at 69%. For a deeper look into the July weather specifics, check out Carlsbad weather in July.
In comparing the weather of September and August, September registers a significant drop in minimum temperatures, with a low of 8°C (47°F) compared to August's warmer minimum of 17°C (63°F). The average temperature in September is also noticeably lower at 25°C (78°F), whereas August boasts a higher average of 29°C (84°F). Additionally, September experiences a maximum temperature of 38°C (101°F), which, while still hot, is less extreme than August's peak of 43°C (109°F). Precipitation is slightly lower in September at 29 mm (1.1 in) over 6 days, compared to August's 34 mm (1.3 in) over 5 days. Humidity is higher in September at 71%, compared to 66% in August, contributing to a potentially more oppressive atmosphere despite the cooler temperatures. For more detailed insights into August's climate, check out Carlsbad weather in August.
September and October showcase a notable shift in weather patterns. In September, temperatures range from a minimum of 8°C (47°F) to a sweltering maximum of 38°C (101°F), with an average of 25°C (78°F), while October sees much cooler nights with a minimum of -3°C (28°F) and an average temperature dropping to 19°C (66°F). Precipitation is slightly higher in October, measuring 31 mm (1.2 in) over only 3 days, compared to September's 29 mm (1.1 in) spread over 6 days, revealing a trend towards drier conditions. Both months maintain a humidity level of 71%, providing a consistent feel in the air. For more details on October weather, check Carlsbad weather in October.
In September, the weather is typically warm, with minimum temperatures around 8°C (47°F) and an average high of 25°C (78°F), peaking at a scorching 38°C (101°F). During this month, the region experiences about 29 mm (1.1 in) of precipitation over approximately 6 days, coupled with a humidity level of 71%. In contrast, November brings a notable shift, with minimum temperatures dropping to -4°C (25°F) and an average temperature of 13°C (56°F), while the maximum reaches a comfortable 31°C (88°F). Precipitation decreases to 16 mm (0.6 in) spread over just 2 days and humidity increases slightly to 82%. For more detailed insights, check out Carlsbad weather in November.
In comparing the weather of September and December, notable differences emerge. September typically boasts warm temperatures with a minimum of 8°C (47°F) and an average of 25°C (78°F), reaching highs of 38°C (101°F). In contrast, December experiences much cooler conditions, with temperatures dropping to a minimum of -5°C (23°F) and an average of only 9°C (49°F), peaking at 27°C (80°F). Additionally, September sees relatively more precipitation, totaling 29 mm (1.1 in) over about 6 days, while December is much drier, with just 7 mm (0.3 in) of rain over 1 day. Humidity remains similar, with September at 71% and December slightly higher at 80%. For a more detailed look at December weather, check Carlsbad weather in December.
As September rolls in, Carlsbad experiences a notable transition from the scorching heat of summer to a more moderate climate. With temperatures peaking around 38°C, this month retains some summer warmth, but the average dips to a comfortable 25°C. In contrast to the dry summer months, September also brings a touch of humidity at 71%, along with occasional rainfall, averaging 29 mm over about 6 days. This combination of warm days and cooler nights makes September a unique time to enjoy the beauty of Carlsbad while also hinting at the upcoming autumn. For those seeking to explore more about how the weather throughout the year varies, check out Carlsbad Climate.