Last updated: February 24, 2025
Experience the delightful September weather in Kailua, United States, characterized by a comfortable average temperature of 26°C (79°F). Daily highs can reach a pleasant 29°C (85°F), while nighttime lows drop to around 22°C (72°F), creating an ideal climate for outdoor activities. This month sees about 37 mm (1.5 in) of precipitation spread across 12 days, contributing to the lush Hawaiian landscape. With humidity levels hovering at 82%, the air feels warm yet invigorating, making September a perfect time to explore the beauty of Kailua’s beaches and nature.
As summer gracefully transitions into fall, September temperatures in Kailua embrace warmth and comfort, reflecting a delightful climate that invites both locals and visitors to enjoy the outdoors. With minimums averaging around 22°C (72°F) and maximums soaring to 29°C (85°F), the month maintains a lively average of 26°C (79°F)—keeping the spirit of summer alive a little longer. This trend shows a slight increase from the previous months, coinciding with the peak of summer warmth in August. The consistent warmth throughout September not only enhances the lush beauty of the island but also provides the perfect backdrop for beach days, sunset strolls, and vibrant outdoor activities. As the month draws to a close, Kailua remains a cherished oasis, blending tropical bliss with island charm.
In Kailua, September witnesses a modest decline in precipitation, with 37 mm (1.5 in) of rainfall recorded over approximately 12 days. This trend follows the wetter months of July and August, where rain totals of 39 mm and 41 mm respectively contributed to a humid summer. As autumn approaches, the precipitation pattern hints at a gradual transition, with October expected to bring a more significant increase in rainfall to 66 mm (2.6 in) over 15 days. This shift suggests that while September offers a brief respite, the seasonal rains are poised to return, setting the stage for the wetter months ahead.
September in Kailua sees humidity levels at 82%, maintaining a comfortable equilibrium as the summer months transition into autumn. This month closely follows August's peak humidity of 83%, reflecting a slight dip that leads into October’s average of 81%. Throughout the year, Kailua experiences consistently high humidity, with most months hovering between 78% and 83%, peaking in the mid-summer to early fall. The gradual decrease from the summer highs signals the onset of more temperate conditions, yet the moderate humidity continues to define Kailua's lush, tropical atmosphere.
In September, Kailua experiences a UV Index of 12, aligning closely with the extreme exposure levels seen during the peak summer months. This month marks a slight decrease from the highest readings of 13 observed in July and August, yet it remains critical for residents and visitors to take precautions, with a burn time of just 10 minutes. As summer transitions into fall, the UV exposure continues to be significant, reminding us that vigilance is essential for skin protection year-round. For more detailed information on UV trends throughout the year, visit Kailua UV Index.
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As September arrives in Kailua, the island basks in 319 hours of glorious sunshine, signaling a slight dip from the blazing summer months but still offering an abundance of light and warmth. The trend of increasing daylight hours from January's 219 hours peaks in July at 349 hours, creating a vibrant crescendo of summer energy. This month’s sunshine provides the perfect backdrop for outdoor activities, maintaining a delightful balance as the days gradually shorten into autumn. While October sees a minor decrease to 301 hours, the lingering warmth of September's sunshine continues to invite both locals and visitors to embrace the beauty of Kailua's natural landscape.
September in Kailua, United States, offers a pleasant chance of sunny weather, with a 59% likelihood of clear skies. Following the peak of summer, where sunny days can reach up to 63% in August, September maintains this favorable trend while transitioning into autumn. The chance of sunshine stays relatively steady compared to the preceding months, nestled among the mid-range probabilities observed throughout the year. As temperatures begin to cool down, this blend of decent sunshine and mild weather makes September an inviting choice for outdoor activities and leisurely beach days.
As September rolls in, Kailua enjoys a wholesome 12 hours of daylight, maintaining the balance seen in previous months like April and August. This marks a gradual transition from the peak summer months, where daylight extended to a generous 13 hours. Following the vibrant energy of summer, the daylight begins to wane, heralding the arrival of autumn. With daylight starting to decrease ahead of October’s 11 hours, September serves as a bridge, providing ample time for outdoor activities while hinting at the cozy changes that the coming months will bring.
In September, Kailua experiences an invigorating return of average wind speeds at 6.1 m/s (14 mph), mirroring the breezy conditions of January. This continuation of moderate winds suggests a subtle yet refreshing transition as summer starts to wane. Following a peak in July, where winds reached 7.0 m/s (16 mph), the autumn months maintain a favorable balance—neither too gusty nor too calm. As we move towards October, the winds barely increase to 6.2 m/s (14 mph), maintaining the pleasant coastal ambiance that residents and visitors cherish. This steady trend highlights September as a bridge, seamlessly connecting the warmth of summer with the cooler breezes of fall, making it an ideal time for outdoor activities and enjoying Kailua's stunning scenery.
The weather in Kailua 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 Kailua and find detailed weather information for every month.
When comparing the weather in September and January, September typically boasts warmer temperatures, with an average high of 29°C (85°F) compared to January's average maximum of 27°C (80°F). September also experiences higher humidity levels at 82%, as opposed to January's 78%. Precipitation is slightly higher in September, with 37 mm (1.5 in) over 12 days, while January sees 34 mm (1.3 in) spread over 9 days. For more detailed information about January weather, you can visit Kailua weather in January.
September and February present distinct weather patterns, with September generally being warmer and slightly more humid. In September, the minimum temperature typically hovers around 22°C (72°F), peaking at a comfortable 29°C (85°F), while February sees cooler temperatures, with a minimum of 16°C (62°F) and a maximum of 26°C (79°F). Additionally, February experiences higher precipitation, averaging 82 mm (3.2 in) over about 14 days, compared to September's 37 mm (1.5 in) across 12 days. Despite this, the humidity remains relatively similar, with February at 79% and September at 82%. For a more detailed look at February weather, check out Kailua weather in February.
In comparing the weather between September and March, you can observe key differences in temperature and precipitation. September tends to be warmer with minimum temperatures around 22°C (72°F) and an average of 26°C (79°F), while March records slightly cooler temperatures, with a minimum of 19°C (66°F) and an average of 22°C (73°F). Precipitation also varies significantly; September experiences 37 mm (1.5 in) of rain over 12 days, whereas March sees a higher amount with 89 mm (3.5 in) spread over 16 days. Additionally, humidity levels are relatively high in both months, with September at 82% and March at 78%. For more detailed information about weather specifics, you can check out Kailua weather in March.
In comparing the weather between September and April, September generally enjoys warmer temperatures, with a minimum of 22°C (72°F) and an average of 26°C (79°F), while April's minimum temperature is slightly cooler at 19°C (66°F) and an average of 23°C (74°F). However, April tends to have higher precipitation, with 51 mm (2.0 in) over approximately 13 days, compared to September's 37 mm (1.5 in) over 12 days. Humidity levels remain quite similar, with September at 82% and April slightly lower at 81%. For more details on weather patterns, check out Kailua weather in April.
In comparing the weather of September and May, both months exhibit warm temperatures, but September generally feels a bit warmer, with an average temperature of 26°C (79°F) compared to May's 24°C (75°F). The maximum temperatures in September reach up to 29°C (85°F), slightly higher than May’s maximum of 28°C (82°F). However, May experiences slightly more precipitation, with 44 mm (1.7 in) falling over 13 days compared to September’s 37 mm (1.5 in) over 12 days. Interestingly, both months share the same humidity level of 82%, giving them a similarly tropical feel. For more detailed insights, you can explore Kailua weather in May.
Both September and June bring warm temperatures to the region, with minimums around 22°C (72°F) and maximums not far apart—29°C (85°F) in September and 28°C (83°F) in June. However, September tends to be slightly warmer overall, averaging 26°C (79°F) compared to June’s average of 25°C (77°F). Precipitation varies between the two months, with September experiencing 37 mm (1.5 in) over 12 days, while June sees higher rainfall at 56 mm (2.2 in) over 11 days. The humidity remains consistent in both months at 82%, contributing to the tropical feel. For more details on June weather, check out Kailua weather in June.
In comparing the weather of September and July, both months share similar temperature ranges, with September seeing a minimum of 22°C (72°F) and an average of 26°C (79°F), slightly warmer than July’s maximum of 28°C (83°F). Precipitation levels are comparable, with September receiving 37 mm (1.5 in) over 12 days, while July has slightly more rainfall at 39 mm (1.5 in) across 16 days. Humidity remains high in both months, with September at 82% and July at 83%, contributing to the tropical feel. For more specific details, you can check out Kailua weather in July.
In comparison to August, September experiences slightly cooler temperatures, with a minimum of 22°C (72°F) compared to August's 23°C (73°F). Both months share the same average and maximum temperatures of 26°C (79°F) and 29°C (85°F), respectively. However, September sees a slight decrease in precipitation, measuring 37 mm (1.5 in) over 12 days, while August has 41 mm (1.6 in) across the same number of days. Humidity levels remain relatively consistent, with September at 82% and August at 83%. For those interested in more details, you can check out Kailua weather in August.
September and October exhibit noticeable similarities in temperature, with September having a slightly higher average of 26°C (79°F) compared to October's average of 25°C (78°F). Both months share the same minimum temperature of 22°C (72°F) and a maximum of 29°C (85°F). However, October experiences increased rainfall, with precipitation rising from 37 mm (1.5 in) in September to 66 mm (2.6 in) in October, as well as an uptick in the number of rainy days from 12 to 15. Humidity levels remain quite consistent, with September at 82% and October slightly lower at 81%. For more detailed information on the weather in October, check out Kailua weather in October.
In September, temperatures are generally warmer, with minimums around 22°C (72°F) and an average of 26°C (79°F), while November sees slightly cooler averages, with a minimum of 20°C (69°F) and an overall average of 25°C (76°F). Both months have a maximum temperature of 29°C (84°F) and experience high humidity, though September boasts a slightly higher level at 82%, compared to November's 80%. Precipitation is more frequent in November, with 48 mm (1.9 in) falling over 16 days, while September sees 37 mm (1.5 in) over 12 days. For more detailed insights, check out Kailua weather in November.
September and December exhibit notable differences in weather patterns. In September, temperatures are generally warmer, with minimums around 22°C (72°F) and maximums reaching up to 29°C (85°F). The humidity is relatively high at 82%, accompanied by moderate rainfall of 37 mm (1.5 in) over about 12 days. Conversely, December sees cooler temperatures, with a minimum of 18°C (65°F) and a maximum of 27°C (81°F). Rainfall increases significantly to 87 mm (3.4 in), spread across 16 days, while humidity slightly decreases to 79%. For more details on December weather, you can check Kailua weather in December.
September in Kailua brings a delightful transition as summer begins to wane. With average temperatures hovering around 26°C (79°F), the warmth is still palpable, but it's softened by the onset of slight humidity, often reaching 82%. This month also marks an increase in precipitation, with about 12 days seeing rain, amounting to 37 mm (1.5 in), making it a tad wetter compared to the drier summer months. These factors combine to create a unique, tropical ambiance that is distinct from the hotter, drier conditions earlier in the season, inviting both locals and visitors to enjoy the lush landscape. For more detailed insights into the overall climatic patterns, explore Kailua Climate.