September Weather in Brooklyn, United States

Last updated: February 24, 2025

September in Brooklyn brings a dynamic mix of weather that transitions from the lingering warmth of summer to the crispness of autumn. With maximum temperatures soaring to 33°C (92°F) and an average of 21°C (70°F), residents can still enjoy the tail end of beach days. However, nights can dip to a brisk 9°C (49°F), reminding all that fall is approaching. This month also sees about 92 mm (3.6 in) of precipitation over 9 days, contributing to a humidity level of 68%. Whether you're savoring the last rays of summer or preparing for sweater weather, September in Brooklyn is a season of change and charm.

September Temperature in Brooklyn

In September, Brooklyn experiences a delightful transition as temperatures begin to shift from the sweltering summer heat to the crisper autumn air. With a minimum temperature of 9°C (49°F) and an average hovering around 21°C (70°F), the early fall days are pleasantly warm, making it ideal for outdoor activities. The maximum daytime highs can still reach up to 33°C (92°F), allowing residents to savor the lingering warmth of summer while enjoying cooler evenings. This month marks a distinct cooling trend, as it sets the stage for the cooler temperatures that October brings, contrasting sharply with the peak summer heat of July and August. As the leaves start to change, September in Brooklyn strikes a perfect balance, inviting both relaxation and adventure.

September Weather in Brooklyn: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Brooklyn, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends.
JanFebMarAprMayJunJulAugSepOctNovDec343642526272787670604638
Data source: Temperature data for Brooklyn generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Brooklyn

In September, Brooklyn experiences a moderate level of precipitation, with 92 mm (3.6 in) of rainfall over 9 days. This marks a noticeable dip from the more humid summer months of July and August, which see higher totals of 148 mm (5.8 in) and 127 mm (5.0 in), respectively. As the season transitions into fall, the number of rainy days decreases, suggesting a shift towards drier conditions. Interestingly, the precipitation trend indicates a gradual tapering off as the year progresses, setting the stage for October's slightly wetter weather at 128 mm (5.0 in) over 10 days. By recognizing these trends, residents can anticipate the shifting climate patterns and prepare for the upcoming months.

September Precipitation Trends in Brooklyn

The chart displays monthly precipitation patterns in Brooklyn, with values for each month alongside September's data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September's conditions compare to those of other months.
JanFebMarAprMayJunJulAugSepOctNovDec6710298112114921481279212883106
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Brooklyn

As September rolls in, Brooklyn experiences a slight uptick in humidity, settling at around 68%. This marks a subtle rise from the drier summer months of July and August, which saw humidity levels dip to 62% and 65%, respectively. Despite this increase, September remains relatively mild compared to the winter months, where humidity levels soar to 84% in January and stay high throughout the fall. The transition to autumn introduces a comfortable balance, as the lingering warmth of summer meets the crispness of approaching October, which can bring even more moisture, raising humidity to 74%. Thus, September serves as a bridge, gently easing Brooklyn into the wetter, cooler seasons ahead.

September Average Humidity in Brooklyn

This chart illustrates the average monthly humidity levels in Brooklyn, with September's data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, allowing you to see how September's humidity levels compare to other months.
JanFebMarAprMayJunJulAugSepOctNovDec84%82%81%78%70%69%62%65%68%74%82%80%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Brooklyn

As summer transitions to fall, the UV Index in Brooklyn maintains a very high level, with September registering an index of 8. This signifies a notable decline from the peak August levels, but residents should still practice caution, as direct sun exposure can lead to skin burns in just 15 minutes. Following this trend, the UV Index begins to drop more significantly in October, moving to a high category at 6. Overall, September's UV Index continues to reflect the lingering summer intensity, urging Brooklynites to stay sun-safe as they relish the last warm days. For more detailed insights, visit Brooklyn UV Index.

Maximum UV Index Levels in Brooklyn for September

The chart shows the monthly maximum UV Index (UVI) for Brooklyn in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec35681010998642
Data source: Brooklyn September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

September Sunshine in Brooklyn

September in Brooklyn boasts a remarkable 272 hours of sunshine, making it one of the sunniest months of the year. As summer fades, sunlight begins to taper from the peak of 339 hours in July, yet still outshines the earlier months. The gradual decline from the vibrant summer to the crisp autumn is evident, as September experiences more sunlight than both October and November, which receive 218 and 208 hours, respectively. This trend reflects the city’s inviting transition, where the warmth of late summer lingers, offering Brooklynites one last taste of sunshine before the cooler months set in.

Monthly Sunshine Duration in Brooklyn: September Highlighted

The September sunshine duration represents the total number of hours Brooklyn experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec148h177h248h238h271h310h339h309h272h218h208h175h
Data source: Brooklyn September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Brooklyn During September

As summer transitions to fall, September in Brooklyn offers a respectable 45% chance of sunny weather, aligning closely with the monthly average for much of the year. While the peak sunniness appears in March at 57%, and November showcases a surprisingly bright 55%, September maintains a steady position amid fluctuating summer conditions. This month's likelihood of sun contrasts with the notably lower probabilities experienced in August, where the chance drops to just 29%. Notably, September’s sunniness mirrors the lower rates seen in spring, signaling that although the warmth of summer is fading, there's still a promising chance to soak up some late-season rays.

Percentage of Sunny Days in September in Brooklyn

The chart illustrates the percentage of sunny days in Brooklyn throughout the year, with September highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Brooklyn experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec48%31%57%45%42%39%43%29%45%37%55%31%
Data source: Brooklyn September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Brooklyn in September

As summer transitions to autumn, September in Brooklyn witnesses a slight yet noticeable shift in daylight duration, averaging 12 hours of sunlight. This marks a gentle decline from the peak of 15 hours in June, with each passing month embracing shorter days. Following the vibrant summer months, September's daylight offers a blend of lingering warmth and the early whispers of fall, as nature prepares for the cooler months ahead. Interestingly, October will continue this trend, reducing daylight further to 11 hours, reminiscent of the gradual dimming we experience as we approach the winter solstice. This rhythmic ebb and flow of daylight not only captures the essence of each season but also invites Brooklynites to savor the beauty of the changing landscape.

Average Daylight Hours in Brooklyn for September

The chart illustrates the variation in daylight duration in Brooklyn throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec9h 36m10h 39m11h 58m13h 19m14h 28m15h 2m14h 43m13h 42m12h 24m11h 3m9h 53m9h 17m
Data source: Brooklyn daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Brooklyn

As summer transitions to autumn in Brooklyn, September brings a subtle uptick in wind speed, averaging 3.1 m/s (7 mph), a refreshing change from the gentle breezes of the preceding months. Throughout the summer, the winds dipped to their lowest, with July and August averaging just 2.6 m/s (6 mph) and 2.5 m/s (6 mph) respectively. This seasonal shift marks a gradual return to the more invigorating winds typical of late summer and early fall, reminiscent of the lively atmosphere that accompanies the vibrant streets of the borough. The consistency of 3.1 m/s in September sets the stage for a breezy October and November, inviting Brooklynites to savor the crisp air and vibrant colors of the changing leaves.

Average September Wind Speed in Brooklyn

The chart displays monthly wind speed patterns in Brooklyn, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.53.43.73.43.32.82.62.53.1 m/s3.13.12.9
Data source: Brooklyn September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Brooklyn Compares to Other Months

The weather in Brooklyn 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 Brooklyn and find detailed weather information for every month.

September and January present stark contrasts in weather conditions. September boasts milder temperatures, with averages around 21°C (70°F) and highs reaching up to 33°C (92°F), while January plunges into the cold, with average temperatures around 1°C (34°F) and lows dipping to -18°C (-1°F). In terms of precipitation, September experiences more rainfall, totaling 92 mm across 9 days, compared to January's 67 mm over 7 days. Moreover, humidity levels are notably higher in January at 84%, compared to September's 68%, contributing to a much different overall feel between these two months. For more details, visit Brooklyn weather in January.

September and February present stark contrasts in weather conditions. In September, temperatures range from a mild minimum of 9°C (49°F) to a warm maximum of 33°C (92°F), with an average of 21°C (70°F) and relatively moderate humidity at 68%. However, this month experiences a fair amount of precipitation, totaling 92 mm (3.6 in) over about 9 days.

In contrast, February is considerably colder, with temperatures dropping to a minimum of -16°C (4°F) and only reaching a maximum of 20°C (68°F), averaging just 2°C (36°F). The month sees slightly higher precipitation at 102 mm (4.0 in) across about 10 days, and humidity is notably higher at 82%. For a closer look at February weather specifics, check out Brooklyn weather in February.

In comparing the weather of September and March, there are notable differences in temperature and overall climate. September boasts a much warmer average temperature of 21°C (70°F), with maximum highs reaching up to 33°C (92°F), while March is significantly cooler, featuring an average temperature of only 5°C (42°F) and a maximum of 25°C (77°F). Both months experience considerable precipitation, with September recording 92 mm (3.6 in) over 9 days and March slightly higher at 98 mm (3.8 in) over 10 days. Additionally, March has a higher humidity level at 81%, compared to September's 68%, contributing to a chillier feel. For a detailed look at March weather specifics, visit Brooklyn weather in March.

In comparing the weather between September and April, we see a notable contrast in temperatures and conditions. September boasts a wider temperature range, with minimums around 9°C (49°F) and maximums reaching up to 33°C (92°F), yielding an average of 21°C (70°F). With 92 mm (3.6 in) of precipitation over 9 days and a relative humidity of 68%, the month presents a warm and relatively humid environment.

On the other hand, April experiences cooler temperatures, with minimums dipping to -1°C (31°F) and maximums of 27°C (82°F), averaging around 11°C (52°F). It sees slightly higher precipitation at 112 mm (4.4 in) over 12 days, along with increased humidity at 78%. This makes April a wetter and chillier month overall. For more detailed insights, you can visit Brooklyn weather in April.

September and May exhibit distinct weather patterns that reflect the transition between summer and autumn. In September, temperatures range from a minimum of 9°C (49°F) to a maximum of 33°C (92°F), with an average of 21°C (70°F). The month experiences around 92 mm (3.6 in) of precipitation over approximately 9 days, accompanied by a humidity level of 68%. Conversely, May features cooler temperatures, with lows of 3°C (37°F) and highs reaching 31°C (88°F), averaging 17°C (62°F). It experiences slightly higher precipitation at 114 mm (4.5 in) over about 13 days, while maintaining a similar humidity of 69%. For a closer look at what to expect, check out Brooklyn weather in May.

In comparing the weather of September and June, both months showcase similar precipitation levels, with September receiving 92 mm over 9 days and June also seeing 92 mm but over 13 days. The temperature in September ranges from a minimum of 9°C (49°F) to a maximum of 33°C (92°F), while June is slightly warmer, with a low of 10°C (50°F) and a high of 35°C (94°F). Humidity levels are quite comparable, with September at 68% and June at 69%. For a closer look at June's climate specifics, you can visit Brooklyn weather in June.

In comparing the weather of September and July, September exhibits a broader temperature range, with minimums dipping to 9°C (49°F) and maximums reaching 33°C (92°F), while the average temperature is a comfortable 21°C (70°F). In contrast, July is typically hotter, with minimums of 17°C (62°F) and maximums soaring to 36°C (96°F), resulting in a higher average of 26°C (78°F). Rainfall is more frequent in July, with 148 mm (5.8 in) over 13 days compared to September's 92 mm (3.6 in) over 9 days. Although September has slightly higher humidity at 68%, July feels less humid at 62%. For more detailed insights, you can explore Brooklyn weather in July.

Comparing the weather between September and August reveals some notable differences. September experiences a wider temperature range, with minimums dropping to 9°C (49°F) and maximums reaching up to 33°C (92°F), while August maintains generally warmer conditions, with minimums around 16°C (61°F) and maximums peaking at 34°C (93°F). Precipitation levels also vary significantly; September sees 92 mm (3.6 in) of rain over 9 days, compared to August's higher total of 127 mm (5.0 in) over 14 days. Additionally, September has a slightly higher humidity level at 68%, compared to August's 65%. For more detailed insights, you can check Brooklyn weather in August.

In September, temperatures range from a mild 9°C (49°F) at night to a warm 33°C (92°F) during the day, resulting in an average of 21°C (70°F). The month experiences 92 mm (3.6 in) of rainfall over 9 days, with a humidity level of 68%. In contrast, October sees a significant drop in average temperatures, with minimums reaching 4°C (39°F) and an average of 16°C (61°F), even though daytime highs can still reach 33°C (91°F). Precipitation increases to 128 mm (5.0 in) over 10 days, accompanied by a slight rise in humidity to 74%. For more detailed information, you can check Brooklyn weather in October.

September and November showcase a notable shift in weather characteristics. In September, temperatures range from a mild 9°C (49°F) to a hot 33°C (92°F), with an average of 21°C (70°F), indicating a warm transition from summer to autumn. Humidity is relatively moderate at 68%, and the month experiences 92 mm (3.6 in) of rainfall over 9 days. In contrast, November brings much cooler temperatures, with minimums plunging to -9°C (17°F) and an average of just 8°C (47°F). Although the maximum temperature reaches a pleasant 24°C (75°F), the overall trend is decidedly chillier. November sees a slight decrease in precipitation to 83 mm (3.3 in) over 8 days, accompanied by an increase in humidity to 82%. For more details, you can explore Brooklyn weather in November.

The weather in September features a wide range of temperatures, with a minimum of 9°C (49°F) and a maximum that can reach up to 33°C (92°F), resulting in a pleasant average temperature of 21°C (70°F). In contrast, December sees a significant drop in temperatures, where the minimum can plummet to -11°C (13°F) and the average lingers around just 4°C (39°F). While September experiences 92 mm (3.6 in) of rainfall over 9 days, December has slightly more precipitation at 106 mm (4.2 in) but spreads it over 10 days, contributing to a higher humidity level of 80%. For more details, check out Brooklyn weather in December.

Compare Brooklyn's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Brooklyn

As we transition into September, Brooklyn's weather offers a delightful mix of warm days and cooler evenings, setting it apart from the scorching summer months. With average temperatures hovering around a comfortable 21°C (70°F), the city experiences a refreshing change from the peak heat, while still occasionally flirting with highs of 33°C (92°F). This month also brings a moderate amount of rainfall, with about 92 mm (3.6 in) spread over nine days, contributing to the city's lush early autumn scenery. Combined with a humidity level of 68%, September provides a unique blend of warmth and freshness that invites both locals and visitors to enjoy outdoor activities. For a deeper look into the yearly weather patterns, explore Brooklyn Climate.