September Weather in New York City, United States

Last updated: February 24, 2025

September in New York City reveals a dynamic climate, where summer's warmth lingers before the fall chill sets in. The maximum temperature can reach an impressive 33°C (92°F), while the average hovers around a comfortable 21°C (70°F). As the month unfolds, temperatures can dip to a refreshing 9°C (49°F) at night, showcasing the transition between seasons. However, residents and visitors alike should be prepared for occasional showers, with a total precipitation of 92 mm (3.6 in) spread over 9 days and humidity levels sitting at 68%. This blend of warmth, moisture, and vibrant city life makes September a unique time to experience the charm of New York.

September Temperature in New York City

As September rolls into New York City, the summer heat begins to fade, giving way to a pleasant transition into fall. With minimum temperatures averaging around 9°C (49°F) and delightful average highs reaching 21°C (70°F), this month strikes a perfect balance between warmth and coolness. The maximums soar up to 33°C (92°F) on warmer days, offering opportunities for lingering outdoor activities while evenings become refreshingly crisp. Compared to the sweltering summer months of July and August, September's milder weather invites residents and visitors alike to enjoy Central Park strolls and rooftop gatherings amidst the beautiful changing foliage.

September Weather in New York City: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in New York City, 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 New York City generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in New York City

September in New York City experiences a precipitation level of 92 mm (3.6 in), showcasing a relatively mild rainfall compared to the summer months. With 9 days of rain, the month marks a transition from the wetter season, as August recorded a heftier 127 mm (5.0 in) over 14 days. This decline in both precipitation amount and rainy days indicates that the city is beginning to settle into the drier autumn months, yet still maintains a balance of moisture necessary for the vibrant September foliage. Overall, September’s rainfall reflects a gentle tapering off as the city prepares for the more variable climate that October brings, which typically sees 128 mm (5.0 in) over 10 days.

September Precipitation Trends in New York City

The chart displays monthly precipitation patterns in New York City, 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.
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September Humidity in New York City

In September, New York City experiences a slight increase in humidity, averaging around 68%. This marks a subtle transition as summer's warmth begins to wane, following the drier months of July and August, which saw humidity levels dip to 62% and 65%, respectively. As fall approaches, the relative humidity edges upward, reminiscent of the earlier months of the year, particularly when January registers a notable 84%. This gradual rise indicates a shift in atmospheric conditions, setting the stage for the crispness of autumn while still holding onto the remnants of summer's humidity. Overall, September acts as a bridge, maintaining a comfortable level of moisture in the air, which fosters a vibrant and refreshing environment in the city as it transitions into the fall season.

September Average Humidity in New York City

This chart illustrates the average monthly humidity levels in New York City, 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 New York City

As September arrives in New York City, the UV Index remains notably high, peaking at 8, indicating a need for caution. The transition from the scorching summer months, where UV levels reached a maximum of 10, to early autumn reflects a slight decrease in solar intensity. With burn times collapsing to just 15 minutes, it’s crucial for residents and visitors alike to remain vigilant about sun protection as they enjoy the charming early fall. This pattern highlights a consistent trend of high UV exposure during this time of year, making it essential to stay informed about daily UV levels. For more information, visit New York City UV Index.

Maximum UV Index Levels in New York City for September

The chart shows the monthly maximum UV Index (UVI) for New York City 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: New York City 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 New York City

September in New York City shines with an impressive 272 hours of sunshine, marking the tail end of summer's radiant embrace. As the sun-drenched days of July peak at 339 hours and slightly taper off in August with 309 hours, September maintains a delightful glow that hints at the cooler autumn months ahead. This gradual decline in sunlight fosters a transition, as the hustle and bustle of city life blends with the vibrant hues of falling leaves. With October’s sunlight hours dropping to 218, September stands out as a time when the warmth lingers just a little longer, inviting both locals and visitors to revel in the city's beauty before the chill sets in.

Monthly Sunshine Duration in New York City: September Highlighted

The September sunshine duration represents the total number of hours New York City 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: New York City September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in New York City During September

As September rolls into New York City, the chances of basking in sunny weather remain promising, with approximately 45% of the month likely to shine bright. This marks a slight improvement from the summer months, where the likelihood dips to 29% in August and hovers around 39% in June. Interestingly, September's sunshine probability aligns closely with April’s 45%, suggesting an equal balance of sun and cloud as autumn approaches. Overall, while the transition into fall brings cooler temperatures, those looking for sun can still expect relatively favorable conditions during this early autumn month.

Percentage of Sunny Days in September in New York City

The chart illustrates the percentage of sunny days in New York City 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 New York City experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec48%31%57%45%42%39%43%29%45%37%55%31%
Data source: New York City September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in New York City in September

As summer gives way to autumn in New York City, September experiences a subtle decline in daylight, averaging 12 hours. This marks a gradual transition from the longest days of June, with an impressive 15 hours, and the vibrant warmth of July and August, which still boast 14 and 13 hours respectively. The gentle decrease in daylight signals the approaching fall, as October further diminishes to 11 hours. This rhythmic pattern reflects the city's seasonal shift, where the longer days of summer provide a warm farewell to the shorter, crisp days of autumn and winter. As nature begins to transform, the daylight duration reminds us of the cyclical beauty of the seasons.

Average Daylight Hours in New York City for September

The chart illustrates the variation in daylight duration in New York City 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: New York City daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in New York City

As September breezes into New York City, the average wind speed picks up slightly to 3.1 m/s (7 mph), nudging a bit above the summer lull. This marks a gentle transition from the sultry, stagnant air of July and August, which saw the lowest wind speeds of the year at 2.6 m/s (6 mph) and 2.5 m/s (6 mph), respectively. In contrast, September's winds begin to echo the invigorating gusts of spring, reminiscent of March's liveliness at 3.7 m/s (8 mph). This seasonal dance hints at an approaching autumn, where the winds will settle back to a steady rhythm, averaging 3.1 m/s (7 mph) through the following months. The evolving winds weave a narrative of change, inviting the city to embrace the crispness of fall while subtly reminding us of summer's fading warmth.

Average September Wind Speed in New York City

The chart displays monthly wind speed patterns in New York City, 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: New York City September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in New York City Compares to Other Months

The weather in New York City 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 New York City and find detailed weather information for every month.

In September, the weather in New York City is generally warm, with temperatures ranging from a minimum of 9°C (49°F) to a maximum of 33°C (92°F) and an average of 21°C (70°F). The humidity sits at a comfortable 68%, although the month sees a fair amount of rainfall, with 92 mm (3.6 in) of precipitation over about 9 days. In contrast, January brings a stark change, with much colder temperatures ranging from a minimum of -18°C (-1°F) to a maximum of 18°C (64°F), averaging just 1°C (34°F). The humidity rises to 84%, and while there's slightly less precipitation at 67 mm (2.7 in) over about 7 days, the cold makes the weather feel more biting. For more detailed information, you can check New York City weather in January.

September and February exhibit strikingly contrasting weather patterns. In September, temperatures range from a cool 9°C (49°F) at night to a warm average of 21°C (70°F) during the day, peaking at a high of 33°C (92°F), with 92 mm (3.6 in) of precipitation over approximately 9 days and a humidity level of 68%. In contrast, February sees much colder temperatures, with a chilling minimum of -16°C (4°F) and a much lower average of 2°C (36°F), reaching a maximum of 20°C (68°F). Precipitation increases slightly to 102 mm (4.0 in) over 10 days, accompanied by higher humidity at 82%. These differences highlight the transition from late summer warmth to the depths of winter's chill. For more details on the February weather, see New York City weather in February.

When comparing the weather in September and March, notable differences emerge. September boasts a much warmer average temperature, with lows around 9°C (49°F) and highs reaching up to 33°C (92°F), alongside a humidity level of 68%. In contrast, March is significantly cooler, with temperatures ranging from a minimum of -9°C (16°F) to a maximum of 25°C (77°F) and a higher humidity of 81%. Both months experience similar levels of precipitation, with September recording 92 mm (3.6 in) across 9 days and March slightly higher at 98 mm (3.8 in) over 10 days. For a detailed look at March weather, visit New York City weather in March.

When comparing the weather in September and April, it's clear that each month offers distinct characteristics. September has a wider temperature range, with minimums around 9°C (49°F) and maximums peaking at 33°C (92°F), making it generally warmer than April, where temperatures range from a chilly -1°C (31°F) to a milder 27°C (82°F). However, April experiences slightly higher precipitation, totaling 112 mm (4.4 in) over 12 days, compared to September's 92 mm (3.6 in) over 9 days. Humidity levels are also higher in April at 78%, compared to 68% in September, contributing to the feeling of dampness as spring transitions into summer. For more details, you can check New York City weather in April.

In comparing the weather of September and May, September tends to be warmer, with average temperatures around 21°C (70°F) compared to May's cooler average of 17°C (62°F). While both months experience a range of temperatures, September can reach highs of 33°C (92°F), whereas May's maximum temperature peaks at 31°C (88°F). Precipitation is slightly higher in May, with 114 mm (4.5 in) over 13 days, compared to September's 92 mm (3.6 in) spread across 9 days. Humidity levels are quite similar in both months, hovering around 68-69%. For a detailed look at May's weather, you can visit New York City weather in May.

In comparing the weather of September and June, both months exhibit relatively mild temperatures, with September averaging around 21°C (70°F) and June slightly warmer at 22°C (72°F). Maximum temperatures peak at 33°C (92°F) in September and reach up to 35°C (94°F) in June. Precipitation levels are the same in both months, totaling 92 mm (3.6 in), but June experiences a bit more rain, falling over 13 days compared to September's 9 days. Humidity is similar, with September at 68% and June at 69%. For more detailed insights on June weather, visit New York City weather in June.

When comparing the weather between September and July, there are noticeable differences. July boasts higher average temperatures, ranging from a minimum of 17°C (62°F) to a maximum of 36°C (96°F), while September features a broader temperature range with a minimum of 9°C (49°F) and a maximum of 33°C (92°F). Additionally, July experiences more precipitation, with 148 mm (5.8 in) over about 13 days compared to September's 92 mm (3.6 in) spread over 9 days. The humidity in September is slightly higher at 68%, compared to July's 62%. For more details about July's weather, visit New York City weather in July.

In September, the weather features cooler temperatures with a minimum of 9°C (49°F) and an average of 21°C (70°F), compared to August's higher minimum of 16°C (61°F) and an average of 25°C (76°F). Although September reaches a similar maximum temperature of 33°C (92°F) as August's 34°C (93°F), the higher precipitation in August (127 mm over 14 days) outpaces September's 92 mm over 9 days. Additionally, September's humidity is slightly higher at 68% compared to August’s 65%. For more detailed insights, check out New York City weather in August.

September and October witness a notable shift in weather patterns, with October generally feeling cooler and more humid. In September, temperatures range from a minimum of 9°C (49°F) to a maximum of 33°C (92°F), averaging around 21°C (70°F), while October sees a drop in average temperature to 16°C (61°F), with a minimum of 4°C (39°F) and similar maximums. Precipitation also increases in October, reaching 128 mm (5.0 in) over 10 days compared to September's 92 mm (3.6 in) over 9 days. Additionally, humidity rises slightly from 68% in September to 74% in October, contributing to the month’s brisker feel. For more details, check out New York City weather in October.

September offers a warm climate with temperatures ranging from a mild 9°C (49°F) at night to a hot 33°C (92°F) during the day, averaging around 21°C (70°F). It experiences about 92 mm (3.6 in) of precipitation over approximately 9 days, with humidity levels around 68%. In contrast, November sees a significant drop in temperatures, with the minimum falling to -9°C (17°F) and an average of 8°C (47°F), while the daily maximum reaches a comfortable 24°C (75°F). The month brings slightly less rainfall, at 83 mm (3.3 in) over 8 days, and higher humidity at 82%. For a closer look at weather patterns, check out New York City weather in November.

September and December showcase strikingly different weather patterns. In September, temperatures range from a mild 9°C (49°F) at night to a warm 33°C (92°F) during the day, with average temperatures around 21°C (70°F). The month experiences moderate rainfall of 92 mm (3.6 in) over approximately 9 days, and humidity levels hover around 68%. In contrast, December brings much colder conditions, with temperatures dropping to a minimum of -11°C (13°F) and an average of just 4°C (39°F). Though December has slightly higher precipitation at 106 mm (4.2 in) over about 10 days, the humidity also increases to around 80%. For a more detailed look at December's weather in New York City, visit New York City weather in December.

Compare New York City's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in New York City

As September arrives in New York City, the transition from the sweltering summer heat begins, inviting a refreshing shift in the weather. With average temperatures hovering around a comfortable 21°C (70°F) and a maximum heat peaking at 33°C (92°F), this month offers a delightful blend of warmth and cool breezy days, especially as evening temperatures dip closer to 9°C (49°F). Unlike the intense humidity typical of the summer months, September sees a more moderate humidity level of 68%, paired with occasional rainfall that amounts to about 92 mm over roughly nine days, keeping the city vibrant and lush. This makes September a unique time to explore the diverse offerings of NYC while enjoying the crispness of autumn on the horizon. For more insights into the weather patterns that define the city, visit New York City Climate.