September weather forecast
Katonah, NY

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Weather in September

The first month of the autumn, September, is still a warm month in Katonah, New York, with an average temperature fluctuating between 58.1°F (14.5°C) and 73.9°F (23.3°C).

Temperature

The onset of September brings a small shift in high-temperatures, falling from a moderately hot 81.1°F (27.3°C) in August to a still warm 73.9°F (23.3°C). An average nighttime temperature of 58.1°F (14.5°C) is witnessed throughout September.

Humidity

In September, the average relative humidity is 76%.

Rainfall

In Katonah, in September, during 12.2 rainfall days, 1.5" (38mm) of precipitation is typically accumulated. Throughout the year, in Katonah, there are 144.2 rainfall days, and 22.32" (567mm) of precipitation is accumulated.

Snowfall

In Katonah, snow does not fall in June through September.

Daylight

In September, the average length of the day is 12h and 28min.
On the first day of the month, sunrise is at 6:21 am and sunset at 7:27 pm. On the last day of September, sunrise is at 6:51 am and sunset at 6:37 pm EDT.

Sunshine

In Katonah, the average sunshine in September is 8.9h.

UV index

The average daily maximum UV index in September in Katonah is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the average person.
Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Be mindful. Those with pale skin might receive burns in fewer than 30 minutes. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Updated: Aug 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

September temperatures vary between a high-temperature of 73.9°F (23.3°C) and a low-temperature of 58.1°F (14.5°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which combines relative humidity and air temperature, in August is estimated at 86°F (30°C).

What is the average humidity in September?

In September, the average relative humidity is 76%.

How many days does it rain in September?

In Katonah, in September, during 12.2 rainfall days, 1.5" (38mm) of precipitation is typically accumulated.

When it does not snow in Katonah?

In Katonah, snow does not fall in June through September.

Does it snow in September?

In Katonah, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September?

In September, the average day length is 12h and 28min.

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:21 am and sunset at 7:27 pm. On the last day of the month, sunrise is at 6:51 am and sunset at 6:37 pm EDT.

How many hours of sunshine does Katonah have in September?

In September, the average sunshine duration is 8.9h.

What is the UV index intensity in September in Katonah?

In Katonah, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health risk from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Katonah, NY

Average temperature in September - Katonah, NY
  • Average high temperature in September: 73.9°F

The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is January (34.5°F).

  • Average low temperature in September: 58.1°F

The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (23.2°F).

Average pressure in September
Katonah, NY

Average pressure in September - Katonah, NY
  • Average pressure in September: 30.06"Hg

The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in September
Katonah, NY

Average wind speed in September - Katonah, NY
  • Average wind speed in September: 6mph

The windiest month (with the highest average wind speed) is January (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).

Average humidity in September
Katonah, NY

Average humidity in September - Katonah, NY
  • Average humidity in September: 76%

The month with the highest relative humidity is February (78%).
The month with the lowest relative humidity is April (72%).

Average rainfall in September
Katonah, NY

Average rainfall in September - Katonah, NY
  • Average rainfall in September: 1.5"

The wettest month (with the highest rainfall) is July (2.68").
The driest month (with the least rainfall) is February (1.18").

Average rainfall days in September
Katonah, NY

Average rainfall days in September - Katonah, NY
  • Average rainfall days in September: 12.2 days

The month with the highest number of rainy days is July (16.5 days).
The month with the least rainy days is January (6.8 days).

Average snowfall in September
Katonah, NY

Average snowfall in September - Katonah, NY
  • Average snowfall in September: 0"

The month with the highest snowfall is March (2.95").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Katonah, NY

Average snowfall days in September - Katonah, NY
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (6.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Katonah, NY

Average daylight in September / Average sunshine in September - Katonah, NY
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in September: 8h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

Average sunshine days in September
Katonah, NY

Average sunshine days in September - Katonah, NY
  • Average sunshine days in September: 15.7 days

The month with the most sunshine days is November (20.3 days).
The month with the least sunshine days is June (12.1 days).

Average UV index in September
Katonah, NY

Average UV index in September - Katonah, NY
  • Average UV index in September: 4

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).

Average cloud cover in September
Katonah, NY

Average cloud cover in September - Katonah, NY
  • Average cloud cover in September: 34

The month with the most cloud cover is February (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 30).

Average visibility in September
Katonah, NY

Average visibility in September - Katonah, NY
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Katonah, New York, USA

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