September weather forecast
Chatham, PA

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Weather in September

September, the first month of the autumn in Chatham, is also a moderately hot month, with an average temperature fluctuating between 75°F (23.9°C) and 58.8°F (14.9°C).

Temperature

September signifies a minor drop in average high-temperature, transitioning from 81.9°F (27.7°C) in August to a still moderately hot 75°F (23.9°C). An average temperature of 58.8°F (14.9°C) is recorded during the nights in September.

Humidity

February, May, September, October and December, with an average relative humidity of 79%, are the most humid months in Chatham.

Rainfall

The months with the least rainfall are January, September and November Rain falls for 10.8 days and accumulates 0.87" (22mm) of rain.

Snowfall

June through October are months without snowfall.

Daylight

In Chatham, the average length of the day in September is 12h and 26min.
On the first day of September, sunrise is at 6:31 am and sunset at 7:34 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 6:46 pm EDT.

Sunshine

In September, the average sunshine is 8.9h.

UV index

In September, the average daily maximum UV index in Chatham is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the average person.
Note: In September, a regular UV index of 4 translates into these guidelines:
Undertake precautions - Guarding against sun damage is counselled. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.

Frequently asked questions

What is the temperature in September?

In September, in Chatham, the average high-temperature is 75°F (23.9°C), and the average low-temperature is 58.8°F (14.9°C). In August, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which represents the influence of relative humidity on air temperature, is appraised at 87.8°F (31°C).

What are the most humid months?

The months with the highest humidity are February, May, September, October and December, with an average relative humidity of 79%.

What is the average humidity in September?

In Chatham, Pennsylvania, the average relative humidity in September is 79%.

What is the driest month?

The months with the least rainfall are January, September and November Rain falls for 10.8 days and accumulates 0.87" (22mm) of rain.

How many days does it rain in September?

In Chatham, in September, it is raining for 10.8 days, with typically 0.87" (22mm) of accumulated precipitation.

When it does not snow?

In Chatham, snow does not fall in June through October.

How many hours of daylight does Chatham have in September?

In Chatham, the average day length in September is 12h and 26min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:31 am and sunset at 7:34 pm. On the last day of the month, in Chatham, sunrise is at 6:59 am and sunset at 6:46 pm EDT.

How long on average sun shines in September?

The average sunshine duration in September in Chatham is 8.9h.

What is the UV index reading in September?

The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health threat from unsafe 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
Chatham, PA

Average temperature in September - Chatham, PA
  • Average high temperature in September: 75°F

The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (36.9°F).

  • Average low temperature in September: 58.8°F

The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (24.6°F).

Average pressure in September
Chatham, PA

Average pressure in September - Chatham, PA
  • Average pressure in September: 30.06"Hg

The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

Average wind speed in September
Chatham, PA

Average wind speed in September - Chatham, PA
  • Average wind speed in September: 5.8mph

The windiest months (with the highest average wind speed) are February and March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).

Average humidity in September
Chatham, PA

Average humidity in September - Chatham, PA
  • Average humidity in September: 79%

The months with the highest relative humidity are February, May, September, October and December (79%).
The months with the lowest relative humidity are March and April (75%).

Average rainfall in September
Chatham, PA

Average rainfall in September - Chatham, PA
  • Average rainfall in September: 0.87"

The wettest month (with the highest rainfall) is August (1.93").
The driest months (with the least rainfall) are January, September and November (0.87").

Average rainfall days in September
Chatham, PA

Average rainfall days in September - Chatham, PA
  • Average rainfall days in September: 10.8 days

The month with the highest number of rainy days is July (14.9 days).
The month with the least rainy days is January (5.9 days).

Average snowfall in September
Chatham, PA

Average snowfall in September - Chatham, PA
  • Average snowfall in September: 0"

The month with the highest snowfall is March (1.26").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in September
Chatham, PA

Average snowfall days in September - Chatham, PA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (5.1 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Chatham, PA

Average daylight in September / Average sunshine in September - Chatham, PA
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).

  • Average sunshine in September: 8h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

Average sunshine days in September
Chatham, PA

Average sunshine days in September - Chatham, PA
  • Average sunshine days in September: 17.6 days

The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is July (12.9 days).

Average UV index in September
Chatham, PA

Average UV index in September - Chatham, PA
  • Average UV index in September: 4

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

Average cloud cover in September
Chatham, PA

Average cloud cover in September - Chatham, PA
  • Average cloud cover in September: 37

The months with the most cloud cover are February and March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 30).

Average visibility in September
Chatham, PA

Average visibility in September - Chatham, PA
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).

Chatham, Pennsylvania, USA

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