September weather forecast
Lebanon, CT

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Weather in September

September, the first month of the autumn in Lebanon, is still a pleasant month, with an average temperature fluctuating between 73.2°F (22.9°C) and 55.4°F (13°C).

Temperature

Transitioning from August to September involves a subtle drop in average high-temperatures, descending from a moderately hot 80.2°F (26.8°C) to an agreeable 73.2°F (22.9°C). During September, Lebanon observes a consistent average nighttime temperature of 55.4°F (13°C).

Humidity

In Lebanon, the average relative humidity in September is 78%.

Rainfall

September is the month with the least rainfall. Rain falls for 13.5 days and accumulates 1.73" (44mm) of precipitation.

Snowfall

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

Daylight

In Lebanon, the average length of the day in September is 12h and 28min.
On the first day of September, sunrise is at 6:15 am and sunset at 7:21 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:31 pm EDT.

Sunshine

In Lebanon, the average sunshine in September is 8.6h.

UV index

In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: A typical high UV index of 4 in September suggests the following recommendations:
Preventative actions are necessary - Recommendations to ward off sunburn are given. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Updated: Jun 18, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September?

In Lebanon, 73.2°F (22.9°C) is the average high-temperature and 55.4°F (13°C) is the average low-temperature during September. In July, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which represents the influence of relative humidity on air temperature, is evaluated at 87.8°F (31°C).

What is the average humidity in September?

In Lebanon, the average relative humidity in September is 78%.

What is the driest month?

September is the month with the least rainfall. Rain falls for 13.5 days and accumulates 1.73" (44mm) of precipitation.

How many days does it rain in September?

In September, the rain falls for 13.5 days. Throughout September, 1.73" (44mm) of precipitation is accumulated.

When it does not snow?

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

What is the average length of the day in September?

The average day length in September is 12h and 28min.

What time are sunrise and sunset in September in Lebanon?

In September, on the first day of the month, sunrise is at 6:15 am and sunset at 7:21 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:31 pm EDT.

How long on average sun shines in September?

The average sunshine duration in September is 8.6h.

How high is the UV index in September?

In Lebanon, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium hazard to health 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
Lebanon, CT

Average temperature in September - Lebanon, CT
  • Average high temperature in September: 73.2°F

The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (33.4°F).

  • Average low temperature in September: 55.4°F

The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).

Average pressure in September
Lebanon, CT

Average pressure in September - Lebanon, CT
  • Average pressure in September: 30.05"Hg

The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in September
Lebanon, CT

Average wind speed in September - Lebanon, CT
  • Average wind speed in September: 6.2mph

The windiest months (with the highest average wind speed) are January and March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).

Average humidity in September
Lebanon, CT

Average humidity in September - Lebanon, CT
  • Average humidity in September: 78%

The months with the highest relative humidity are February and October (79%).
The month with the lowest relative humidity is April (72%).

Average rainfall in September
Lebanon, CT

Average rainfall in September - Lebanon, CT
  • Average rainfall in September: 1.73"

The wettest month (with the highest rainfall) is December (3.46").
The driest month (with the least rainfall) is September (1.73").

Average rainfall days in September
Lebanon, CT

Average rainfall days in September - Lebanon, CT
  • Average rainfall days in September: 13.5 days

The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (9.1 days).

Average snowfall in September
Lebanon, CT

Average snowfall in September - Lebanon, CT
  • Average snowfall in September: 0"

The month with the highest snowfall is March (4.41").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in September
Lebanon, CT

Average snowfall days in September - Lebanon, CT
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (8.3 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Lebanon, CT

Average daylight in September / Average sunshine in September - Lebanon, CT
  • 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 12min).

  • Average sunshine in September: 8h and 4min

The month with the most sunshine is August (Average sunshine: 10h and 18min).
The month with the least sunshine is December (Average sunshine: 4h and 42min).

Average sunshine days in September
Lebanon, CT

Average sunshine days in September - Lebanon, CT
  • Average sunshine days in September: 14.6 days

The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is June (10.8 days).

Average UV index in September
Lebanon, CT

Average UV index in September - Lebanon, CT
  • 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
Lebanon, CT

Average cloud cover in September - Lebanon, CT
  • Average cloud cover in September: 37

The months with the most cloud cover are February, March, May and December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 33).

Average visibility in September
Lebanon, CT

Average visibility in September - Lebanon, CT
  • Average visibility in September: 5mi

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

Lebanon, Connecticut, USA

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