September weather forecast
Houston, DE

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Houston, Delaware, with an average temperature fluctuating between 76.1°F (24.5°C) and 64°F (17.8°C).

Temperature

A mild drop in Houston's average high-temperature is observed in September, transitioning from 81.5°F (27.5°C) in August to a still warm 76.1°F (24.5°C). The nighttime temperature in Houston, Delaware, during September, averages of 64°F (17.8°C).

Humidity

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

Rainfall

In Houston, Delaware, in September, during 13.5 rainfall days, 1.85" (47mm) of precipitation is typically accumulated. Throughout the year, there are 152.4 rainfall days, and 25.94" (659mm) of precipitation is accumulated.

Snowfall

April, June through October are months without snowfall.

Daylight

In September, the average length of the day is 12h and 26min.
On the first day of September, sunrise is at 6:31 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:45 pm EDT.

Sunshine

In Houston, the average sunshine in September is 9.4h.

UV index

In Houston, Delaware, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.
Note: A daily maximum UV index of 5 in September translates into the following instructions:
Make use of precautions - It is urged to ward off sun damage. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Updated: Aug 23, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

Houston in September has an average high-temperature of 76.1°F (24.5°C) and an average low-temperature of 64°F (17.8°C). The average heat index (a.k.a. 'apparent temperature', 'feels like'), which represents the influence of relative humidity on air temperature, in August is evaluated at 87.8°F (31°C).

What is the average humidity in September?

In September, the average relative humidity is 79%.

How much does it rain in September?

In Houston, in September, during 13.5 rainfall days, 1.85" (47mm) of precipitation is typically accumulated.

When it does not snow?

In Houston, snow does not fall in April, June through October.

What is the average length of the day in September?

The average day length in September is 12h and 26min.

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:31 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:45 pm EDT.

How many hours of sunshine does Houston have in September?

In Houston, the average sunshine duration in September is 9.4h.

What is the UV index intensity in September?

In Houston, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium health risk 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
Houston, DE

Average temperature in September - Houston, DE
  • Average high temperature in September: 76.1°F

The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is January (40.6°F).

  • Average low temperature in September: 64°F

The month with the highest average low temperature is July (70.7°F).
The coldest month (with the lowest average low temperature) is January (29.7°F).

Average pressure in September
Houston, DE

Average pressure in September - Houston, DE
  • Average pressure in September: 30.04"Hg

The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

Average wind speed in September
Houston, DE

Average wind speed in September - Houston, DE
  • Average wind speed in September: 7.8mph

The windiest month (with the highest average wind speed) is February (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).

Average humidity in September
Houston, DE

Average humidity in September - Houston, DE
  • Average humidity in September: 79%

The month with the highest relative humidity is May (80%).
The months with the lowest relative humidity are January and November (74%).

Average rainfall in September
Houston, DE

Average rainfall in September - Houston, DE
  • Average rainfall in September: 1.85"

The wettest month (with the highest rainfall) is August (3.07").
The driest month (with the least rainfall) is January (1.5").

Average rainfall days in September
Houston, DE

Average rainfall days in September - Houston, DE
  • Average rainfall days in September: 13.5 days

The month with the highest number of rainy days is July (17.3 days).
The month with the least rainy days is January (8.4 days).

Average snowfall in September
Houston, DE

Average snowfall in September - Houston, DE
  • Average snowfall in September: 0"

The month with the highest snowfall is January (1.22").
The months with the least snowfall are April, June, July, August, September and October (0").

Average snowfall days in September
Houston, DE

Average snowfall days in September - Houston, DE
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (3.3 days).
The months with the least snowfall days are April, June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Houston, DE

Average daylight in September / Average sunshine in September - Houston, DE
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in September: 9h and 2min

The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 0min).

Average sunshine days in September
Houston, DE

Average sunshine days in September - Houston, DE
  • Average sunshine days in September: 14.7 days

The month with the most sunshine days is January (19.6 days).
The month with the least sunshine days is July (11.6 days).

Average UV index in September
Houston, DE

Average UV index in September - Houston, DE
  • Average UV index in September: 5

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 and December (UV index 2).

Average cloud cover in September
Houston, DE

Average cloud cover in September - Houston, DE
  • Average cloud cover in September: 32

The months with the most cloud cover are February and March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 27).

Average visibility in September
Houston, DE

Average visibility in September - Houston, DE
  • 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).

Houston, Delaware, USA

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