Dallas
Texas, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Dallas, TX

Dallas, Texas, modern city skyscrapers viewed from above, just before sunset
Dallas, Texas, modern city skyscrapers viewed from above, just before sunset
September, the first month of the autumn, in Dallas, is still a hot month, with average temperature varying between 70.5°F (21.4°C) and 87.8°F (31°C).

Temperature

In Dallas, the average high-temperature slightly decreases, from a torrid 96.1°F (35.6°C) in August, to a hot 87.8°F (31°C). In Dallas, the average low-temperature is 70.5°F (21.4°C).

Heat index

In September, the average heat index is estimated at a sweltering 95.7°F (35.4°C). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'apparent temperature', 'real feel', or 'felt air temperature', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. This effect is subjective, depending on the activity and individual's heat perception influenced by various reasons (clothing, differences in body mass, height, and shape, pregnancy). Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. A higher relative humidity affects normal body cooling by reducing the evaporation rate, subsequently lowering the rate at which the body cools and increasing the perception of heat. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

The average relative humidity is 62%.

Rainfall

In Dallas, during September, the rain falls for 14.1 days and regularly aggregates up to 2.32" (59mm) of precipitation. In Dallas, during the entire year, the rain falls for 141.2 days and collects up to 30.12" (765mm) of precipitation.

Snowfall

March through October are months without snowfall in Dallas.

Daylight

The average length of the day in September is 12.4h.

Sunshine

The average sunshine in September is 8.6h.

UV index

In Dallas, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health vulnerability from the exposure to the Sun's UV rays for average individuals.
Note: In September, the average maximum UV index of 6 translate into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the temperature in September in Dallas?

In Dallas, Texas, in September, the average high-temperature is 87.8°F (31°C), and the average low-temperature is 70.5°F (21.4°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), that combines air temperature and relative humidity, in September is appraised at 95.7°F (35.4°C).

What is the average humidity in September in Dallas?

The average relative humidity in September is 62%.

How many days does it rain in September in Dallas?

In Dallas, in September, during 14.1 rainfall days, 2.32" (59mm) of precipitation is typically accumulated.

When it does not snow in Dallas?

March through October are months without snowfall in Dallas.

How many hours of daylight does Dallas have in September?

In Dallas, Texas, the average length of the day in September is 12.4h.

How long on average sun shines in September in Dallas?

The average sunshine in September in Dallas, Texas, is 8.6h.

How high is the UV index in September in Dallas?

The average daily maximum UV index in September in Dallas is 6. A UV Index of 6 to 7 symbolizes a high hazard to health from the exposure to the Sun's UV rays.
Average temperature in September - Dallas, TX
  • Average high temperature in September: 87.8°F

The warmest month (with the highest average high temperature) is August (96.1°F).
The month with the lowest average high temperature is January (54.3°F).

  • Average low temperature in September: 70.5°F

The month with the highest average low temperature is August (77.2°F).
The coldest month (with the lowest average low temperature) is January (39.2°F).

Average humidity in September - Dallas, TX
  • Average humidity in September: 62%

The month with the highest relative humidity is May (72%).
The month with the lowest relative humidity is August (55%).

Average rainfall in September - Dallas, TX
  • Average rainfall in September: 2.32"

The wettest month (with the highest rainfall) is May (4.13").
The driest month (with the lowest rainfall) is February (1.61").

Average rainfall days in September - Dallas, TX
  • Average rainfall days in September: 14.1 days

The month with the highest number of rainy days is May (15.8 days).
The month with the lowest number of rainy days is January (6.7 days).

Average snowfall in September - Dallas, TX
  • Average snowfall in September: 0"

The month with the highest snowfall is February (0.43").
Months with the lowest snowfall are March, April, May, June, July, August, September and October (0").

Average snowfall days in September - Dallas, TX
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (1.2 days).
Months with the lowest number of snowfall days are March, April, May, June, July, August, September and October (0 days).

Average daylight in September / Average sunshine in September - Dallas, TX
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.3h).
The month with shortest days is December (Average daylight: 10h).

  • Average sunshine in September: 8.6h

The month with most sunshine is August (Average sunshine: 11.1h).
The month with least sunshine is December (Average sunshine: 5.6h).

Average UV index in September - Dallas, TX
  • Average UV index in September: 6

Months with the highest UV index are May, June, July and August (UV index 7).
Months with the lowest UV index are January and December (UV index 3).