September weather forecast
Tomball, TX

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Weather in September

September, the first month of the autumn in Tomball, is still a tropical month, with temperature in the range of an average high of 89.6°F (32°C) and an average low of 72.1°F (22.3°C).

Temperature

In the transition to September, Tomball observes a minor drop in the average high-temperature, shifting from a very hot 96.1°F (35.6°C) in August to a tropical 89.6°F (32°C). During September, Tomball experiences an average low-temperature of 72.1°F (22.3°C) at night.

Heat index

During September, the heat index is calculated to be a blisteringly hot 105.8°F (41°C). Adopt extra safety steps, risk of heat exhaustion and heat cramps is notable. Sustained activity might cause heatstroke.
Keep in mind the heat index values are meant for areas in shade and with light wind. When exposed to the direct sun, the heat index may augment by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', integrates the air's temperature and its humidity to showcase the felt temperature by people. Factors encompassing physical activity, clothing, and metabolic differences have a role in shaping the individual's impression of temperature. Being aware that direct sunlight can impact the felt heat might mean an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Young individuals are typically more threatened than adults due to their reduced perspiration. Also, the larger skin surface proportionate to their small bodies and the increased heat from their activities magnify their risk.
Through perspiration, the body has a natural mechanism to eliminate excessive heat via sweat evaporation. Elevated relative humidity disrupts typical body cooling by reducing the evaporation rate, consequently decreasing the body's cooling rate and enhancing the feeling of heat. When the body's heat gain surpasses its removal capacity, body temperature starts to climb, leading to potential heat-related ailments.

Humidity

The average relative humidity in September is 72%.

Rainfall

In Tomball, in September, during 18.8 rainfall days, 3.62" (92mm) of precipitation is typically accumulated. Throughout the year, in Tomball, there are 175.4 rainfall days, and 34.57" (878mm) of precipitation is accumulated.

Snowfall

In Tomball, snow does not fall in February through November.

Daylight

In September, the average length of the day is 12h and 20min.
On the first day of September, sunrise is at 6:59 am and sunset at 7:44 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 7:08 pm CDT.

Sunshine

In September, the average sunshine in Tomball, Texas, is 8.3h.

UV index

In September, the average daily maximum UV index is 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for the ordinary person.
Note: A daily high UV index of 6 in September leads to these guidelines:
Steer clear of overexposure. Fair-skinned individuals can be scorched in less than 20 minutes. Limit direct sun exposure and seek shade between 10 a.m. and 4 p.m., the time of the most intense UV radiation, noting that shade structures may not provide total sun protection. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How hot does it get in Tomball in September?

September temperatures vary between a high-temperature of 89.6°F (32°C) and a low-temperature of 72.1°F (22.3°C). The average heat index (a.k.a. 'real feel', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in September is calculated to be 105.8°F (41°C).

What is the average humidity in September in Tomball?

The average relative humidity in September is 72%.

How many days does it rain in September in Tomball?

In Tomball, in September, it is raining for 18.8 days, with typically 3.62" (92mm) of accumulated precipitation.

When it does not snow in Tomball?

February through November are months without snowfall in Tomball.

What is the average length of the day in September in Tomball?

The average day length in September is 12h and 20min.

When is the sunrise / sunset in September in Tomball?

On the first day of September, sunrise is at 6:59 am and sunset at 7:44 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 7:08 pm CDT.

How many hours of sunshine does Tomball have in September?

In Tomball, the average sunshine duration in September is 8.3h.

How high is the UV index in September in Tomball?

In Tomball, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health vulnerability 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
Tomball, TX

Average temperature in September - Tomball, TX
  • Average high temperature in September: 89.6°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 (60.4°F).

  • Average low temperature in September: 72.1°F

The month with the highest average low temperature is August (76.8°F).
The coldest month (with the lowest average low temperature) is January (44.2°F).

Average pressure in September
Tomball, TX

Average pressure in September - Tomball, TX
  • Average pressure in September: 29.96"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in September
Tomball, TX

Average wind speed in September - Tomball, TX
  • Average wind speed in September: 5.6mph

The windiest month (with the highest average wind speed) is April (8mph).
The calmest month (with the lowest average wind speed) is September (5.6mph).

Average humidity in September
Tomball, TX

Average humidity in September - Tomball, TX
  • Average humidity in September: 72%

The month with the highest relative humidity is February (78%).
The month with the lowest relative humidity is August (67%).

Average rainfall in September
Tomball, TX

Average rainfall in September - Tomball, TX
  • Average rainfall in September: 3.62"

The wettest month (with the highest rainfall) is May (4.72").
The driest month (with the least rainfall) is November (1.97").

Average rainfall days in September
Tomball, TX

Average rainfall days in September - Tomball, TX
  • Average rainfall days in September: 18.8 days

The month with the highest number of rainy days is September (18.8 days).
The month with the least rainy days is January (11.7 days).

Average snowfall in September
Tomball, TX

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

The month with the highest snowfall is January (0.12").
The months with the least snowfall are February, March, April, May, June, July, August, September, October and November (0").

Average snowfall days in September
Tomball, TX

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

The month with the highest number of snowfall days is January (0.3 days).
The months with the least snowfall days are February, March, April, May, June, July, August, September, October and November (0 days).

Average daylight in September /
Average sunshine in September
Tomball, TX

Average daylight in September / Average sunshine in September - Tomball, TX
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 6min).
The month with the shortest days is December (Average daylight: 10h and 12min).

  • Average sunshine in September: 8h and 2min

The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is December (Average sunshine: 4h and 48min).

Average sunshine days in September
Tomball, TX

Average sunshine days in September - Tomball, TX
  • Average sunshine days in September: 9.2 days

The month with the most sunshine days is October (17.1 days).
The month with the least sunshine days is September (9.2 days).

Average UV index in September
Tomball, TX

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

The months with the highest UV index are May, June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).

Average cloud cover in September
Tomball, TX

Average cloud cover in September - Tomball, TX
  • Average cloud cover in September: 35

The month with the most cloud cover is February (Cloud cover 53).
The month with the least cloud cover is August (Cloud cover 31).

Average visibility in September
Tomball, TX

Average visibility in September - Tomball, TX
  • Average visibility in September: 6mi

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

Tomball, Texas, USA

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