Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The move into September indicates a slight reduction in the average high-temperature, down from August's tropical 93.6°F (34.2°C) to a moderately hot 84.7°F (29.3°C). McLean experiences an average low-temperature of 65.1°F (18.4°C) in the month of September.Heat index
The heat index value for September is evaluated at a hot 87.8°F (31°C). Unrelenting activity during exposure could cause fatigue and potentially lead to heat cramps.Always consider that heat index estimations are for light winds and places in the shade. Heat index values can rise by 15 Fahrenheit (8 Celsius) degrees when in direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', shows a temperature sensation when both heat and moisture conditions are combined. Elements such as metabolic variations, pregnancy, and physical exertion can shape one's weather perception. When in direct sunlight, one should be cautious as it can raise the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular significance for children. Typically, young kids are at a higher risk than adults since they sweat less. Also, the larger skin surface in proportion to their small bodies and the heightened heat production due to their active nature adds to their vulnerability.
Humidity
September is the most humid month in McLean, with an average relative humidity of 57%.Rainfall
In McLean, in September, it is raining for 10.6 days, with typically 1.93" (49mm) of accumulated precipitation. Throughout the year, there are 93.9 rainfall days, and 17.17" (436mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall.Daylight
In September, the average length of the day in McLean, Texas, is 12h and 23min.On the first day of the month, sunrise is at 7:15 am and sunset at 8:08 pm. On the last day of September, sunrise is at 7:37 am and sunset at 7:27 pm CDT.
Sunshine
In September, the average sunshine is 9.1h.UV index
In McLean, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the average person.Note: A typical high UV index of 5 in September suggests the following recommendations:
Take necessary precautions - Suggestions to elude sunburn are provided. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot during September?
What is the most humid month?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
McLean, TX
- Average high temperature in September: 84.7°F
The warmest month (with the highest average high temperature) is July (94.1°F).
The month with the lowest average high temperature is December (50°F).
- Average low temperature in September: 65.1°F
The month with the highest average low temperature is July (73°F).
The coldest month (with the lowest average low temperature) is January (32°F).
Average pressure in September
McLean, TX
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
McLean, TX
- Average wind speed in September: 10.8mph
The windiest month (with the highest average wind speed) is April (13.9mph).
The calmest month (with the lowest average wind speed) is August (10.1mph).
Average humidity in September
McLean, TX
- Average humidity in September: 57%
The month with the highest relative humidity is September (57%).
The month with the lowest relative humidity is August (49%).
Average rainfall in September
McLean, TX
- Average rainfall in September: 1.93"
The wettest month (with the highest rainfall) is May (2.56").
The driest months (with the least rainfall) are February and November (0.59").
Average rainfall days in September
McLean, TX
- Average rainfall days in September: 10.6 days
The months with the highest number of rainy days are July and August (11.3 days).
The month with the least rainy days is January (3 days).
Average snowfall in September
McLean, TX
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.93").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
McLean, TX
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
McLean, TX
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is June (Average sunshine: 11h and 30min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in September
McLean, TX
- Average sunshine days in September: 16.4 days
The month with the most sunshine days is January (25.8 days).
The month with the least sunshine days is September (16.4 days).
Average UV index in September
McLean, TX
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 2).
Average cloud cover in September
McLean, TX
- Average cloud cover in September: 22
The month with the most cloud cover is April (Cloud cover 26).
The month with the least cloud cover is August (Cloud cover 16).
Average visibility in September
McLean, TX
- 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).
McLean, Texas, USA
Weather forecast for your location
2. Allow the app to use your location