September weather forecastLewisville, TX
September
Weather in September
September ushers in autumn in the city of Lewisville, bringing milder temperatures than the summer highs of August. Rainfall increases slightly to 2.64" (67mm), compensating for the reduced humidity through the later moments of summer. The winds continue their downward trajectory, maintaining a serene atmosphere across the city. The arrival of October brings a further drop in temperatures, making for a comfortable autumn atmosphere.Temperature
The move into September in Lewisville indicates a slight reduction in the average high-temperature, down from August's sweltering 96.3°F (35.7°C) to a tropical 88°F (31.1°C). Lewisville experiences an average low-temperature of 70.7°F (21.5°C) in the month of September.Heat index
In September, the average heat index is computed to be a torrid 95°F (35°C). Apply extra caution, heat cramps and heat exhaustion could happen. Heatstroke might occur with long-duration activity.Take into consideration that the heat index values are calculated for shade and light wind conditions. The heat index may scale up by 15 Fahrenheit (8 Celsius) degrees with direct sun exposure.
Note: The heat index, also known as 'real feel' or 'feels like', joins air temperature with relative humidity to produce a temperature perception for humans. One's perception of weather can be shaped by other factors, involving metabolic differences, pregnancy, and physical exertion. When you're directly under the sun's rays, remember that the heat index may surge by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical to babies and toddlers. Young ones often do not realize the necessity to rest and replenish their fluids. Thirst is a delayed indication of dehydration - keeping hydrated, particularly in prolonged physical activity, is crucial.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. Greater relative humidity lessens the rate of evaporation, thus decreasing the body's heat dispersal, which gives rise to a sensation of overheating. Increasing body temperatures can be a precursor to dehydration if the body can't shed the extra heat.
Humidity
The average relative humidity in September is 61%.Rainfall
In Lewisville, in September, it is raining for 14 days, with typically 2.64" (67mm) of accumulated precipitation. In Lewisville, during the entire year, the rain falls for 132.1 days and collects up to 29.09" (739mm) of precipitation.Snowfall
In Lewisville, Texas, snow does not fall in April through October.Daylight
The average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 7:02 am and sunset at 7:52 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 7:13 pm CDT.
Sunshine
The average sunshine in September is 8.5h.UV index
In Lewisville, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation for the average person.Note: In September, the maximum UV index of 6 suggests these recommendations:
Fend off overexposure. Sun protection is vital. The hours from 10 a.m. to 4 p.m. have the most intense UV radiation. As much as possible, limit direct sun exposure during this period. 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
Average temperature in September
Lewisville, TX
- Average high temperature in September: 88°F
The warmest month (with the highest average high temperature) is August (96.3°F).
The month with the lowest average high temperature is January (54.1°F).
- Average low temperature in September: 70.7°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 (38.5°F).
Average pressure in September
Lewisville, TX
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Lewisville, TX
- Average wind speed in September: 6.8mph
The windiest months (with the highest average wind speed) are March and April (10.1mph).
The calmest month (with the lowest average wind speed) is September (6.8mph).
Average humidity in September
Lewisville, TX
- Average humidity in September: 61%
The month with the highest relative humidity is May (71%).
The month with the lowest relative humidity is August (53%).
Average rainfall in September
Lewisville, TX
- Average rainfall in September: 2.64"
The wettest month (with the highest rainfall) is October (3.74").
The driest months (with the least rainfall) are January and February (1.57").
Average rainfall days in September
Lewisville, TX
- Average rainfall days in September: 14 days
The month with the highest number of rainy days is May (14.3 days).
The month with the least rainy days is January (6.6 days).
Average snowfall in September
Lewisville, TX
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.63").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Lewisville, TX
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.1 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Lewisville, TX
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 8h and 30min
The months with the most sunshine are July and August (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 36min).
Average sunshine days in September
Lewisville, TX
- Average sunshine days in September: 14.9 days
The month with the most sunshine days is January (23.2 days).
The month with the least sunshine days is September (14.9 days).
Average UV index in September
Lewisville, 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
Lewisville, TX
- Average cloud cover in September: 29
The month with the most cloud cover is March (Cloud cover 40).
The month with the least cloud cover is August (Cloud cover 20).
Average visibility in September
Lewisville, 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).
