September weather forecastGrapevine, TX
September
Weather in September
The first month of the autumn, September, is still a tropical month in Grapevine, Texas, with an average temperature ranging between max 87.8°F (31°C) and min 70.7°F (21.5°C).Temperature
With the commencement of September, Grapevine records a moderate temperature decline, with the average high easing from August's torrid 96.4°F (35.8°C) to a tropical 87.8°F (31°C). During September, Grapevine observes a consistent average nighttime temperature of 70.7°F (21.5°C).Heat index
During September, the heat index is calculated to be a very hot 95°F (35°C). Ensure heightened precautions, risk of heat cramps and heat exhaustion is significant. Sustained activity could provoke heatstroke.It is important to note that the heat index values are for shaded areas and light wind scenarios. Being under direct sunlight might amplify the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is the outcome of merging air's temperature and its humidity metrics. One's weather perception can be influenced by a range of factors including metabolic differences, being pregnant, and their level of physical activity. Remember, direct sunlight exposure can heighten the heat impact and might increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Children often fail to understand the importance of rest and rehydration. Thirst is a late manifestation of dehydration - hence, it is crucial to stay hydrated, especially during ongoing physical activities.
To cool down, the human body relies on perspiration, a process where excessive heat is eliminated as sweat evaporates. Heightened relative humidity interferes with the body's usual cooling mechanism by reducing evaporation, subsequently decreasing the body's cooling rate and increasing the sensation of heat. When body temperature rises due to excess heat gain beyond its removal capability, one might experience heat-related disorders.
Humidity
In September, the average relative humidity is 62%.Rainfall
In Grapevine, in September, it is raining for 10.5 days, with typically 0.55" (14mm) of accumulated precipitation. In Grapevine, during the entire year, the rain falls for 97.8 days and collects up to 9.29" (236mm) of precipitation.Snowfall
In Grapevine, snow does not fall in April through December.Daylight
In Grapevine, the average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 7:03 am and sunset at 7:52 pm. On the last day of September, sunrise is at 7:22 am and sunset at 7:13 pm CDT.
Sunshine
In Grapevine, the average sunshine in September is 8.5h.UV index
In September, the average daily maximum UV index is 6. A UV Index reading of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: An average UV index of 6 in September transforms into this advice:
Implement precautions and maintain sun safety methods. Avoidance of sunburn is demanded. Seek shade and limit direct Sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its peak, but be aware that not all shade structures provide complete sun protection. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Grapevine, TX
- Average high temperature in September: 87.8°F
The warmest month (with the highest average high temperature) is August (96.4°F).
The month with the lowest average high temperature is January (54.5°F).
- Average low temperature in September: 70.7°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 (38.8°F).
Average pressure in September
Grapevine, 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
Grapevine, TX
- Average wind speed in September: 6.7mph
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 (6.7mph).
Average humidity in September
Grapevine, TX
- Average humidity in September: 62%
The month with the highest relative humidity is May (71%).
The month with the lowest relative humidity is August (54%).
Average rainfall in September
Grapevine, TX
- Average rainfall in September: 0.55"
The wettest month (with the highest rainfall) is May (1.34").
The driest month (with the least rainfall) is February (0.39").
Average rainfall days in September
Grapevine, TX
- Average rainfall days in September: 10.5 days
The month with the highest number of rainy days is September (10.5 days).
The month with the least rainy days is January (4.5 days).
Average snowfall in September
Grapevine, TX
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.16").
The months with the least snowfall are April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Grapevine, TX
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.9 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
Grapevine, 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 month with the most sunshine is July (Average sunshine: 11h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in September
Grapevine, TX
- Average sunshine days in September: 16.8 days
The month with the most sunshine days is January (25.1 days).
The month with the least sunshine days is September (16.8 days).
Average UV index in September
Grapevine, TX
- Average UV index in September: 6
The months with the highest UV index are May, June, July and August (UV index 7).
The months with the lowest UV index are January and December (UV index 3).
Average cloud cover in September
Grapevine, TX
- Average cloud cover in September: 28
The month with the most cloud cover is March (Cloud cover 40).
The month with the least cloud cover is August (Cloud cover 19).
Average visibility in September
Grapevine, 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).
