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
Jonestown's weather subtly changes with the onset of September, barely falling from a very hot 95.5°F (35.3°C) in August to a tropical 87.8°F (31°C). An average low-temperature of 69.8°F (21°C) is common during the nights of September.Heat index
During September, the heat index is calculated to be a torrid 98.6°F (37°C). Incorporate additional preventive steps, heat exhaustion and heat cramps are possible. Long-lasting activity may cause heatstroke.Take note of the fact that heat index values are based on shaded circumstances with light airflows. 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 'feels like', is a measure that combines air temperature and relative humidity into a single value that indicates how hot the weather feels. Factors encompassing physical activity, clothing, and metabolic differences have a role in shaping the individual's impression of temperature. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. An increase in relative humidity retards evaporation, subsequently reducing the body's heat removal rate and leading to a sensation of being overly warm. If the body retains more heat than it can expel, the increasing temperature can lead to heat-related conditions.
Humidity
In September, the average relative humidity is 67%.Rainfall
In September, the rain falls for 14.3 days. Throughout September, 3.03" (77mm) of precipitation is accumulated. In Jonestown, during the entire year, the rain falls for 137.4 days and collects up to 24.13" (613mm) of precipitation.Snowfall
March through December are months without snowfall.Daylight
The average length of the day in September is 12h and 20min.On the first day of September, sunrise is at 7:08 am and sunset at 7:54 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 7:17 pm CDT.
Sunshine
In Jonestown, Texas, the average sunshine in September is 8.3h.UV index
The average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for the average person.Note: In September, the maximum UV index of 6 transforms into these recommendations:
Deflect overexposure. Sun protection is a necessity. Avoid direct Sun exposure and seek shade from 10 a.m. to 4 p.m., the period of highest UV radiation. Remember, however, that not all shade structures offer full protection. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Jonestown, TX
- Average high temperature in September: 87.8°F
The warmest month (with the highest average high temperature) is August (95.5°F).
The month with the lowest average high temperature is January (58.8°F).
- Average low temperature in September: 69.8°F
The month with the highest average low temperature is August (74.8°F).
The coldest month (with the lowest average low temperature) is January (41.9°F).
Average pressure in September
Jonestown, TX
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The months with the lowest atmospheric pressure are May and June (29.91"Hg).
Average wind speed in September
Jonestown, TX
- Average wind speed in September: 6.3mph
The windiest month (with the highest average wind speed) is March (9.6mph).
The calmest month (with the lowest average wind speed) is September (6.3mph).
Average humidity in September
Jonestown, TX
- Average humidity in September: 67%
The month with the highest relative humidity is May (74%).
The month with the lowest relative humidity is August (59%).
Average rainfall in September
Jonestown, TX
- Average rainfall in September: 3.03"
The wettest month (with the highest rainfall) is May (4.02").
The driest month (with the least rainfall) is February (1.02").
Average rainfall days in September
Jonestown, TX
- Average rainfall days in September: 14.3 days
The month with the highest number of rainy days is May (15.4 days).
The month with the least rainy days is January (8.2 days).
Average snowfall in September
Jonestown, TX
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.24").
The months with the least snowfall are March, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in September
Jonestown, 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 March, April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Jonestown, 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 July (Average sunshine: 10h and 24min).
The months with the least sunshine are November and December (Average sunshine: 5h and 24min).
Average sunshine days in September
Jonestown, TX
- Average sunshine days in September: 13.1 days
The month with the most sunshine days is January (21.2 days).
The month with the least sunshine days is May (12.5 days).
Average UV index in September
Jonestown, TX
- Average UV index in September: 6
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 3).
Average cloud cover in September
Jonestown, TX
- Average cloud cover in September: 33
The months with the most cloud cover are March and May (Cloud cover 45).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in September
Jonestown, 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).
Jonestown, Texas, USA
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