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 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
Transition into September subtly marks a drop in the average high-temperature, moderately moving from a very hot 100°F (37.8°C) in August to a hot 93°F (33.9°C). San Isidro records a consistent low-temperature of 77°F (25°C) during September nights.Heat index
Throughout September, the heat index is estimated at an extremely hot 109.4°F (43°C). Warning: Heat cramps and heat exhaustion are anticipated. Heatstroke is a risk with ongoing activity.When referencing the heat index, its values are suitable for shady environments and light breezes. Uninterrupted exposure to the sun may boost the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', combines air temperature and relative humidity to represent a human perceived temperature equivalent. One's perception of weather can be shaped by other factors, involving metabolic differences, pregnancy, and physical exertion. Direct sun exposure is noteworthy in its ability to escalate the felt temperature, potentially adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are particularly important for children. Youngsters are usually more at risk than adults, considering they sweat less. Additionally, their high skin surface area compared to their little bodies and their high heat production due to activity increases their risk.
Perspiration, which is the evaporation of sweat, is a primary way the human body manages and dispels excessive warmth. When air moisture content is high, the cooling process through evaporation is not as efficient, leading to an ineffective body cooling process and a feeling of overheating. Rising body temperatures due to excess heat retention could signify impending heat disorders.
Humidity
The average relative humidity in September is 62%.Rainfall
September is the month with the most rainfall. Rain falls for 15.3 days and accumulates 2.56" (65mm) of precipitation.Snowfall
March through December are months without snowfall.Daylight
In September, the average length of the day is 12h and 18min.On the first day of the month, sunrise is at 7:13 am and sunset at 7:53 pm. On the last day of September, in San Isidro, sunrise is at 7:26 am and sunset at 7:20 pm CDT.
Sunshine
In San Isidro, the average sunshine in September is 8.6h.UV index
In San Isidro, the average daily maximum UV index in September is 7. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: In September, a daily maximum UV index of 7 leads to the following instructions:
Adhere to precautions and respect sun safety doctrines. Avoiding sunburn is vital. Limit your exposure to the sun's UV radiation, which is strongest between 10 a.m. and 4 p.m., and note that parasols or canopies may not provide full sun protection. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Frequently asked questions
How hot is it in San Isidro in September?
What is the average humidity in September in San Isidro?
What is the rainiest month in San Isidro?
How much does it rain in San Isidro in September?
When it does not snow in San Isidro?
How many hours of daylight does San Isidro have in September?
What time are sunrise and sunset in September in San Isidro?
How long on average sun shines in September in San Isidro?
What is the UV index intensity in September in San Isidro?
Average temperature in September
San Isidro, TX
- Average high temperature in September: 93°F
The warmest month (with the highest average high temperature) is August (100°F).
The month with the lowest average high temperature is January (69.8°F).
- Average low temperature in September: 77°F
The month with the highest average low temperature is August (80.1°F).
The coldest month (with the lowest average low temperature) is January (52.7°F).
Average pressure in September
San Isidro, TX
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The months with the lowest atmospheric pressure are May and June (29.87"Hg).
Average wind speed in September
San Isidro, TX
- Average wind speed in September: 9.9mph
The windiest month (with the highest average wind speed) is July (13.9mph).
The calmest month (with the lowest average wind speed) is December (9.2mph).
Average humidity in September
San Isidro, TX
- Average humidity in September: 62%
The month with the highest relative humidity is December (65%).
The month with the lowest relative humidity is August (53%).
Average rainfall in September
San Isidro, TX
- Average rainfall in September: 2.56"
The wettest month (with the highest rainfall) is September (2.56").
The driest month (with the least rainfall) is February (0.47").
Average rainfall days in September
San Isidro, TX
- Average rainfall days in September: 15.3 days
The month with the highest number of rainy days is September (15.3 days).
The month with the least rainy days is February (5.8 days).
Average snowfall days in September
San Isidro, TX
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (0.1 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
San Isidro, TX
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 13h and 48min).
The month with the shortest days is December (Average daylight: 10h and 30min).
- Average sunshine in September: 8h and 4min
The months with the most sunshine are June and July (Average sunshine: 11h and 18min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in September
San Isidro, TX
- Average sunshine days in September: 12.9 days
The months with the most sunshine days are July and August (22.6 days).
The month with the least sunshine days is September (12.9 days).
Average UV index in September
San Isidro, TX
- Average UV index in September: 7
The months with the highest UV index are July and August (UV index 8).
The month with the lowest UV index is December (UV index 4).
Average cloud cover in September
San Isidro, TX
- Average cloud cover in September: 30
The month with the most cloud cover is December (Cloud cover 36).
The month with the least cloud cover is August (Cloud cover 16).
Average visibility in September
San Isidro, 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).
San Isidro, Texas, USA
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