September weather forecastHigh Island, TX
September
Weather in September
The first month of the autumn, September, is still a tropical month in High Island, Texas, with an average temperature varying between 86.4°F (30.2°C) and 73.8°F (23.2°C).Temperature
During September, High Island observes a subtle ascent to a still hot 86.4°F (30.2°C) from August's 91°F (32.8°C) in the average high-temperature. Throughout September, the average low-temperature records at a warm 73.8°F (23.2°C).Heat index
For most parts of September, the heat index is evaluated at a torrid 98.6°F (37°C). Adopt heightened safety measures, heat cramps and heat exhaustion may occur. Sustained activity might cause heatstroke.One should consider that heat index numbers are for shaded settings and light wind. Uninterrupted exposure to the sun may boost the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', quantifies the warmth felt when relative humidity is considered. An individual's perception of weather can be swayed by a variety of elements including metabolic differences, pregnancy status, and their level of physical exertion. It is noteworthy to mention that direct sunlight exposure can augment the felt temperature, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for babies and toddlers. Youngsters generally face more threats than adults given their lesser ability to sweat. Coupled with their larger skin surface relative to their small bodies and higher heat production due to their activities, they are more endangered.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. Under high air temperature and high humidity (high heat index) conditions, the body's ability to perspire is compromised, increasing the sensation of heat. Heat absorption that surpasses the body's shedding capability can lead to overheating and varying levels of dehydration.
Humidity
In High Island, the average relative humidity in September is 77%.Rainfall
The month with the most rainfall in High Island is September, when the rain falls for 17.6 days and typically aggregates up to 2.01" (51mm) of precipitation.Snowfall
January through November are months without snowfall.Daylight
In September, the average length of the day is 12h and 20min.On the first day of the month, sunrise is at 6:55 am and sunset at 7:39 pm. On the last day of September, sunrise is at 7:10 am and sunset at 7:03 pm CDT.
Sunshine
In High Island, the average sunshine in September is 9.3h.UV index
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 average individuals.Note: The maximum daily UV index of 6 during September translates into the following directions:
Persist with safeguards and heed sun safety doctrines. Keeping sunburn at bay is of prime importance. Minimize exposure to direct sunlight and seek shade from 10 a.m. to 4 p.m., when UV radiation is most intense, but remember that shade structures may not offer complete protection. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
High Island, TX
- Average high temperature in September: 86.4°F
The warmest month (with the highest average high temperature) is August (91°F).
The month with the lowest average high temperature is January (59.5°F).
- Average low temperature in September: 73.8°F
The month with the highest average low temperature is July (77.9°F).
The coldest month (with the lowest average low temperature) is January (46.9°F).
Average pressure in September
High Island, TX
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
High Island, TX
- Average wind speed in September: 6.6mph
The windiest month (with the highest average wind speed) is April (9.5mph).
The calmest months (with the lowest average wind speed) are August and September (6.6mph).
Average humidity in September
High Island, TX
- Average humidity in September: 77%
The month with the highest relative humidity is February (81%).
The month with the lowest relative humidity is October (73%).
Average rainfall in September
High Island, TX
- Average rainfall in September: 2.01"
The wettest month (with the highest rainfall) is September (2.01").
The driest months (with the least rainfall) are February and March (0.43").
Average rainfall days in September
High Island, TX
- Average rainfall days in September: 17.6 days
The month with the highest number of rainy days is September (17.6 days).
The month with the least rainy days is February (6.5 days).
Average snowfall in September
High Island, TX
- Average snowfall in September: 0"
The month with the highest snowfall is December (0.04").
The months with the least snowfall are January, February, March, April, May, June, July, August, September, October and November (0").
Average snowfall days in September
High Island, TX
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (0.2 days).
The months with the least snowfall days are March, April, May, June, July, August, October and November (0 days).
Average daylight in September /
Average sunshine in September
High Island, TX
- Average daylight in September: 12h and 18min
The month with the longest days is June (Average daylight: 14h and 0min).
The month with the shortest days is December (Average daylight: 10h and 18min).
- Average sunshine in September: 9h and 18min
The month with the most sunshine is August (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 0min).
Average sunshine days in September
High Island, TX
- Average sunshine days in September: 9.7 days
The month with the most sunshine days is January (21.3 days).
The month with the least sunshine days is August (9.3 days).
Average UV index in September
High Island, 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
High Island, TX
- Average cloud cover in September: 28
The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in September
High Island, 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).





