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 sea temperature 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
Galveston's September average high-temperature settles at a warm 84.2°F (29°C), showing a near match with the preceding month. The September average low temperature, marginally lower than the daytime high, records at a still moderately hot 78.4°F (25.8°C).Heat index
In September, the heat index is calculated to be a tropical 93.2°F (34°C). Special measures are necessary to avoid heat cramps and heat exhaustion. Persistent activity could result in heatstroke.Heat index data is primarily for areas with shade and subjected to light winds. A rise of up to 15 Fahrenheit (8 Celsius) degrees in the heat index could result from direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. Physical activity, clothing, and metabolic variations are additional factors that impact an individual's perception of temperature. Considering the impact of direct sunlight, it's possible for the heat index to surge by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
Humidity
In Galveston, the average relative humidity in September is 75%.Rainfall
September is the month with the most rainfall. Rain falls for 19.9 days and accumulates 4.29" (109mm) of precipitation.Snowfall
March through December are months without snowfall.Ocean temperature
In September, the average ocean temperature is 83.8°F (28.8°C).Note: For swimming, diving, and enjoying other water activities, the range of 77°F (25°C) to 84.2°F (29°C) in water temperature is considered ideal, offering pleasure for extended periods without discomfort.
Daylight
The average length of the day in September is 12h and 20min.On the first day of September, sunrise is at 6:57 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 7:05 pm CDT.
Sunshine
The average sunshine in September is 8.9h.UV index
The months with the highest UV index are May through September, with an average maximum UV index of 7. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: In September, a daily UV index of 7 turns into the following recommendations:
Resist extreme sun exposure. Guarding against solar damage is essential. 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. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses. Notice! The reflection of water and sand increases the UV radiation significantly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in September?
What is the average humidity in September?
What is the rainiest month?
How much does it rain in September?
When it does not snow?
How warm is the water in September?
How many hours of daylight does Galveston have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
What is the month with the highest UV index?
How high is the UV index in September?
Average temperature in September
Galveston, TX
- Average high temperature in September: 84.2°F
The warmest month (with the highest average high temperature) is August (87.4°F).
The month with the lowest average high temperature is January (59.7°F).
- Average low temperature in September: 78.4°F
The month with the highest average low temperature is August (81.9°F).
The coldest month (with the lowest average low temperature) is January (51.6°F).
Average pressure in September
Galveston, 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
Galveston, TX
- Average wind speed in September: 9.6mph
The windiest month (with the highest average wind speed) is April (12.9mph).
The calmest month (with the lowest average wind speed) is August (9.4mph).
Average humidity in September
Galveston, TX
- Average humidity in September: 75%
The months with the highest relative humidity are February and March (81%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Galveston, TX
- Average rainfall in September: 4.29"
The wettest month (with the highest rainfall) is September (4.29").
The driest months (with the least rainfall) are February and March (0.75").
Average rainfall days in September
Galveston, TX
- Average rainfall days in September: 19.9 days
The month with the highest number of rainy days is September (19.9 days).
The month with the least rainy days is January (10.1 days).
Average snowfall days in September
Galveston, TX
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October, November and December (0 days).
Average sea temperature in September
Galveston, TX
- Average sea temperature in September: 83.8°F
The best month for swimming (with the highest average sea temperature) is August (87.2°F).
The coldest month (with the lowest average sea temperature) is January (56.5°F).
Average daylight in September /
Average sunshine in September
Galveston, TX
- Average daylight in September: 12h and 2min
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: 8h and 5min
The month with the most sunshine is August (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 4h and 54min).
Average sunshine days in September
Galveston, TX
- Average sunshine days in September: 8.5 days
The month with the most sunshine days is January (18.2 days).
The month with the least sunshine days is August (8.3 days).
Average UV index in September
Galveston, TX
- Average UV index in September: 7
The months with the highest UV index are May, June, July, August and September (UV index 7).
The months with the lowest UV index are January and December (UV index 4).
Average cloud cover in September
Galveston, TX
- Average cloud cover in September: 29
The month with the most cloud cover is February (Cloud cover 49).
The months with the least cloud cover are June, July, August and October (Cloud cover 26).
Average visibility in September
Galveston, 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).
Galveston, Texas, USA
Weather forecast for your location
2. Allow the app to use your location