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
In Altair, the average high-temperature in September gently drops from a tropical 94.6°F (34.8°C) in August to a still hot 88.2°F (31.2°C). September nights are marked by an average temperature drop to a pleasant 71.8°F (22.1°C).Heat index
For September, the heat index is estimated at a blisteringly hot 104°F (40°C). Take extra safety measures to prevent heat exhaustion and heat cramps. Heatstroke could follow lengthy activity.Take into consideration that the heat index values are calculated for shade and light wind conditions. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', measures the perceived warmth when incorporating the humidity present in the air. One's perception of temperature can vary depending on physical activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. When in direct sunlight, one should be cautious as it can raise the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. Typically, children face more danger than adults as they usually perspire less. Their larger skin surface relative to their small bodies and increased heat output from their activities enhance their risk.
In the face of high temperatures, the human body's reflex is to perspire, leveraging sweat evaporation for cooling. Increased relative humidity slows down evaporation, thereby decreasing the rate of heat removal from the body, culminating in a sensation of overheating. Heat absorption that surpasses the body's shedding capability can lead to overheating and varying levels of dehydration.
Humidity
In Altair, the average relative humidity in September is 75%.Rainfall
In Altair, during September, the rain falls for 19 days and regularly aggregates up to 3.66" (93mm) of precipitation. Throughout the year, there are 166.4 rainfall days, and 30.71" (780mm) of precipitation is accumulated.Snowfall
In Altair, Texas, snow does not fall in March through November.Daylight
The average length of the day in September is 12h and 20min.On the first day of September, sunrise is at 7:03 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 7:12 pm CDT.
Sunshine
The average sunshine in September is 8.3h.UV index
The average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: A daily maximum UV index of 6 in September translates into the following instructions:
Refrain from overexposure. Fair-skinned individuals could burn in under 20 minutes. From 10 a.m. to 4 p.m., when UV radiation is at its strongest, limit direct exposure to the Sun and note that shade structures may not provide full sun protection. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
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 many days does it rain in September?
When it does not snow?
How many hours of daylight does Altair have 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
Altair, TX
- Average high temperature in September: 88.2°F
The warmest month (with the highest average high temperature) is August (94.6°F).
The month with the lowest average high temperature is January (61°F).
- Average low temperature in September: 71.8°F
The month with the highest average low temperature is August (75.4°F).
The coldest month (with the lowest average low temperature) is January (45°F).
Average pressure in September
Altair, 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
Altair, TX
- Average wind speed in September: 5.8mph
The windiest month (with the highest average wind speed) is April (8.7mph).
The calmest month (with the lowest average wind speed) is September (5.8mph).
Average humidity in September
Altair, TX
- Average humidity in September: 75%
The months with the highest relative humidity are February, March, May and June (78%).
The month with the lowest relative humidity is August (71%).
Average rainfall in September
Altair, TX
- Average rainfall in September: 3.66"
The wettest month (with the highest rainfall) is May (4.13").
The driest months (with the least rainfall) are January and February (1.46").
Average rainfall days in September
Altair, TX
- Average rainfall days in September: 19 days
The month with the highest number of rainy days is September (19 days).
The month with the least rainy days is January (10.3 days).
Average snowfall in September
Altair, TX
- Average snowfall in September: 0"
The months with the highest snowfall are January and December (0.08").
The months with the least snowfall are March, April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Altair, 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 and November (0 days).
Average daylight in September /
Average sunshine in September
Altair, 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 2min
The month with the most sunshine is August (Average sunshine: 9h and 48min).
The month with the least sunshine is December (Average sunshine: 4h and 48min).
Average sunshine days in September
Altair, TX
- Average sunshine days in September: 8.8 days
The month with the most sunshine days is January (19.4 days).
The month with the least sunshine days is September (8.8 days).
Average UV index in September
Altair, 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
Altair, TX
- Average cloud cover in September: 35
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Altair, TX
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, August, September, October, November and December (6mi).
The months with the lowest visibility are May, June and July (5mi).
Altair, Texas, USA
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