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
September's arrival signals a moderate reduction in the average high-temperature, easing from 94.6°F (34.8°C) in August to a still hot 88.7°F (31.5°C). In the month of September, Katy records a consistent average low-temperature of 71.8°F (22.1°C).Heat index
September's heat index is evaluated at a blistering 105.8°F (41°C). Apply extra caution, heat cramps and heat exhaustion could happen. Heatstroke might occur with long-duration activity.Be advised, the heat index considers values for conditions in shade and with a light breeze. An exposure to direct sunlight may lift the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', melds the effects of warmth and moisture to generate a feeling of heat. 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 exposed to direct sunlight, it's possible for the heat index to increase by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Young ones are generally more prone to risk than adults due to their reduced ability to sweat. Their large skin surface area relative to their diminutive bodies and elevated heat production from their activities further enhance this risk.
Evaporating sweat is a key way the human body dispels excessive warmth, all thanks to the process of perspiration. Increased relative humidity slows down evaporation, thereby decreasing the rate of heat removal from the body, culminating in a sensation of overheating. Heat-related complications, like dehydration, can manifest if the body's heat gain exceeds its dissipation capacity.
Humidity
In Katy, the average relative humidity in September is 75%.Rainfall
In Katy, in September, it is raining for 18.8 days, with typically 3.66" (93mm) of accumulated precipitation. Throughout the year, there are 169 rainfall days, and 30.12" (765mm) of precipitation is accumulated.Snowfall
In Katy, snow does not fall in February through November.Daylight
In Katy, the average length of the day in September is 12h and 20min.On the first day of September, sunrise is at 7:00 am and sunset at 7:45 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 7:09 pm CDT.
Sunshine
In Katy, the average sunshine in September is 8.5h.UV index
The average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health hazard from unprotected exposure to Sun's UV rays for the average person.Note: The maximum UV index of 6 during September translates into these guidelines:
Guard oneself from overexposure. Defence against sun injury is vital. 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. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Katy have in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Katy, TX
- Average high temperature in September: 88.7°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 (75.7°F).
The coldest month (with the lowest average low temperature) is January (45°F).
Average pressure in September
Katy, 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
Katy, TX
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is April (8.4mph).
The calmest month (with the lowest average wind speed) is September (5.7mph).
Average humidity in September
Katy, TX
- Average humidity in September: 75%
The months with the highest relative humidity are February and March (78%).
The months with the lowest relative humidity are August and October (71%).
Average rainfall in September
Katy, TX
- Average rainfall in September: 3.66"
The wettest month (with the highest rainfall) is May (4.29").
The driest month (with the least rainfall) is February (1.42").
Average rainfall days in September
Katy, TX
- Average rainfall days in September: 18.8 days
The month with the highest number of rainy days is September (18.8 days).
The month with the least rainy days is January (10.5 days).
Average snowfall in September
Katy, TX
- Average snowfall in September: 0"
The month with the highest snowfall is December (0.12").
The months with the least snowfall are February, March, April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Katy, TX
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.4 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
Katy, 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 3min
The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is December (Average sunshine: 4h and 54min).
Average sunshine days in September
Katy, TX
- Average sunshine days in September: 8.9 days
The month with the most sunshine days is January (18.7 days).
The month with the least sunshine days is September (8.9 days).
Average UV index in September
Katy, 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
Katy, TX
- Average cloud cover in September: 33
The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Katy, TX
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, June, August, September, October, November and December (6mi).
The months with the lowest visibility are April, May and July (5mi).
Katy, Texas, USA
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