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
The advent of September brings an average high-temperature of a still hot 87.4°F (30.8°C), almost identical to the preceding month. During the September nights, an average temperature of 67.8°F (19.9°C) is observed.Heat index
The heat index for September is appraised at a fiery hot 102.2°F (39°C). Ensure additional precautions, heat exhaustion and heat cramps may be expected. Heatstroke could occur from sustained activity.It is emphasized that the heat index's values are meant for shaded zones with mild winds. Direct exposure to sunshine could lead to a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', comes about by integrating the temperature readings with the humidity levels. Metabolic differences, pregnancy status, and the level of physical activity are additional factors influencing an individual's weather perception. One must note that being under the direct sun can escalate the heat's effects, with the heat index possibly rising by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Kids frequently fail to realize the necessity for resting and hydrating. Thirst is an advanced indication of dehydration - hence, maintaining hydration, especially during extended physical activities, becomes essential.
The natural cooling mechanism in humans involves perspiration, where the evaporation of sweat balances out excessive warmth. With high air temperature and humidity (high heat index) conditions, sweat production is restricted, leading to an amplified perception of heat. Overheating can ensue when the body accumulates more heat than it can release, and dehydration severity may vary.
Humidity
The average relative humidity in September is 75%.Rainfall
In Williamsburg, in September, during 15 rainfall days, 2.56" (65mm) of precipitation is typically accumulated. Throughout the year, there are 168 rainfall days, and 34.17" (868mm) of precipitation is accumulated.Snowfall
In Williamsburg, snow does not fall in April through November.Daylight
In September, the average length of the day is 12h and 21min.On the first day of the month, sunrise is at 6:34 am and sunset at 7:21 pm. On the last day of September, sunrise is at 6:52 am and sunset at 6:44 pm CDT.
Sunshine
The average sunshine in September is 9.3h.UV index
The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.Note: A maximum high daily UV index of 5 during September translates into the following directions:
Exercise prevention - Precautions against solar damage are endorsed. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking 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 many days does it rain in September?
When it does not snow?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Williamsburg have in September?
How high is the UV index in September?
Average temperature in September
Williamsburg, MS
- Average high temperature in September: 87.4°F
The warmest month (with the highest average high temperature) is August (91.4°F).
The month with the lowest average high temperature is January (55.9°F).
- Average low temperature in September: 67.8°F
The month with the highest average low temperature is July (72.1°F).
The coldest month (with the lowest average low temperature) is January (39°F).
Average pressure in September
Williamsburg, MS
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The months with the lowest atmospheric pressure are June and August (29.97"Hg).
Average wind speed in September
Williamsburg, MS
- Average wind speed in September: 5mph
The windiest months (with the highest average wind speed) are January, February and April (7.3mph).
The calmest months (with the lowest average wind speed) are July and August (4.7mph).
Average humidity in September
Williamsburg, MS
- Average humidity in September: 75%
The month with the highest relative humidity is December (82%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Williamsburg, MS
- Average rainfall in September: 2.56"
The wettest month (with the highest rainfall) is December (3.74").
The driest month (with the least rainfall) is November (2.01").
Average rainfall days in September
Williamsburg, MS
- Average rainfall days in September: 15 days
The month with the highest number of rainy days is August (20.3 days).
The month with the least rainy days is November (8.7 days).
Average snowfall in September
Williamsburg, MS
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.24").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Williamsburg, MS
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (0.3 days).
The months with the least snowfall days are April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
Williamsburg, MS
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 12min).
The month with the shortest days is December (Average daylight: 10h and 6min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The months with the least sunshine are February and December (Average sunshine: 4h and 54min).
Average sunshine days in September
Williamsburg, MS
- Average sunshine days in September: 13.4 days
The month with the most sunshine days is October (19.9 days).
The month with the least sunshine days is August (9 days).
Average UV index in September
Williamsburg, MS
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January and December (UV index 3).
Average cloud cover in September
Williamsburg, MS
- Average cloud cover in September: 31
The months with the most cloud cover are February and December (Cloud cover 49).
The month with the least cloud cover is October (Cloud cover 29).
Average visibility in September
Williamsburg, MS
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, June, October, November and December (6mi).
The months with the lowest visibility are May, July, August and September (5mi).
Williamsburg, Mississippi, USA
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