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 onset of September is marked by a minor decrease in temperature, transitioning from a warm 84.6°F (29.2°C) in August to a still moderately hot 78.3°F (25.7°C). Williamstown observes an average nighttime temperature of 58.5°F (14.7°C) during September.Humidity
In Williamstown, the average relative humidity in September is 75%.Rainfall
The month with the least rainfall in Williamstown is September, when the rain falls for 13.9 days and typically collects 2.13" (54mm) of precipitation.Snowfall
May through September are months without snowfall in Williamstown, Kentucky.Daylight
The average length of the day in September in Williamstown is 12h and 25min.On the first day of September in Williamstown, sunrise is at 7:08 am and sunset at 8:07 pm. On the last day of the month, sunrise is at 7:33 am and sunset at 7:22 pm EDT.
Sunshine
In Williamstown, the average sunshine in September is 8.2h.UV index
In Williamstown, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: A maximum UV index of 5 in September translates into the following recommendations:
Undertake protective steps - Recommendations to avoid sunburn are issued. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Frequently asked questions
What are September temperatures in Williamstown?
What is the average humidity in September in Williamstown?
What is the driest month in Williamstown?
How many days does it rain in September in Williamstown?
When it does not snow in Williamstown?
Does it snow in Williamstown in September?
How many hours of daylight does Williamstown have in September?
When is the sunrise / sunset in September in Williamstown?
How many hours of sunshine does Williamstown have in September?
How high is the UV index in September in Williamstown?
Average temperature in September
Williamstown, KY
- Average high temperature in September: 78.3°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is January (37°F).
- Average low temperature in September: 58.5°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (24.6°F).
Average pressure in September
Williamstown, KY
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January and November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Williamstown, KY
- Average wind speed in September: 5.5mph
The windiest month (with the highest average wind speed) is January (8.6mph).
The calmest months (with the lowest average wind speed) are July and August (5mph).
Average humidity in September
Williamstown, KY
- Average humidity in September: 75%
The months with the highest relative humidity are February and December (81%).
The month with the lowest relative humidity is August (74%).
Average rainfall in September
Williamstown, KY
- Average rainfall in September: 2.13"
The wettest month (with the highest rainfall) is April (3.82").
The driest month (with the least rainfall) is September (2.13").
Average rainfall days in September
Williamstown, KY
- Average rainfall days in September: 13.9 days
The month with the highest number of rainy days is May (18.8 days).
The month with the least rainy days is November (10.6 days).
Average snowfall in September
Williamstown, KY
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.35").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Williamstown, KY
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Williamstown, KY
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 8h and 1min
The months with the most sunshine are June and July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in September
Williamstown, KY
- Average sunshine days in September: 14.4 days
The month with the most sunshine days is October (17 days).
The month with the least sunshine days is February (10.5 days).
Average UV index in September
Williamstown, KY
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Williamstown, KY
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Williamstown, KY
- Average visibility in September: 6mi
The months with the highest visibility are March, April, June, August, September, October and November (6mi).
The months with the lowest visibility are January, February, May, July and December (5mi).
Williamstown, Kentucky, USA
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