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 unfolding of September shows an average high-temperature of a still moderately hot 73.8°F (23.2°C), indicating a slight variance from August's 78.8°F (26°C). During September, Knox records an average temperature of 56.3°F (13.5°C) at night.Humidity
In September, the average relative humidity is 79%.Rainfall
In Knox, in September, during 14.9 rainfall days, 2.17" (55mm) of precipitation is typically accumulated. In Knox, during the entire year, the rain falls for 175.4 days and collects up to 34.29" (871mm) of precipitation.Snowfall
In Knox, Indiana, snow does not fall in June through September.Daylight
In Knox, Indiana, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:13 am and sunset at 7:18 pm. On the last day of September, sunrise is at 6:42 am and sunset at 6:29 pm CDT.
Sunshine
The average sunshine in September is 8.3h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Make use of precautions - Shielding skin and eyes from injury is a requirement. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Knox?
What is the average humidity in September in Knox?
How many days does it rain in September in Knox?
When it does not snow in Knox?
Does it snow in Knox in September?
How many hours of daylight does Knox have in September?
When is the sunrise / sunset in September in Knox?
How long on average sun shines in September in Knox?
How high is the UV index in September in Knox?
Average temperature in September
Knox, IN
- Average high temperature in September: 73.8°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (29.8°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in September
Knox, IN
- Average pressure in September: 30.03"Hg
The months with the highest atmospheric pressure are January and November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Knox, IN
- Average wind speed in September: 7mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).
Average humidity in September
Knox, IN
- Average humidity in September: 79%
The months with the highest relative humidity are January, February and July (84%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Knox, IN
- Average rainfall in September: 2.17"
The wettest month (with the highest rainfall) is May (4.45").
The driest month (with the least rainfall) is January (1.85").
Average rainfall days in September
Knox, IN
- Average rainfall days in September: 14.9 days
The month with the highest number of rainy days is May (20.7 days).
The month with the least rainy days is January (7.9 days).
Average snowfall in September
Knox, IN
- Average snowfall in September: 0"
The month with the highest snowfall is February (5.04").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Knox, IN
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (15.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Knox, IN
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 2min
The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).
Average sunshine days in September
Knox, IN
- Average sunshine days in September: 13 days
The month with the most sunshine days is November (14.6 days).
The month with the least sunshine days is June (7.8 days).
Average UV index in September
Knox, IN
- Average UV index in September: 4
The month with the highest UV index is June (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Knox, IN
- Average cloud cover in September: 35
The month with the most cloud cover is January (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in September
Knox, IN
- Average visibility in September: 5mi
The months with the highest visibility are March, April, May, June, October, November and December (6mi).
The months with the lowest visibility are January, February, July, August and September (5mi).
Knox, Indiana, USA
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