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
Plymouth marks the onset of September with an average high-temperature of a still moderately hot 76.8°F (24.9°C), a subtle shift from August's 82°F (27.8°C). In Plymouth, in September, the average low-temperature is a moderate 57.6°F (14.2°C).Humidity
In September, the average relative humidity is 75%.Rainfall
In Plymouth, in September, it is raining for 7.7 days, with typically 0.87" (22mm) of accumulated precipitation. Throughout the year, there are 94.4 rainfall days, and 7.76" (197mm) of precipitation is accumulated.Snowfall
In Plymouth, snow does not fall in May through September.Daylight
In September, the average length of the day is 12h and 26min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:34 pm. On the last day of September, sunrise is at 6:59 am and sunset at 6:47 pm CDT.
Sunshine
In Plymouth, the average sunshine in September is 9.4h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.Note: The daily high UV index of 4 in September translates into this advice:
Put precautions into practice - Ensuring skin and eye safety is a necessity. To avoid the Sun's strongest rays, limit exposure around the mid-day period. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Plymouth have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Plymouth have in September?
How high is the UV index in September in Plymouth?
Average temperature in September
Plymouth, IL
- Average high temperature in September: 76.8°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (31.1°F).
- Average low temperature in September: 57.6°F
The month with the highest average low temperature is July (66.2°F).
The coldest month (with the lowest average low temperature) is January (19°F).
Average pressure in September
Plymouth, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Plymouth, IL
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is January (10.5mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).
Average humidity in September
Plymouth, IL
- Average humidity in September: 75%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Plymouth, IL
- Average rainfall in September: 0.87"
The wettest month (with the highest rainfall) is May (1.1").
The driest month (with the least rainfall) is December (0.35").
Average rainfall days in September
Plymouth, IL
- Average rainfall days in September: 7.7 days
The month with the highest number of rainy days is May (12.3 days).
The month with the least rainy days is January (3.3 days).
Average snowfall in September
Plymouth, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.67").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Plymouth, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.3 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
Plymouth, IL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 9h and 2min
The months with the most sunshine are June and July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Plymouth, IL
- Average sunshine days in September: 20.4 days
The month with the most sunshine days is December (23.5 days).
The month with the least sunshine days is June (13.9 days).
Average UV index in September
Plymouth, IL
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Plymouth, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Plymouth, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Plymouth, Illinois, USA
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