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
In Lanark, the average high-temperature in September slightly decreases from a moderately hot 78.4°F (25.8°C) in August to an agreeable 72.9°F (22.7°C). During September nights, Lanark witnesses a consistent average temperature of 54.5°F (12.5°C).Humidity
The average relative humidity in September is 79%.Rainfall
In Lanark, during September, the rain falls for 10.7 days and regularly aggregates up to 1.5" (38mm) of precipitation. In Lanark, during the entire year, the rain falls for 130.8 days and collects up to 17.95" (456mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
In Lanark, the average length of the day in September is 12h and 28min.On the first day of September in Lanark, Illinois, sunrise is at 6:25 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 6:42 pm CDT.
Sunshine
The average sunshine in September in Lanark is 9h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the average person.Note: The UV index of 4 during September translates into the following guidance:
Act with care - The suggestion to avoid sunburn is emphasized. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck.
Frequently asked questions
What are the temperatures in Lanark in September?
What is the average humidity in September in Lanark?
How much does it rain in Lanark in September?
When it does not snow in Lanark?
Does it snow in Lanark in September?
What is the average length of the day in September in Lanark?
When is the sunrise / sunset in September in Lanark?
How long on average sun shines in September in Lanark?
What is the UV index reading in September in Lanark?
Average temperature in September
Lanark, IL
- Average high temperature in September: 72.9°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (25.9°F).
- Average low temperature in September: 54.5°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 (13.5°F).
Average pressure in September
Lanark, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Lanark, IL
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Lanark, IL
- Average humidity in September: 79%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (75%).
Average rainfall in September
Lanark, IL
- Average rainfall in September: 1.5"
The wettest month (with the highest rainfall) is May (2.76").
The driest months (with the least rainfall) are January and February (0.71").
Average rainfall days in September
Lanark, IL
- Average rainfall days in September: 10.7 days
The month with the highest number of rainy days is May (17.9 days).
The month with the least rainy days is February (4.4 days).
Average snowfall in September
Lanark, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.64").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Lanark, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.2 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
Lanark, IL
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Lanark, IL
- Average sunshine days in September: 17.8 days
The month with the most sunshine days is November (19.7 days).
The month with the least sunshine days is June (10 days).
Average UV index in September
Lanark, IL
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Lanark, IL
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is September (Cloud cover 32).
Average visibility in September
Lanark, IL
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
Lanark, Illinois, USA
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