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
Entering September, Altona's average high-temperature reads a still warm 75.4°F (24.1°C), indicating a close resemblance to the previous month's climate. The temperature in Altona lowers to an average of 56.3°F (13.5°C) during September nights.Humidity
In September, the average relative humidity in Altona is 76%.Rainfall
In Altona, during September, the rain falls for 9.9 days and regularly aggregates up to 1.26" (32mm) of precipitation. Throughout the year, there are 127.7 rainfall days, and 17.8" (452mm) of precipitation is accumulated.Snowfall
In Altona, snow does not fall in May through September.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:28 am and sunset at 7:32 pm. On the last day of September, in Altona, sunrise is at 6:57 am and sunset at 6:43 pm CDT.
Sunshine
The average sunshine in September is 9.4h.UV index
In September, the average daily maximum UV index in Altona is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.Note: A typical high UV index of 4 in September suggests the following recommendations:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Altona in September?
What is the average humidity in September in Altona?
How many days does it rain in September in Altona?
When it does not snow in Altona?
Does it snow in Altona in September?
What is the average length of the day in September in Altona?
What time are sunrise and sunset in September in Altona?
How many hours of sunshine does Altona have in September?
What is the UV index reading in September in Altona?
Average temperature in September
Altona, IL
- Average high temperature in September: 75.4°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (28.2°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (16.5°F).
Average pressure in September
Altona, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in September
Altona, IL
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in September
Altona, IL
- Average humidity in September: 76%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Altona, IL
- Average rainfall in September: 1.26"
The wettest month (with the highest rainfall) is May (2.76").
The driest month (with the least rainfall) is December (0.71").
Average rainfall days in September
Altona, IL
- Average rainfall days in September: 9.9 days
The month with the highest number of rainy days is May (16.5 days).
The month with the least rainy days is January (4 days).
Average snowfall in September
Altona, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.17").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Altona, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.5 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
Altona, IL
- 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: 9h and 2min
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
Altona, IL
- Average sunshine days in September: 18 days
The month with the most sunshine days is November (19.7 days).
The month with the least sunshine days is July (11.2 days).
Average UV index in September
Altona, IL
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Altona, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is September (Cloud cover 29).
Average visibility in September
Altona, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
Altona, Illinois, USA
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