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
September commences with an average high-temperature of a still warm 77.5°F (25.3°C), showing little deviation from August's 82.2°F (27.9°C). An average nighttime temperature of 59.4°F (15.2°C) is noted during the month of September.Humidity
In September, the average relative humidity is 75%.Rainfall
In Altamont, in September, it is raining for 10.8 days, with typically 1.54" (39mm) of accumulated precipitation. In Altamont, during the entire year, the rain falls for 141.3 days and collects up to 26.77" (680mm) of precipitation.Snowfall
In Altamont, snow does not fall in April through October.Daylight
The average length of the day in September in Altamont is 12h and 26min.On the first day of September in Altamont, sunrise is at 6:24 am and sunset at 7:25 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:38 pm CDT.
Sunshine
In September, the average sunshine in Altamont is 9.2h.UV index
In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the ordinary person.Note: The UV index of 5 during September leads to these advisories:
Take precautions - Protection against skin and eye damage is obliged. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat.
Frequently asked questions
What is the average September temperature in Altamont?
What is the average humidity in September in Altamont?
How much does it rain in Altamont in September?
When it does not snow in Altamont?
What is the average length of the day in September in Altamont?
What time are sunrise and sunset in September in Altamont?
How many hours of sunshine does Altamont have in September?
What is the UV index reading in September in Altamont?
Average temperature in September
Altamont, IL
- Average high temperature in September: 77.5°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (35.6°F).
- Average low temperature in September: 59.4°F
The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure in September
Altamont, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Altamont, IL
- Average wind speed in September: 6.7mph
The windiest months (with the highest average wind speed) are January and February (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity in September
Altamont, IL
- Average humidity in September: 75%
The months with the highest relative humidity are July and August (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Altamont, IL
- Average rainfall in September: 1.54"
The wettest month (with the highest rainfall) is April (3.35").
The driest month (with the least rainfall) is February (1.38").
Average rainfall days in September
Altamont, IL
- Average rainfall days in September: 10.8 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (7.3 days).
Average snowfall in September
Altamont, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.01").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Altamont, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (5.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Altamont, IL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in September
Altamont, IL
- Average sunshine days in September: 17.1 days
The month with the most sunshine days is December (19.5 days).
The month with the least sunshine days is May (10.8 days).
Average UV index in September
Altamont, IL
- 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
Altamont, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 53).
The months with the least cloud cover are June and September (Cloud cover 29).
Average visibility in September
Altamont, 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).
Altamont, Illinois, USA
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