September weather forecastJoppa, IL
September
Weather in September
September, the first month of the autumn in Joppa, is also a moderately hot month, with an average temperature ranging between min 61.7°F (16.5°C) and max 81.5°F (27.5°C).Temperature
September's onset records an average high-temperature of a warm 81.5°F (27.5°C), a near match to August's 86.7°F (30.4°C). An average temperature of 61.7°F (16.5°C) is recorded in Joppa during the nights in September.Heat index
The heat index value during September is estimated at a hot 86°F (30°C). Continuing activity during long-lasting exposure might induce tiredness and result in heat cramps.Research indicates the heat index considers values in shaded locales and with light winds. A rise of up to 15 Fahrenheit (8 Celsius) degrees in the heat index could result from direct sunlight.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', gives an indication of how one might feel in terms of heat after considering humidity. The individual's impression of temperature can be affected by numerous factors such as metabolic variations, physical exertion, and attire. Direct sun rays have a notable impact on perceived temperature, which can raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Kids generally face higher risks than adults as they sweat less. Along with their large skin surface compared to their small bodies and higher heat production due to their activities, their vulnerability is increased.
Humidity
In September, the average relative humidity is 72%.Rainfall
September is the month with the least rainfall. Rain falls for 11.1 days and accumulates 1.5" (38mm) of precipitation.Snowfall
In Joppa, snow does not fall in May through October.Daylight
In September, the average length of the day is 12h and 25min.On the first day of September in Joppa, sunrise is at 6:26 am and sunset at 7:23 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:39 pm CDT.
Sunshine
In September, the average sunshine is 9.6h.UV index
In Joppa, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: In September, the maximum UV index of 5 suggests this advice:
Undertake protective steps - Preventing sun damage is advised. Considering the Sun's intensity during midday, it's wise to minimize direct exposure. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Joppa, IL
- Average high temperature in September: 81.5°F
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is January (41.4°F).
- Average low temperature in September: 61.7°F
The month with the highest average low temperature is July (68.9°F).
The coldest month (with the lowest average low temperature) is January (28°F).
Average pressure in September
Joppa, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Joppa, IL
- Average wind speed in September: 6.3mph
The windiest months (with the highest average wind speed) are January, March and April (8.9mph).
The calmest months (with the lowest average wind speed) are July and August (5.6mph).
Average humidity in September
Joppa, IL
- Average humidity in September: 72%
The months with the highest relative humidity are March and May (79%).
The month with the lowest relative humidity is October (70%).
Average rainfall in September
Joppa, IL
- Average rainfall in September: 1.5"
The wettest month (with the highest rainfall) is April (4.29").
The driest month (with the least rainfall) is September (1.5").
Average rainfall days in September
Joppa, IL
- Average rainfall days in September: 11.1 days
The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is October (10.2 days).
Average snowfall in September
Joppa, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.61").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Joppa, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (4.3 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
Joppa, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 9h and 36min
The months with the most sunshine are June and July (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).
Average sunshine days in September
Joppa, IL
- Average sunshine days in September: 16.9 days
The month with the most sunshine days is October (19.3 days).
The month with the least sunshine days is May (11 days).
Average UV index in September
Joppa, IL
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover in September
Joppa, IL
- Average cloud cover in September: 26
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is September (Cloud cover 26).
Average visibility in September
Joppa, 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).





