September weather forecast
Joppa, IL

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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.
Updated: Jun 11, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September?

The high-temperature during September is 81.5°F (27.5°C) and the low-temperature is 61.7°F (16.5°C). In September, the average heat index (a.k.a. 'feels like', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, is estimated at 86°F (30°C).

What is the average humidity in September?

In Joppa, Illinois, the average relative humidity in September is 72%.

What is the driest month?

The month with the least rainfall is September, when the rain falls for 11.1 days and typically collects 1.5" (38mm) of precipitation.

How much does it rain in September?

In September, the rain falls for 11.1 days. Throughout September, 1.5" (38mm) of precipitation is accumulated.

When it does not snow?

May through October are months without snowfall.

What is the average length of the day in September?

The average day length in September is 12h and 25min.

What time are sunrise and sunset in September in Joppa?

On the first day of September, 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.

How many hours of sunshine does Joppa have in September?

In September, the average sunshine duration in Joppa is 9.6h.

How high is the UV index in September?

In Joppa, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium health risk from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Joppa, IL

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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 / Average sunshine in September - Joppa, IL
  • Average daylight in September: 12h and 2min

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 4min

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 - 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 - 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 - 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 - 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).

Joppa, Illinois, USA

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