September weather forecast
La Harpe, IL

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Weather in September

The first month of the autumn, September, is still a warm month in La Harpe, Illinois, with an average temperature ranging between min 57.4°F (14.1°C) and max 76.8°F (24.9°C).

Temperature

The shift from August to September includes a small decrease in the average high-temperature, from a moderately hot 82.2°F (27.9°C) to a still warm 76.8°F (24.9°C). An average low-temperature of 57.4°F (14.1°C) marks the nights in La Harpe, Illinois throughout September.

Humidity

The average relative humidity in September is 75%.

Rainfall

In La Harpe, in September, it is raining for 10.2 days, with typically 1.77" (45mm) of accumulated precipitation. Throughout the year, there are 127.6 rainfall days, and 21.02" (534mm) of precipitation is accumulated.

Snowfall

May through September are months without snowfall.

Daylight

In September, the average length of the day in La Harpe is 12h and 27min.
On the first day of September, sunrise is at 6:31 am and sunset at 7:35 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:47 pm CDT.

Sunshine

In September, the average sunshine is 9.3h.

UV index

In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.
Note: A daily high UV index of 5 in September leads to these guidelines:
Make use of precautions - It is urged to ward off sun damage. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
Updated: Jun 29, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature in La Harpe?

In September, the average high-temperature and low-temperature are 76.8°F (24.9°C) and 57.4°F (14.1°C) respectively. In August, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which represents the influence of relative humidity on air temperature, is appraised at 89.6°F (32°C).

What is the average humidity in September in La Harpe?

The average relative humidity in September is 75%.

How many days does it rain in September?

In La Harpe, in September, it is raining for 10.2 days, with typically 1.77" (45mm) of accumulated precipitation.

When it does not snow?

In La Harpe, snow does not fall in May through September.

Does it snow in September?

In La Harpe, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September?

In September, the average day length is 12h and 27min.

What time are sunrise and sunset in September?

On the first day of September in La Harpe, sunrise is at 6:31 am and sunset at 7:35 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:47 pm CDT.

How many hours of sunshine does La Harpe have in September?

In La Harpe, the average sunshine duration in September is 9.3h.

How high is the UV index in September?

In La Harpe, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate vulnerability from unsafe exposure to Sun's UV rays.
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
La Harpe, IL

Average temperature in September - La Harpe, IL
  • Average high temperature in September: 76.8°F

The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (30.9°F).

  • Average low temperature in September: 57.4°F

The month with the highest average low temperature is July (66.2°F).
The coldest month (with the lowest average low temperature) is January (18.7°F).

Average pressure in September
La Harpe, IL

Average pressure in September - La Harpe, IL
  • Average pressure in September: 30.02"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed in September
La Harpe, IL

Average wind speed in September - La Harpe, IL
  • Average wind speed in September: 7.6mph

The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (6.7mph).

Average humidity in September
La Harpe, IL

Average humidity in September - La Harpe, IL
  • Average humidity in September: 75%

The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).

Average rainfall in September
La Harpe, IL

Average rainfall in September - La Harpe, IL
  • Average rainfall in September: 1.77"

The wettest month (with the highest rainfall) is May (3.11").
The driest month (with the least rainfall) is January (0.83").

Average rainfall days in September
La Harpe, IL

Average rainfall days in September - La Harpe, IL
  • Average rainfall days in September: 10.2 days

The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (4.3 days).

Average snowfall in September
La Harpe, IL

Average snowfall in September - La Harpe, IL
  • Average snowfall in September: 0"

The month with the highest snowfall is January (3.15").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
La Harpe, IL

Average snowfall days in September - La Harpe, IL
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (8.5 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
La Harpe, IL

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

The month with the longest days is June (Average daylight: 15h and 0min).
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 0min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days in September
La Harpe, IL

Average sunshine days in September - La Harpe, IL
  • Average sunshine days in September: 18.4 days

The month with the most sunshine days is December (20 days).
The months with the least sunshine days are May and June (11.8 days).

Average UV index in September
La Harpe, IL

Average UV index in September - La Harpe, 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
La Harpe, IL

Average cloud cover in September - La Harpe, IL
  • Average cloud cover in September: 30

The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are August and September (Cloud cover 30).

Average visibility in September
La Harpe, IL

Average visibility in September - La Harpe, 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).

La Harpe, Illinois, USA

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