September weather forecast
Lafayette, IN

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Weather in September

September marks the onset of fall and brings a significant change to Lafayette's weather pattern. Temperatures start to decrease, with the highs dropping to about 75.6°F (24.2°C). The shift in weather is apparent with noticeably shorter days and a drop in humidity levels. As we trade summer for fall, September binds both warm afternoons and cool evenings - an amalgamation residents look forward to. With a change in season, Lafayette's landscape begins its transformation into shades of fall.

Temperature

The advent of September brings an average high-temperature of a still warm 75.6°F (24.2°C), almost identical to the preceding month. September witnesses an average nighttime temperature of 57°F (13.9°C).

Humidity

The average relative humidity in September in Lafayette, Indiana, is 78%.

Rainfall

September is the month with the least rainfall. Rain falls for 11.2 days and accumulates 1.1" (28mm) of precipitation.

Snowfall

In Lafayette, snow does not fall in May through October.

Daylight

In Lafayette, the average length of the day in September is 12h and 27min.
On the first day of the month, sunrise is at 7:15 am and sunset at 8:18 pm. On the last day of September, sunrise is at 7:43 am and sunset at 7:30 pm EDT.

Sunshine

In Lafayette, the average sunshine in September is 8.2h.

UV index

In September, the average daily maximum UV index in Lafayette is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for average individuals.
Note: A maximum daily UV index of 5 during September morphs into the following directions:
Take necessary precautions - Suggestions to elude sunburn are provided. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Updated: Aug 25, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature?

The high-temperature, in September, in Lafayette, records 75.6°F (24.2°C), while the low-temperature is 57°F (13.9°C). In July, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, is evaluated at 87.8°F (31°C).

What is the average humidity in September?

In September, the average relative humidity is 78%.

What is the driest month?

The month with the least rainfall is September, when the rain falls for 11.2 days and typically collects 1.1" (28mm) of precipitation.

How much does it rain in Lafayette in September?

In Lafayette, in September, it is raining for 11.2 days, with typically 1.1" (28mm) of accumulated precipitation.

When it does not snow?

In Lafayette, Indiana, snow does not fall in May through October.

What is the average length of the day in September?

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

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 7:15 am and sunset at 8:18 pm. On the last day of the month, sunrise is at 7:43 am and sunset at 7:30 pm EDT.

How many hours of sunshine does Lafayette have in September?

In September, the average sunshine duration is 8.2h.

How high is the UV index in September?

The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium health risk 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
Lafayette, IN

Average temperature in September - Lafayette, IN
  • Average high temperature in September: 75.6°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 (31.8°F).

  • Average low temperature in September: 57°F

The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).

Average pressure in September
Lafayette, IN

Average pressure in September - Lafayette, IN
  • Average pressure in September: 30.03"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in September
Lafayette, IN

Average wind speed in September - Lafayette, IN
  • Average wind speed in September: 7.1mph

The windiest month (with the highest average wind speed) is January (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6.2mph).

Average humidity in September
Lafayette, IN

Average humidity in September - Lafayette, IN
  • Average humidity in September: 78%

The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (73%).

Average rainfall in September
Lafayette, IN

Average rainfall in September - Lafayette, IN
  • Average rainfall in September: 1.1"

The wettest months (with the highest rainfall) are April and May (2.8").
The driest month (with the least rainfall) is September (1.1").

Average rainfall days in September
Lafayette, IN

Average rainfall days in September - Lafayette, IN
  • Average rainfall days in September: 11.2 days

The month with the highest number of rainy days is May (18.5 days).
The month with the least rainy days is February (6.5 days).

Average snowfall in September
Lafayette, IN

Average snowfall in September - Lafayette, IN
  • Average snowfall in September: 0"

The months with the highest snowfall are January and February (2.44").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Lafayette, IN

Average snowfall days in September - Lafayette, IN
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (11.1 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Lafayette, IN

Average daylight in September / Average sunshine in September - Lafayette, IN
  • 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: 8h and 1min

The months with the most sunshine are June and July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).

Average sunshine days in September
Lafayette, IN

Average sunshine days in September - Lafayette, IN
  • Average sunshine days in September: 14.9 days

The month with the most sunshine days is November (18.3 days).
The month with the least sunshine days is May (9.8 days).

Average UV index in September
Lafayette, IN

Average UV index in September - Lafayette, IN
  • Average UV index in September: 5

The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in September
Lafayette, IN

Average cloud cover in September - Lafayette, IN
  • Average cloud cover in September: 34

The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are June and August (Cloud cover 33).

Average visibility in September
Lafayette, IN

Average visibility in September - Lafayette, IN
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).

Lafayette, Indiana, USA

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