September weather forecast and climate
Riley, KS

September, the first month of the autumn, in Riley, is still a warm month, with temperature in the range of an average low of 60.4°F (15.8°C) and an average high of 79.7°F (26.5°C).

Temperature

In September, the average high-temperature slightly decreases, from a tropical 87.4°F (30.8°C) in August, to a moderately hot 79.7°F (26.5°C). In Riley, the average low-temperature is 60.4°F (15.8°C).

Humidity

In September, the average relative humidity in Riley, Kansas, is 68%.

Rainfall

In September, in Riley, the rain falls for 11.5 days. Throughout September, 1.65" (42mm) of precipitation is accumulated. Throughout the year, in Riley, there are 114.8 rainfall days, and 21.1" (536mm) of precipitation is accumulated.

Snowfall

In Riley, Kansas, snow does not fall in May through September.

Daylight

In Riley, the average length of the day in September is 12.4h.

Sunshine

In Riley, the average sunshine in September is 8.9h.

UV index

The average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to the UV radiation for the ordinary person.
Note: The daily maximum UV index of 5 interpret into the following advice:
Take precautions - Protection against sunburn is recommended. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.

What is the temperature in September in Riley?

The average high-temperature, in September, in Riley, Kansas, is 79.7°F (26.5°C), while the average low-temperature is 60.4°F (15.8°C).

What is the average humidity in September in Riley?

In Riley, the average relative humidity in September is 68%.

How many days does it rain in September in Riley?

In Riley, in September, it is raining for 11.5 days, with typically 1.65" (42mm) of accumulated precipitation.

Does it snow in Riley in September?

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

When it does not snow in Riley?

In Riley, Kansas, snow does not fall in May through September.

What is the average length of the day in September in Riley?

In September, the average length of the day in Riley is 12.4h.

How many hours of sunshine does Riley have in September?

In September, the average sunshine is 8.9h.

What is the UV index intensity in September in Riley?

The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate vulnerability from the exposure to the Sun's UV rays.
Average temperature in September - Riley, KS
  • Average high temperature in September: 79.7°F

The warmest month (with the highest average high temperature) is July (89.6°F).
The month with the lowest average high temperature is January (38.8°F).

  • Average low temperature in September: 60.4°F

The month with the highest average low temperature is July (69.8°F).
The coldest month (with the lowest average low temperature) is January (23°F).

Average pressure in September - Riley, KS
  • Average pressure in September: 29.98"

The month with the highest atmospheric pressure is January (30.16").
The month with the lowest atmospheric pressure is June (29.85").

Average wind speed in September - Riley, KS
  • Average wind speed in September: 9.6mph

The windiest month (with the highest average wind speed) is April (11.8mph).
The calmest month (with the lowest average wind speed) is August (8.6mph).

Average humidity in September - Riley, KS
  • Average humidity in September: 68%

The month with the highest relative humidity is May (74%).
The month with the lowest relative humidity is October (64%).

Average rainfall in September - Riley, KS
  • Average rainfall in September: 1.65"

The wettest month (with the highest rainfall) is May (3.98").
The driest month (with the least rainfall) is January (0.63").

Average rainfall days in September - Riley, KS
  • Average rainfall days in September: 11.5 days

The month with the highest number of rainy days is May (14.3 days).
The month with the least rainy days is January (3.7 days).

Average snowfall in September - Riley, KS
  • Average snowfall in September: 0"

The month with the highest snowfall is February (2.24").
Months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September - Riley, KS
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (4.8 days).
Months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in September / Average sunshine in September - Riley, KS
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.9h).
The month with the shortest days is December (Average daylight: 9.4h).

  • Average sunshine in September: 8.9h

Months with the most sunshine are June and July (Average sunshine: 10.9h).
The month with the least sunshine is December (Average sunshine: 5.7h).

Average sunshine days in September - Riley, KS
  • Average sunshine days in September: 16.5 days

The month with the most sunshine days is January (23.5 days).
The month with the least sunshine days is May (13.8 days).

Average UV index in September - Riley, KS
  • Average UV index in September: 5

The month with the highest UV index is June (UV index 7).
Months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in September - Riley, KS
  • Average cloud cover in September: 26

The month with the most cloud cover is March (Cloud cover 41).
The month with the least cloud cover is June (Cloud cover 22).

Average visibility in September - Riley, KS
  • Average visibility in September: 6mi

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