Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September's arrival subtly correlates with a reduction in the average high-temperature, down from a hot 89.2°F (31.8°C) in August to a warm 81.9°F (27.7°C). Throughout September, Grinnell's nights cool down to an average of 60.4°F (15.8°C).Heat index
September's mean heat index is estimated at 82.4°F (28°C). Continuous activity in exposure could lead to a feeling of fatigue and heat cramps.Heat index details are generally centered around shaded locations and a mild breeze. Heat index values have the potential to be boosted by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'real feel' or 'felt air temperature', gives a temperature feeling by integrating air temperature and humidity. Metabolic differences, pregnancy status, and the level of physical activity are additional factors influencing an individual's weather perception. Consider the fact that direct sun exposure can influence how hot one feels, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are essentially critical for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
Humidity
In Grinnell, Kansas, the average relative humidity in September is 53%.Rainfall
In Grinnell, during September, the rain falls for 9.5 days and regularly aggregates up to 1.1" (28mm) of precipitation. Throughout the year, in Grinnell, there are 105.4 rainfall days, and 13.7" (348mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall in Grinnell.Daylight
In Grinnell, the average length of the day in September is 12h and 26min.On the first day of September in Grinnell, sunrise is at 7:11 am and sunset at 8:12 pm. On the last day of the month, sunrise is at 7:38 am and sunset at 7:26 pm CDT.
Sunshine
In Grinnell, Kansas, the average sunshine in September is 9.2h.UV index
In Grinnell, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum UV index of 5 during September leads to these instructions:
Heed the precautions - It is counselled to guard against solar damage. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Grinnell in September?
What is the average humidity in September in Grinnell?
How many days does it rain in September in Grinnell?
When it does not snow in Grinnell?
Does it snow in Grinnell in September?
What is the average length of the day in September in Grinnell?
When are sunrise and sunset in September in Grinnell?
How long on average sun shines in September in Grinnell?
What is the UV index reading in September in Grinnell?
Average temperature in September
Grinnell, KS
- Average high temperature in September: 81.9°F
The warmest month (with the highest average high temperature) is July (92.5°F).
The month with the lowest average high temperature is December (41.9°F).
- Average low temperature in September: 60.4°F
The month with the highest average low temperature is July (70.3°F).
The coldest month (with the lowest average low temperature) is January (25.2°F).
Average pressure in September
Grinnell, KS
- Average pressure in September: 29.94"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.81"Hg).
Average wind speed in September
Grinnell, KS
- Average wind speed in September: 11.2mph
The windiest month (with the highest average wind speed) is April (12.9mph).
The calmest month (with the lowest average wind speed) is August (10.1mph).
Average humidity in September
Grinnell, KS
- Average humidity in September: 53%
The months with the highest relative humidity are January and December (63%).
The month with the lowest relative humidity is July (50%).
Average rainfall in September
Grinnell, KS
- Average rainfall in September: 1.1"
The wettest month (with the highest rainfall) is May (2.36").
The driest months (with the least rainfall) are January and November (0.39").
Average rainfall days in September
Grinnell, KS
- Average rainfall days in September: 9.5 days
The month with the highest number of rainy days is May (13.4 days).
The month with the least rainy days is November (4 days).
Average snowfall in September
Grinnell, KS
- Average snowfall in September: 0"
The month with the highest snowfall is December (1.06").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Grinnell, KS
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.9 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
Grinnell, KS
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 1min
The months with the most sunshine are June and July (Average sunshine: 11h and 36min).
The month with the least sunshine is December (Average sunshine: 6h and 30min).
Average sunshine days in September
Grinnell, KS
- Average sunshine days in September: 18 days
The month with the most sunshine days is December (23.7 days).
The months with the least sunshine days are June and July (14.7 days).
Average UV index in September
Grinnell, KS
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Grinnell, KS
- Average cloud cover in September: 19
The months with the most cloud cover are February and April (Cloud cover 31).
The month with the least cloud cover is June (Cloud cover 17).
Average visibility in September
Grinnell, KS
- 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).
Grinnell, Kansas, USA
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