September weather forecastHartley, IA
September
Weather in September
September, the first month of the autumn in Hartley, is still a pleasant month, with temperature in the range of an average low of 53.8°F (12.1°C) and an average high of 73°F (22.8°C).Temperature
The start of September comes with a small reduction in the average high-temperature, subtly receding from a warm 78.6°F (25.9°C) in August to an agreeable 73°F (22.8°C). During the nights in September, an average low-temperature of 53.8°F (12.1°C) is observed.Humidity
In Hartley, the average relative humidity in September is 73%.Rainfall
In Hartley, in September, during 9.2 rainfall days, 0.79" (20mm) of precipitation is typically accumulated. In Hartley, during the entire year, the rain falls for 95.2 days and collects up to 9.25" (235mm) of precipitation.Snowfall
In Hartley, snow does not fall in June through September.Daylight
In Hartley, the average length of the day in September is 12h and 29min.On the first day of September in Hartley, sunrise is at 6:47 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 7:04 pm CDT.
Sunshine
In Hartley, the average sunshine in September is 9h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 4 in September translates into these instructions:
Make use of precautions - It is urged to ward off sun damage. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Hartley, IA
- Average high temperature in September: 73°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (22.8°F).
- Average low temperature in September: 53.8°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (9.9°F).
Average pressure in September
Hartley, IA
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Hartley, IA
- Average wind speed in September: 9.2mph
The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is July (7.8mph).
Average humidity in September
Hartley, IA
- Average humidity in September: 73%
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is October (68%).
Average rainfall in September
Hartley, IA
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is May (1.46").
The driest month (with the least rainfall) is January (0.28").
Average rainfall days in September
Hartley, IA
- Average rainfall days in September: 9.2 days
The month with the highest number of rainy days is June (14.2 days).
The month with the least rainy days is February (2 days).
Average snowfall in September
Hartley, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.77").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Hartley, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Hartley, IA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in September
Hartley, IA
- Average sunshine days in September: 18.5 days
The month with the most sunshine days is December (22.2 days).
The month with the least sunshine days is June (12.6 days).
Average UV index in September
Hartley, IA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February and November (UV index 1).
Average cloud cover in September
Hartley, IA
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in September
Hartley, IA
- 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).





