September weather forecastDelmar, IA
September
Weather in September
The first month of the autumn, September, is still a warm month in Delmar, Iowa, with an average temperature ranging between max 73.6°F (23.1°C) and min 54.5°F (12.5°C).Temperature
As August transitions into September, Delmar sees a gentle drop in the average high-temperature, transitioning from 79.3°F (26.3°C) to a still warm 73.6°F (23.1°C). During the month of September, the temperature generally drops to a low average of 54.5°F (12.5°C).Humidity
In Delmar, the average relative humidity in September is 78%.Rainfall
In September, the rain falls for 11.6 days. Throughout September, 2.44" (62mm) of precipitation is accumulated. In Delmar, during the entire year, the rain falls for 143.3 days and collects up to 29.76" (756mm) of precipitation.Snowfall
In Delmar, snow does not fall in May through September.Daylight
In September, the average length of the day is 12h and 28min.On the first day of September in Delmar, sunrise is at 6:28 am and sunset at 7:35 pm. On the last day of the month, sunrise is at 6:59 am and sunset at 6:45 pm CDT.
Sunshine
In Delmar, the average sunshine in September is 9.2h.UV index
In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for the average person.Note: In September, a regular UV index of 4 translates into these guidelines:
Guard yourself - Avoiding sunburn is suggested. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Delmar, IA
- Average high temperature in September: 73.6°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 (25.9°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (63.7°F).
The coldest month (with the lowest average low temperature) is January (13.3°F).
Average pressure in September
Delmar, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Delmar, IA
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is April (10.5mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity in September
Delmar, IA
- Average humidity in September: 78%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Delmar, IA
- Average rainfall in September: 2.44"
The wettest month (with the highest rainfall) is May (4.53").
The driest month (with the least rainfall) is January (1.34").
Average rainfall days in September
Delmar, IA
- Average rainfall days in September: 11.6 days
The month with the highest number of rainy days is May (18.7 days).
The month with the least rainy days is February (5.3 days).
Average snowfall in September
Delmar, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.2").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Delmar, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11 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
Delmar, IA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 9h and 12min
The month with the most sunshine is July (Average sunshine: 9h and 54min).
The months with the least sunshine are January and February (Average sunshine: 3h and 54min).
Average sunshine days in September
Delmar, IA
- Average sunshine days in September: 16.3 days
The month with the most sunshine days is November (18.6 days).
The month with the least sunshine days is May (10.2 days).
Average UV index in September
Delmar, IA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Delmar, IA
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are August and September (Cloud cover 31).
Average visibility in September
Delmar, IA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January and July (5mi).





