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 ushers in a minute temperature change, with average high-temperatures reducing from August's warm 79.3°F (26.3°C) to a still moderately hot 73.4°F (23°C). In Cass, the average temperature during the nights of September drops to a cool 54.7°F (12.6°C).Humidity
The average relative humidity in September in Cass, Iowa, is 78%.Rainfall
In Cass, Iowa, during September, the rain falls for 11.4 days and regularly aggregates up to 2.52" (64mm) of precipitation. Throughout the year, there are 137.5 rainfall days, and 27.68" (703mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
In September, the average length of the day in Cass is 12h and 28min.On the first day of the month, sunrise is at 6:31 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:02 am and sunset at 6:48 pm CDT.
Sunshine
In Cass, Iowa, the average sunshine in September is 9.2h.UV index
The average daily maximum UV index in September in Cass is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Put precautions into practice - Ensuring skin and eye safety is a necessity. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Cass?
What is the average humidity in September in Cass?
How much does it rain in Cass in September?
When it does not snow in Cass?
Does it snow in Cass in September?
How many hours of daylight does Cass have in September?
When are sunrise and sunset in September in Cass?
How long on average sun shines in September in Cass?
How high is the UV index in September in Cass?
Average temperature in September
Cass, IA
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (25.5°F).
- Average low temperature in September: 54.7°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (13.5°F).
Average pressure in September
Cass, 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
Cass, IA
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in September
Cass, 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
Cass, IA
- Average rainfall in September: 2.52"
The wettest month (with the highest rainfall) is May (4.45").
The driest month (with the least rainfall) is February (1.02").
Average rainfall days in September
Cass, IA
- Average rainfall days in September: 11.4 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is January (4.1 days).
Average snowfall in September
Cass, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.16").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Cass, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Cass, IA
- Average daylight in September: 12h and 3min
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 1min
The months with the most sunshine are July and August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Cass, IA
- Average sunshine days in September: 17.4 days
The month with the most sunshine days is December (18.2 days).
The month with the least sunshine days is May (10.9 days).
Average UV index in September
Cass, IA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Cass, IA
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in September
Cass, IA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
Cass, Iowa, USA
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