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
Waterloo's progression into September involves a gentle drop in the average high-temperature, from a moderately hot 78.6°F (25.9°C) in August to a pleasant 73.2°F (22.9°C). Waterloo observes an average nighttime low-temperature of 54.5°F (12.5°C) during the month of September.Humidity
In September, the average relative humidity is 78%.Rainfall
In Waterloo, in September, it is raining for 11.2 days, with typically 2.48" (63mm) of accumulated precipitation. Throughout the year, in Waterloo, Iowa, there are 133.6 rainfall days, and 28.27" (718mm) of precipitation is accumulated.Snowfall
In Waterloo, Iowa, snow does not fall in June through September.Daylight
The average length of the day in September in Waterloo, Iowa, is 12h and 28min.On the first day of the month, sunrise is at 6:35 am and sunset at 7:43 pm. On the last day of September, in Waterloo, sunrise is at 7:06 am and sunset at 6:51 pm CDT.
Sunshine
In September, the average sunshine in Waterloo is 9.1h.UV index
In Waterloo, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Act with care - The need to guard against sun damage is communicated. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Waterloo in September?
What is the average humidity in September in Waterloo?
How many days does it rain in September in Waterloo?
When it does not snow in Waterloo?
Does it snow in Waterloo in September?
What is the average length of the day in September in Waterloo?
When are sunrise and sunset in September in Waterloo?
How many hours of sunshine does Waterloo have in September?
How high is the UV index in September in Waterloo?
Average temperature in September
Waterloo, IA
- Average high temperature in September: 73.2°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 (24.3°F).
- Average low temperature in September: 54.5°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 (12°F).
Average pressure in September
Waterloo, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Waterloo, IA
- Average wind speed in September: 8.2mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest month (with the lowest average wind speed) is August (7mph).
Average humidity in September
Waterloo, IA
- Average humidity in September: 78%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Waterloo, IA
- Average rainfall in September: 2.48"
The wettest month (with the highest rainfall) is June (4.29").
The driest months (with the least rainfall) are January and February (1.02").
Average rainfall days in September
Waterloo, IA
- Average rainfall days in September: 11.2 days
The month with the highest number of rainy days is June (18.1 days).
The month with the least rainy days is February (4 days).
Average snowfall in September
Waterloo, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.21").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Waterloo, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Waterloo, 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 6min).
- Average sunshine in September: 9h and 1min
The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in September
Waterloo, IA
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is October (17.8 days).
The month with the least sunshine days is June (10 days).
Average UV index in September
Waterloo, IA
- Average UV index in September: 4
The month with the highest UV index is June (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Waterloo, IA
- Average cloud cover in September: 32
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in September
Waterloo, IA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
Waterloo, Iowa, USA
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