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
Mason City marks the start of September with an average high-temperature of a pleasant 72.3°F (22.4°C), hinting at a slight fluctuation from August's 77.4°F (25.2°C). During the month of September, the temperature falls to an average of 53.8°F (12.1°C).Humidity
In September, the average relative humidity is 78%.Rainfall
In September, the rain falls for 12.5 days. Throughout September, 2.52" (64mm) of precipitation is accumulated. Throughout the year, there are 145.9 rainfall days, and 28.82" (732mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day in Mason City is 12h and 29min.On the first day of September, sunrise is at 6:37 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:09 am and sunset at 6:55 pm CDT.
Sunshine
In Mason City, the average sunshine in September is 9h.UV index
In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.Note: An average UV index of 4 in September transforms into this advice:
Take necessary precautions - Protection from skin and eye injury is mandatory. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Stay sun-safe with clothing that is both closely woven and worn loosely.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Mason City have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Mason City have in September?
What is the UV index intensity in September?
Average temperature in September
Mason City, IA
- Average high temperature in September: 72.3°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (22.3°F).
- Average low temperature in September: 53.8°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (9.9°F).
Average pressure in September
Mason City, IA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Mason City, IA
- Average wind speed in September: 8.5mph
The windiest months (with the highest average wind speed) are January and April (10.9mph).
The calmest months (with the lowest average wind speed) are July and August (7.3mph).
Average humidity in September
Mason City, IA
- Average humidity in September: 78%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Mason City, IA
- Average rainfall in September: 2.52"
The wettest month (with the highest rainfall) is June (4.65").
The driest month (with the least rainfall) is January (1.06").
Average rainfall days in September
Mason City, IA
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is June (19.8 days).
The month with the least rainy days is February (3.8 days).
Average snowfall in September
Mason City, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (7.48").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Mason City, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (14.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Mason City, IA
- Average daylight in September: 12h and 3min
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: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in September
Mason City, IA
- Average sunshine days in September: 15.1 days
The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is June (8 days).
Average UV index in September
Mason City, IA
- Average UV index in September: 4
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Mason City, IA
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in September
Mason City, IA
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, August, September, October and November (6mi).
The months with the lowest visibility are January, February, July and December (5mi).
Mason City, Iowa, USA
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