September weather forecastMystic, IA
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Mystic, Iowa, with an average temperature varying between 56.5°F (13.6°C) and 76.1°F (24.5°C).Temperature
A mild drop in Mystic's average high-temperature is observed in September, transitioning from 82°F (27.8°C) in August to a still warm 76.1°F (24.5°C). Mystic, during September, witnesses an average low-temperature of 56.5°F (13.6°C).Humidity
The average relative humidity in September is 77%.Rainfall
In September, the rain falls for 12.1 days. Throughout September, 2.8" (71mm) of precipitation is accumulated. Throughout the year, there are 143.2 rainfall days, and 27.48" (698mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 27min.On the first day of September in Mystic, sunrise is at 6:39 am and sunset at 7:43 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:54 pm CDT.
Sunshine
The average sunshine in September in Mystic is 9.4h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for the ordinary person.Note: In September, the maximum UV index of 4 suggests these recommendations:
Be vigilant - Suggestions to stave off sun damage are provided. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mystic, IA
- Average high temperature in September: 76.1°F
The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (16.5°F).
Average pressure in September
Mystic, IA
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Mystic, IA
- Average wind speed in September: 8mph
The windiest months (with the highest average wind speed) are January, February and March (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in September
Mystic, IA
- Average humidity in September: 77%
The month with the highest relative humidity is June (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Mystic, IA
- Average rainfall in September: 2.8"
The wettest month (with the highest rainfall) is June (3.98").
The driest month (with the least rainfall) is January (1.02").
Average rainfall days in September
Mystic, IA
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is January (5 days).
Average snowfall in September
Mystic, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (4.33").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Mystic, 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
Mystic, IA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 9h and 24min
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 18min).
Average sunshine days in September
Mystic, IA
- Average sunshine days in September: 15.7 days
The month with the most sunshine days is November (18.6 days).
The month with the least sunshine days is June (8.8 days).
Average UV index in September
Mystic, IA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Mystic, IA
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 53).
The months with the least cloud cover are July, August and September (Cloud cover 29).
Average visibility in September
Mystic, 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).





