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
Bethesda's September weather features a light decline in high-temperatures, reducing from a warm 82.2°F (27.9°C) in August to a still moderately hot 76.6°F (24.8°C). Bethesda's September nights cool down to an average low-temperature of 57°F (13.9°C).Humidity
The average relative humidity in September is 75%.Rainfall
In Bethesda, during September, the rain falls for 10.1 days and regularly aggregates up to 1.34" (34mm) of precipitation. Throughout the year, there are 114.9 rainfall days, and 18.39" (467mm) of precipitation is accumulated.Snowfall
In Bethesda, snow does not fall in May through September.Daylight
In September, the average length of the day is 12h and 27min.On the first day of the month, sunrise is at 6:48 am and sunset at 7:52 pm. On the last day of September, sunrise is at 7:16 am and sunset at 7:03 pm CDT.
Sunshine
The average sunshine in September is 9.3h.UV index
In Bethesda, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for average individuals.Note: In September, a regular UV index of 5 translates into these guidelines:
Guard yourself - Precautionary measures against sun damage are advocated. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
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 Bethesda have in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Bethesda, IA
- Average high temperature in September: 76.6°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (31.1°F).
- Average low temperature in September: 57°F
The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (17.2°F).
Average pressure in September
Bethesda, IA
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
Bethesda, IA
- Average wind speed in September: 8mph
The windiest month (with the highest average wind speed) is March (10.3mph).
The calmest month (with the lowest average wind speed) is July (6.7mph).
Average humidity in September
Bethesda, IA
- Average humidity in September: 75%
The month with the highest relative humidity is January (80%).
The month with the lowest relative humidity is October (69%).
Average rainfall in September
Bethesda, IA
- Average rainfall in September: 1.34"
The wettest month (with the highest rainfall) is June (3.39").
The driest month (with the least rainfall) is February (0.43").
Average rainfall days in September
Bethesda, IA
- Average rainfall days in September: 10.1 days
The month with the highest number of rainy days is May (16.7 days).
The month with the least rainy days is February (3.4 days).
Average snowfall in September
Bethesda, IA
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.17").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Bethesda, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Bethesda, IA
- Average daylight in September: 12h and 3min
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 2min
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 36min).
Average sunshine days in September
Bethesda, IA
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is November (22.5 days).
The month with the least sunshine days is June (12.3 days).
Average UV index in September
Bethesda, IA
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Bethesda, IA
- Average cloud cover in September: 28
The month with the most cloud cover is January (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 27).
Average visibility in September
Bethesda, 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).
Bethesda, Iowa, USA
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