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
Transition into September subtly marks a drop in the average high-temperature, moderately moving from a moderately hot 78.6°F (25.9°C) in August to a pleasant 71.8°F (22.1°C). Throughout September, the temperature falls to an average low of 52.2°F (11.2°C).Humidity
The average relative humidity in September in Harpers Ferry is 80%.Rainfall
In Harpers Ferry, Iowa, in September, during 10.8 rainfall days, 1.97" (50mm) of precipitation is typically accumulated. In Harpers Ferry, during the entire year, the rain falls for 124.7 days and collects up to 22.56" (573mm) of precipitation.Snowfall
In Harpers Ferry, Iowa, snow does not fall in June through September.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:39 pm. On the last day of September, sunrise is at 7:01 am and sunset at 6:46 pm CDT.
Sunshine
In Harpers Ferry, the average sunshine in September is 8.9h.UV index
In Harpers Ferry, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.Note: The UV index of 4 during September translates into the following guidance:
Take necessary precautions - Suggestions to elude sunburn are provided. Direct exposure to the Sun during its peak hours around mid-day should be minimized for safety. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Harpers Ferry in September?
What is the average humidity in September in Harpers Ferry?
How much does it rain in Harpers Ferry in September?
When it does not snow in Harpers Ferry?
Does it snow in Harpers Ferry in September?
What is the average length of the day in September in Harpers Ferry?
When is the sunrise / sunset in September in Harpers Ferry?
How many hours of sunshine does Harpers Ferry have in September?
What is the UV index intensity in September in Harpers Ferry?
Average temperature in September
Harpers Ferry, IA
- Average high temperature in September: 71.8°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (23.2°F).
- Average low temperature in September: 52.2°F
The month with the highest average low temperature is July (61.9°F).
The coldest month (with the lowest average low temperature) is January (10.6°F).
Average pressure in September
Harpers Ferry, 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
Harpers Ferry, IA
- Average wind speed in September: 7.5mph
The windiest month (with the highest average wind speed) is April (9.9mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).
Average humidity in September
Harpers Ferry, IA
- Average humidity in September: 80%
The months with the highest relative humidity are January and February (88%).
The month with the lowest relative humidity is October (76%).
Average rainfall in September
Harpers Ferry, IA
- Average rainfall in September: 1.97"
The wettest month (with the highest rainfall) is June (3.9").
The driest month (with the least rainfall) is January (0.75").
Average rainfall days in September
Harpers Ferry, IA
- Average rainfall days in September: 10.8 days
The month with the highest number of rainy days is June (18.6 days).
The month with the least rainy days is February (3.6 days).
Average snowfall in September
Harpers Ferry, IA
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.94").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Harpers Ferry, IA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Harpers Ferry, 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 0min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).
Average sunshine days in September
Harpers Ferry, IA
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is November (19.4 days).
The month with the least sunshine days is June (9.6 days).
Average UV index in September
Harpers Ferry, IA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in September
Harpers Ferry, IA
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in September
Harpers Ferry, IA
- Average visibility in September: 5mi
The months with the highest visibility are March, April, May, June, October, November and December (6mi).
The months with the lowest visibility are January, February, July, August and September (5mi).
Harpers Ferry, Iowa, USA
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