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
As September commences, the average high-temperature subtly reduces, transitioning from 84.2°F (29°C) in August to a still moderately hot 78.1°F (25.6°C). During the month of September, Helena's nighttime temperature lowers to an average of 57.7°F (14.3°C).Humidity
In September, the average relative humidity is 76%.Rainfall
The months with the least rainfall are January, September and October Rain falls for 10.2 days and accumulates 1.06" (27mm) of rain.Snowfall
In Helena, snow does not fall in May through September.Daylight
The average length of the day in September is 12h and 25min.On the first day of September, sunrise is at 7:05 am and sunset at 8:04 pm. On the last day of the month, sunrise is at 7:30 am and sunset at 7:19 pm EDT.
Sunshine
In Helena, the average sunshine in September is 8.3h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: An average maximum UV index of 4 in September leads to these recommendations:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures in Helena?
What is the average humidity in September in Helena?
What is the driest month in Helena?
How much does it rain in Helena in September?
When it does not snow in Helena?
Does it snow in Helena in September?
What is the average length of the day in September in Helena?
When are sunrise and sunset in September in Helena?
How many hours of sunshine does Helena have in September?
What is the UV index reading in September in Helena?
Average temperature in September
Helena, KY
- Average high temperature in September: 78.1°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is January (37.9°F).
- Average low temperature in September: 57.7°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (25.2°F).
Average pressure in September
Helena, KY
- Average pressure in September: 30.04"Hg
The months with the highest atmospheric pressure are January and November (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.96"Hg).
Average wind speed in September
Helena, KY
- Average wind speed in September: 5.4mph
The windiest month (with the highest average wind speed) is January (8.5mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in September
Helena, KY
- Average humidity in September: 76%
The months with the highest relative humidity are February and December (81%).
The month with the lowest relative humidity is August (75%).
Average rainfall in September
Helena, KY
- Average rainfall in September: 1.06"
The wettest month (with the highest rainfall) is July (1.93").
The driest months (with the least rainfall) are January, September and October (1.06").
Average rainfall days in September
Helena, KY
- Average rainfall days in September: 10.2 days
The month with the highest number of rainy days is July (15.8 days).
The month with the least rainy days is November (8.3 days).
Average snowfall in September
Helena, KY
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.46").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Helena, KY
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Helena, KY
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 8h and 2min
The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Helena, KY
- Average sunshine days in September: 17.7 days
The month with the most sunshine days is November (19 days).
The month with the least sunshine days is February (11.4 days).
Average UV index in September
Helena, KY
- Average UV index in September: 4
The months with the highest UV index are May, 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
Helena, KY
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Helena, KY
- Average visibility in September: 5mi
The months with the highest visibility are March, April, June, August, October, November and December (6mi).
The months with the lowest visibility are January, February, May, July and September (5mi).
Helena, Kentucky, USA
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