September weather forecastHelena, MO
September
Weather in September
The first month of the autumn, September, is still a warm month in Helena, Missouri, with an average temperature ranging between max 77.5°F (25.3°C) and min 57.9°F (14.4°C).Temperature
The onset of September aligns with a soft reduction in the average high-temperature, gently falling from 83.8°F (28.8°C) in August to a still warm 77.5°F (25.3°C). An average low-temperature of 57.9°F (14.4°C) is recorded during the nights in September.Humidity
The average relative humidity in September is 75%.Rainfall
In Helena, during September, the rain falls for 12.2 days and regularly aggregates up to 2.4" (61mm) of precipitation. In Helena, during the entire year, the rain falls for 132.3 days and collects up to 27.28" (693mm) of precipitation.Snowfall
In Helena, Missouri, snow does not fall in June through September.Daylight
In September, the average length of the day in Helena is 12h and 26min.On the first day of September in Helena, sunrise is at 6:47 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:14 am and sunset at 7:02 pm CDT.
Sunshine
In Helena, the average sunshine in September is 9.3h.UV index
In Helena, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 5 during September translates into these guidelines:
Put precautions into practice - Ensuring skin and eye safety is a necessity. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Helena, MO
- Average high temperature in September: 77.5°F
The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is January (34.2°F).
- Average low temperature in September: 57.9°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (20.3°F).
Average pressure in September
Helena, MO
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Helena, MO
- Average wind speed in September: 7.4mph
The windiest months (with the highest average wind speed) are February and March (9.9mph).
The calmest month (with the lowest average wind speed) is July (6.4mph).
Average humidity in September
Helena, MO
- Average humidity in September: 75%
The month with the highest relative humidity is June (79%).
The months with the lowest relative humidity are October and November (70%).
Average rainfall in September
Helena, MO
- Average rainfall in September: 2.4"
The wettest month (with the highest rainfall) is May (4.02").
The driest months (with the least rainfall) are January and February (0.94").
Average rainfall days in September
Helena, MO
- Average rainfall days in September: 12.2 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (3.8 days).
Average snowfall in September
Helena, MO
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.43").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Helena, MO
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (7.2 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, MO
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 9h and 18min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 48min).
Average sunshine days in September
Helena, MO
- Average sunshine days in September: 16.3 days
The month with the most sunshine days is November (21.1 days).
The month with the least sunshine days is June (10.8 days).
Average UV index in September
Helena, MO
- 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
Helena, MO
- Average cloud cover in September: 29
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 27).
Average visibility in September
Helena, MO
- 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).
