September weather forecastMountain Valley, AR
September
Weather in September
September, the first month of the autumn in Mountain Valley, is still a warm month, with an average temperature varying between 84.9°F (29.4°C) and 63.3°F (17.4°C).Temperature
The transition to September results in a modest reduction in average high-temperature, moving from a hot 91.2°F (32.9°C) in August to a warm 84.9°F (29.4°C). Mountain Valley logs a notable disparity from the daily highs during September, as the nighttime temperature lowers to an average of 63.3°F (17.4°C).Heat index
In September, the average heat index is calculated to be a hot 93.2°F (34°C). Greater preventive actions are needed, heat exhaustion and heat cramps are likely. Persistent activity could provoke heatstroke.One should be cognizant that the heat index values are tailored for shaded spots and mild winds. Direct sunlight exposure may cause a 15 Fahrenheit (8 Celsius) degrees rise in the heat index.
Note: The heat index, also known as 'real feel' or 'felt air temperature', quantifies the warmth felt when relative humidity is considered. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. It is essential to realize that direct sunlight can escalate the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
Humidity
The average relative humidity in September is 73%.Rainfall
September is the month with the least rainfall. Rain falls for 13.2 days and accumulates 2.17" (55mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 23min.On the first day of the month, sunrise is at 6:45 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:06 am and sunset at 6:57 pm CDT.
Sunshine
The average sunshine in September is 9.4h.UV index
The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The maximum UV index of 5 during September leads to these instructions:
Take necessary precautions - Suggestions to elude sunburn are provided. To guard against the harmful effects of the Sun, minimize exposure during midday. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mountain Valley, AR
- Average high temperature in September: 84.9°F
The warmest month (with the highest average high temperature) is July (91.9°F).
The month with the lowest average high temperature is January (48.7°F).
- Average low temperature in September: 63.3°F
The month with the highest average low temperature is July (70.5°F).
The coldest month (with the lowest average low temperature) is January (33.1°F).
Average pressure in September
Mountain Valley, AR
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Mountain Valley, AR
- Average wind speed in September: 4.7mph
The windiest month (with the highest average wind speed) is April (7.4mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in September
Mountain Valley, AR
- Average humidity in September: 73%
The month with the highest relative humidity is March (80%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Mountain Valley, AR
- Average rainfall in September: 2.17"
The wettest month (with the highest rainfall) is April (4.53").
The driest month (with the least rainfall) is September (2.17").
Average rainfall days in September
Mountain Valley, AR
- Average rainfall days in September: 13.2 days
The month with the highest number of rainy days is July (17.3 days).
The month with the least rainy days is November (10.2 days).
Average snowfall in September
Mountain Valley, AR
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.26").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Mountain Valley, AR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.5 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Mountain Valley, AR
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 9h and 24min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).
Average sunshine days in September
Mountain Valley, AR
- Average sunshine days in September: 15.5 days
The month with the most sunshine days is October (18.5 days).
The month with the least sunshine days is July (11.8 days).
Average UV index in September
Mountain Valley, AR
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 7).
The month with the lowest UV index is December (UV index 2).
Average cloud cover in September
Mountain Valley, AR
- Average cloud cover in September: 29
The months with the most cloud cover are February and March (Cloud cover 47).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).
Average visibility in September
Mountain Valley, AR
- Average visibility in September: 6mi
The months with the highest visibility are April, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February, March, May and December (5mi).
