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 Mountain Brook, Alabama, transitions into September, the average high-temperature stands at a moderately hot 84.9°F (29.4°C), offering little variation from the preceding month. Mountain Brook reports an average low-temperature of 65.3°F (18.5°C) during the nights of September.Heat index
The heat index value during September is appraised at a tropical 93.2°F (34°C). Undertake enhanced precautions, heat exhaustion and heat cramps are possible risks. Continuous activity could trigger heatstroke.Evaluating the heat index requires understanding its values in the shade and with gentle winds. Direct exposure to sunlight could raise the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', joins air temperature with relative humidity to produce a temperature perception for humans. This effect tends to be personal, with the weather perception differing among individuals due to variations in body mass, height, and exertion. When in direct sunlight, one should be cautious as it can raise the heat index by as much as 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for babies and toddlers. Youngsters frequently overlook the need for breaks and fluid intake. Thirst is an advanced sign of dehydration - thereby highlighting the importance of keeping hydrated, particularly during long physical activities.
Humidity
The average relative humidity in September is 72%.Rainfall
In September, in Mountain Brook, the rain falls for 12.1 days. Throughout September, 1.1" (28mm) of precipitation is accumulated. In Mountain Brook, during the entire year, the rain falls for 143.1 days and collects up to 18.58" (472mm) of precipitation.Snowfall
In Mountain Brook, snow does not fall in April through October.Daylight
The average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:21 am and sunset at 7:11 pm. On the last day of September, sunrise is at 6:41 am and sunset at 6:32 pm CDT.
Sunshine
In Mountain Brook, the average sunshine in September is 8.8h.UV index
In September, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for average individuals.Note: In September, the maximum UV index of 5 translates into these guidelines:
Prioritize safety - Suggestions to prevent sun damage are offered. Around midday, solar radiation is most harmful; hence, exposure should be limited. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Frequently asked questions
How hot is September in Mountain Brook?
What is the average humidity in September in Mountain Brook?
How many days does it rain in September in Mountain Brook?
When it does not snow in Mountain Brook?
What is the average length of the day in September in Mountain Brook?
What time are sunrise and sunset in September in Mountain Brook?
How long on average sun shines in September in Mountain Brook?
What is the UV index reading in September in Mountain Brook?
Average temperature in September
Mountain Brook, AL
- Average high temperature in September: 84.9°F
The warmest month (with the highest average high temperature) is July (91°F).
The month with the lowest average high temperature is January (50.7°F).
- Average low temperature in September: 65.3°F
The month with the highest average low temperature is July (71.1°F).
The coldest month (with the lowest average low temperature) is January (35.2°F).
Average pressure in September
Mountain Brook, AL
- 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 (29.98"Hg).
Average wind speed in September
Mountain Brook, AL
- Average wind speed in September: 4.8mph
The windiest month (with the highest average wind speed) is February (7.4mph).
The calmest months (with the lowest average wind speed) are July and August (4.5mph).
Average humidity in September
Mountain Brook, AL
- Average humidity in September: 72%
The month with the highest relative humidity is December (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Mountain Brook, AL
- Average rainfall in September: 1.1"
The wettest month (with the highest rainfall) is June (1.97").
The driest month (with the least rainfall) is November (1.02").
Average rainfall days in September
Mountain Brook, AL
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is November (7.9 days).
Average snowfall in September
Mountain Brook, AL
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.12").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Mountain Brook, AL
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (0.8 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 Brook, AL
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in September
Mountain Brook, AL
- Average sunshine days in September: 15.7 days
The month with the most sunshine days is October (20.9 days).
The month with the least sunshine days is July (11.1 days).
Average UV index in September
Mountain Brook, AL
- Average UV index in September: 5
The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is December (UV index 2).
Average cloud cover in September
Mountain Brook, AL
- Average cloud cover in September: 30
The month with the most cloud cover is February (Cloud cover 48).
The months with the least cloud cover are June and September (Cloud cover 30).
Average visibility in September
Mountain Brook, AL
- 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).
Mountain Brook, Alabama, USA
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