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
The arrival of September records an average high-temperature of a moderately hot 83.7°F (28.7°C), closely related to the 87.1°F (30.6°C) observed in August. During September, the average low-temperature is a comfortable 64.6°F (18.1°C).Heat index
September's mean heat index is estimated at 84.2°F (29°C). Extended exposure and activity might lead to tiredness, potentially resulting in heat cramps.In the scope of the heat index, its values resonate with shade and light wind conditions. Direct sunlight might cause an increase of up to 15 Fahrenheit (8 Celsius) degrees in the heat index.
Note: The heat index, also known as 'felt air temperature' or 'real feel', combines air temperature and relative humidity to represent a human perceived temperature equivalent. A person's impression of weather can be affected by numerous aspects, among them metabolic variations, pregnancy, and activity levels. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Young ones often disregard the necessity to rest and hydrate. Thirst usually indicates advanced dehydration - hence, it is key to stay hydrated, particularly during ongoing physical activities.
Humidity
The average relative humidity in September in Alto is 50%.Rainfall
In Alto, in September, it is raining for 12.2 days, with typically 2.32" (59mm) of accumulated precipitation. In Alto, Arizona, during the entire year, the rain falls for 87.8 days and collects up to 15.43" (392mm) of precipitation.Snowfall
April through November are months without snowfall.Daylight
In September, the average length of the day is 12h and 21min.On the first day of September in Alto, sunrise is at 5:59 am and sunset at 6:46 pm. On the last day of the month, sunrise is at 6:17 am and sunset at 6:09 pm MST.
Sunshine
The average sunshine in September is 9.6h.UV index
The average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high threat to health from unprotected exposure to Sun's UV rays for the average person.Note: The daily maximum UV index of 6 in September interprets into the following advice:
Resist overexposure. Safeguarding from solar damage is indispensable. UV radiation from the sun is at its strongest between 10 a.m. and 4 p.m. Try to limit direct exposure during these hours. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Alto, AZ
- Average high temperature in September: 83.7°F
The warmest month (with the highest average high temperature) is June (91°F).
The month with the lowest average high temperature is December (59.2°F).
- Average low temperature in September: 64.6°F
The month with the highest average low temperature is July (70.2°F).
The coldest month (with the lowest average low temperature) is December (39.9°F).
Average pressure in September
Alto, AZ
- Average pressure in September: 29.87"Hg
The month with the highest atmospheric pressure is January (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.82"Hg).
Average wind speed in September
Alto, AZ
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is May (9.9mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in September
Alto, AZ
- Average humidity in September: 50%
The month with the highest relative humidity is August (51%).
The months with the lowest relative humidity are May and June (24%).
Average rainfall in September
Alto, AZ
- Average rainfall in September: 2.32"
The wettest month (with the highest rainfall) is July (4.53").
The driest month (with the least rainfall) is May (0.16").
Average rainfall days in September
Alto, AZ
- Average rainfall days in September: 12.2 days
The month with the highest number of rainy days is July (21.9 days).
The month with the least rainy days is May (1.8 days).
Average snowfall in September
Alto, AZ
- Average snowfall in September: 0"
The month with the highest snowfall is December (1.06").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Alto, AZ
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.8 days).
The months with the least snowfall days are April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
Alto, AZ
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 12min).
The month with the shortest days is December (Average daylight: 10h and 6min).
- Average sunshine in September: 9h and 4min
The month with the most sunshine is June (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 54min).
Average sunshine days in September
Alto, AZ
- Average sunshine days in September: 15 days
The month with the most sunshine days is May (28.8 days).
The month with the least sunshine days is July (6.6 days).
Average UV index in September
Alto, AZ
- Average UV index in September: 6
The months with the highest UV index are June and August (UV index 7).
The months with the lowest UV index are January, November and December (UV index 3).
Average cloud cover in September
Alto, AZ
- Average cloud cover in September: 17
The month with the most cloud cover is July (Cloud cover 24).
The month with the least cloud cover is May (Cloud cover 7).
Average visibility in September
Alto, AZ
- 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).
Alto, Arizona, USA
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