September weather forecastSan Luis, AZ
September
Weather in September
September in San Luis, Arizona sees temperatures easing from summer's peak to slightly cooler digits. With limited rainfall and a comparatively low relative humidity, the city maintains an arid environment. Changes in temperature point towards the onset of the fall season. Though the weather remains hot, evening temperatures provide some relief from high daytime temperatures. To sum it up, September represents a step towards a more comfortable climate after the dry and hot summer.Temperature
Transition into September subtly marks a drop in the average high-temperature, moderately moving from a blisteringly hot 105.8°F (41°C) in August to a sweltering 99.7°F (37.6°C). During September, the nighttime temperature averages to a warm 80.6°F (27°C).Humidity
In September, the average relative humidity is 30%.Rainfall
In San Luis, in September, during 3.3 rainfall days, 0.24" (6mm) of precipitation is typically accumulated. Throughout the year, there are 25 rainfall days, and 2.24" (57mm) of precipitation is accumulated.Daylight
In September, the average length of the day is 12h and 21min.On the first day of September, sunrise is at 6:14 am and sunset at 7:03 pm. On the last day of the month, sunrise is at 6:33 am and sunset at 6:24 pm MST.
Sunshine
In San Luis, the average sunshine in September is 9.8h.UV index
June through September, with an average maximum UV index of 8, are months with the highest UV index. A UV Index estimate of 8 to 10 represents a very high health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: In September, the maximum UV index of 8 suggests these recommendations:
Take all necessary measures. Eyes and skin are at risk if left unprotected. Limit your exposure to the sun's UV radiation, which is strongest between 10 a.m. and 4 p.m., and note that parasols or canopies may not provide full sun protection. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
San Luis, AZ
- Average high temperature in September: 99.7°F
The warmest month (with the highest average high temperature) is July (106.2°F).
The month with the lowest average high temperature is December (67.1°F).
- Average low temperature in September: 80.6°F
The month with the highest average low temperature is August (86.2°F).
The coldest month (with the lowest average low temperature) is December (50.5°F).
Average pressure in September
San Luis, AZ
- Average pressure in September: 29.79"Hg
The month with the highest atmospheric pressure is January (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.75"Hg).
Average wind speed in September
San Luis, AZ
- Average wind speed in September: 6.9mph
The windiest month (with the highest average wind speed) is July (8.5mph).
The calmest month (with the lowest average wind speed) is November (6.7mph).
Average humidity in September
San Luis, AZ
- Average humidity in September: 30%
The month with the highest relative humidity is December (38%).
The month with the lowest relative humidity is June (23%).
Average rainfall in September
San Luis, AZ
- Average rainfall in September: 0.24"
The wettest month (with the highest rainfall) is July (0.39").
The driest month (with the least rainfall) is May (0").
Average rainfall days in September
San Luis, AZ
- Average rainfall days in September: 3.3 days
The month with the highest number of rainy days is July (5.1 days).
The month with the least rainy days is May (0.3 days).
Average daylight in September /
Average sunshine in September
San Luis, AZ
- Average daylight in September: 12h and 24min
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 6min).
- Average sunshine in September: 9h and 48min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 7h and 6min).
Average sunshine days in September
San Luis, AZ
- Average sunshine days in September: 26.1 days
The month with the most sunshine days is May (30.4 days).
The month with the least sunshine days is July (24.3 days).
Average UV index in September
San Luis, AZ
- Average UV index in September: 8
The months with the highest UV index are June, July, August and September (UV index 8).
The month with the lowest UV index is December (UV index 4).
Average cloud cover in September
San Luis, AZ
- Average cloud cover in September: 8
The month with the most cloud cover is December (Cloud cover 18).
The month with the least cloud cover is June (Cloud cover 5).
Average visibility in September
San Luis, 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).
