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
Transition into September subtly marks a drop in the average high-temperature, moderately moving from a moderately hot 74.8°F (23.8°C) in August to a pleasant 68.5°F (20.3°C). Against the backdrop of high daytime temperatures, an average low-temperature of 43.7°F (6.5°C) is noted during September nights.Humidity
In September, the average relative humidity is 51%.Rainfall
In San Luis, Colorado, during September, the rain falls for 7.1 days and regularly aggregates up to 0.59" (15mm) of precipitation. Throughout the year, there are 72.2 rainfall days, and 8.82" (224mm) of precipitation is accumulated.Snowfall
January through June, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.4 snowfall days, it receives 0.2" (5mm) of snow. In San Luis, during the entire year, snow falls for 57.6 days and aggregates up to 28.58" (726mm) of snow.Daylight
The average length of the day in September is 12h and 25min.On the first day of the month, sunrise is at 6:32 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:56 am and sunset at 6:45 pm MDT.
Sunshine
In September, the average sunshine is 11h.UV index
In San Luis, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for average individuals.Note: The daily maximum UV index of 4 in September interprets into the following advice:
Make use of precautions - It is urged to ward off sun damage. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Be mindful! The reflection from snow can increase the Sun's UV radiation nearly twice.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How much does it rain in September?
When does it start to snow?
How many hours of daylight does San Luis have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does San Luis have in September?
What is the UV index intensity in September?
Average temperature in September
San Luis, CO
- Average high temperature in September: 68.5°F
The warmest month (with the highest average high temperature) is July (76.6°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in September: 43.7°F
The month with the highest average low temperature is July (50.2°F).
The coldest month (with the lowest average low temperature) is January (9.3°F).
Average pressure in September
San Luis, CO
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is April (29.89"Hg).
Average wind speed in September
San Luis, CO
- Average wind speed in September: 6.5mph
The windiest months (with the highest average wind speed) are April and May (8.9mph).
The calmest month (with the lowest average wind speed) is July (5.5mph).
Average humidity in September
San Luis, CO
- Average humidity in September: 51%
The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is June (38%).
Average rainfall in September
San Luis, CO
- Average rainfall in September: 0.59"
The wettest month (with the highest rainfall) is July (1.61").
The driest month (with the least rainfall) is November (0.43").
Average rainfall days in September
San Luis, CO
- Average rainfall days in September: 7.1 days
The month with the highest number of rainy days is July (13.9 days).
The month with the least rainy days is November (1.3 days).
Average snowfall in September
San Luis, CO
- Average snowfall in September: 0.2"
The month with the highest snowfall is March (5.55").
The months with the least snowfall are July and August (0").
Average snowfall days in September
San Luis, CO
- Average snowfall days in September: 0.4 days
The month with the highest number of snowfall days is February (10.1 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
San Luis, CO
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 11h and 0min
The month with the most sunshine is June (Average sunshine: 11h and 48min).
The month with the least sunshine is January (Average sunshine: 6h and 30min).
Average sunshine days in September
San Luis, CO
- Average sunshine days in September: 20.5 days
The month with the most sunshine days is October (24.1 days).
The month with the least sunshine days is July (13.3 days).
Average UV index in September
San Luis, CO
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in September
San Luis, CO
- Average cloud cover in September: 15
The month with the most cloud cover is January (Cloud cover 31).
The months with the least cloud cover are June and October (Cloud cover 14).
Average visibility in September
San Luis, CO
- Average visibility in September: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is January (4mi).
San Luis, Colorado, USA
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