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 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
September
Weather in September
Temperature
In Colma, September is the warmest month, with temperatures averaging a high of 69.1°F (20.6°C) and a low of 56.5°F (13.6°C).Humidity
In Colma, the average relative humidity in September is 74%.Rainfall
In Colma, during September, the rain falls for 3 days and regularly aggregates up to 0.16" (4mm) of precipitation. Throughout the year, in Colma, there are 82.2 rainfall days, and 13.62" (346mm) of precipitation is accumulated.Daylight
In September, the average length of the day is 12h and 25min.On the first day of September, sunrise is at 6:40 am and sunset at 7:38 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:53 pm PDT.
Sunshine
The average sunshine in September is 10.7h.UV index
June through September, with an average maximum UV index of 5, are months with the highest UV index. 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 UV index of 5 transforms into the following advice:
Adopt protective measures - It is advised to guard against sun damage. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the warmest month?
What are the temperatures in September?
What is the average humidity in September?
How much does it rain in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Colma have in September?
What are the months with the highest UV index?
What is the UV index intensity in September?
Average temperature in September
Colma, CA
- Average high temperature in September: 69.1°F
The warmest month (with the highest average high temperature) is September (69.1°F).
The month with the lowest average high temperature is December (55.4°F).
- Average low temperature in September: 56.5°F
The month with the highest average low temperature is September (56.5°F).
The coldest month (with the lowest average low temperature) is February (47.7°F).
Average pressure in September
Colma, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are August and September (29.92"Hg).
Average wind speed in September
Colma, CA
- Average wind speed in September: 6.3mph
The windiest month (with the highest average wind speed) is April (8.6mph).
The calmest month (with the lowest average wind speed) is September (6.3mph).
Average humidity in September
Colma, CA
- Average humidity in September: 74%
The month with the highest relative humidity is August (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Colma, CA
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is February (2.8").
The driest months (with the least rainfall) are July and August (0.08").
Average rainfall days in September
Colma, CA
- Average rainfall days in September: 3 days
The month with the highest number of rainy days is March (12.8 days).
The month with the least rainy days is July (2.7 days).
Average daylight in September /
Average sunshine in September
Colma, CA
- 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 36min).
- Average sunshine in September: 10h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 24min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in September
Colma, CA
- Average sunshine days in September: 23.7 days
The month with the most sunshine days is July (25.3 days).
The month with the least sunshine days is March (16.6 days).
Average UV index in September
Colma, CA
- Average UV index in September: 5
The months with the highest UV index are June, July, August and September (UV index 5).
The months with the lowest UV index are February, November and December (UV index 3).
Average cloud cover in September
Colma, CA
- Average cloud cover in September: 18
The month with the most cloud cover is March (Cloud cover 38).
The month with the least cloud cover is September (Cloud cover 18).
Average visibility in September
Colma, CA
- 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).