September weather forecastBarstow, CA

September
Weather in September
The first month of the autumn, September, is still a tropical month in Barstow, California, with an average temperature fluctuating between 88.3°F (31.3°C) and 67.3°F (19.6°C).Temperature
The start of September involves a subtle temperature drop, shifting from a very hot 95.4°F (35.2°C) in August to a tropical 88.3°F (31.3°C). Barstow experiences an average low-temperature of 67.3°F (19.6°C) in the month of September.Humidity
The average relative humidity in September is 27%.Rainfall
In Barstow, in September, it is raining for 1.9 days, with typically 0.08" (2mm) of accumulated precipitation. Throughout the year, there are 36.5 rainfall days, and 3.11" (79mm) of precipitation is accumulated.Snowfall
In Barstow, snow does not fall in February through October and December.Daylight
In Barstow, the average length of the day in September is 12h and 23min.On the first day of September, sunrise is at 6:21 am and sunset at 7:14 pm. On the last day of the month, sunrise is at 6:42 am and sunset at 6:32 pm PDT.
Sunshine
The average sunshine in September is 10.7h.UV index
The average daily maximum UV index in September is 6. A UV Index reading of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV rays for the ordinary person.Note: The maximum UV index, 6 during September, leads to the following recommendations:
Implement preventive steps and embrace sun safety standards. Protection from skin and eye distress is compulsory. The Sun's UV radiation is most potent between the hours of 10 a.m. and 4 p.m. Try to avoid direct sunlight during this time. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Barstow, CA
- Average high temperature in September: 88.3°F
The warmest month (with the highest average high temperature) is July (96.4°F).
The month with the lowest average high temperature is December (54.3°F).
- Average low temperature in September: 67.3°F
The month with the highest average low temperature is August (72.9°F).
The coldest month (with the lowest average low temperature) is December (38.7°F).
Average pressure in September
Barstow, CA
- Average pressure in September: 29.85"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.81"Hg).
Average wind speed in September
Barstow, CA
- Average wind speed in September: 8.6mph
The windiest month (with the highest average wind speed) is May (12.6mph).
The calmest month (with the lowest average wind speed) is January (6.3mph).
Average humidity in September
Barstow, CA
- Average humidity in September: 27%
The months with the highest relative humidity are January and December (48%).
The month with the lowest relative humidity is August (23%).
Average rainfall in September
Barstow, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is December (0.55").
The driest month (with the least rainfall) is June (0").
Average rainfall days in September
Barstow, CA
- Average rainfall days in September: 1.9 days
The month with the highest number of rainy days is December (5.6 days).
The month with the least rainy days is June (0.2 days).
Average snowfall in September
Barstow, CA
- Average snowfall in September: 0"
The month with the highest snowfall is November (0.39").
The months with the least snowfall are February, March, April, May, June, July, August, September, October and December (0").
Average snowfall days in September
Barstow, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (0.4 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
Barstow, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 10h and 42min
The months with the most sunshine are June, July and August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 7h and 6min).
Average sunshine days in September
Barstow, CA
- Average sunshine days in September: 27.5 days
The month with the most sunshine days is June (29.8 days).
The month with the least sunshine days is February (22.8 days).
Average UV index in September
Barstow, CA
- Average UV index in September: 6
The month with the highest UV index is July (UV index 8).
The months with the lowest UV index are November and December (UV index 3).
Average cloud cover in September
Barstow, CA
- Average cloud cover in September: 5
The month with the most cloud cover is December (Cloud cover 19).
The months with the least cloud cover are June, August and September (Cloud cover 5).
Average visibility in September
Barstow, 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).





