September weather forecastRubidoux, CA
September
Weather in September
The first month of the autumn, September, is still a hot month in Rubidoux, California, with temperature in the range of an average low of 64°F (17.8°C) and an average high of 88.3°F (31.3°C).Temperature
Rubidoux marks the arrival of September with an average high-temperature of a still tropical 88.3°F (31.3°C), hardly different from August's 91.2°F (32.9°C). September nights experience a distinct temperature drop from the daily highs, with an average low-temperature of 64°F (17.8°C).Heat index
September's average heat index is calculated to be a tropical 89.6°F (32°C). Fatigue might occur with continuous exposure and activity, potentially causing heat cramps.Heat index readings emphasize conditions of light breezes and shaded spots. Direct sunlight exposure may result in a rise of the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', embodies the combination of air temperature and moisture content to illustrate perceived heat. Metabolic differences, pregnancy status, and the level of physical activity are additional factors influencing an individual's weather perception. Keep aware, the sun, when shining directly, can intensify the heat experience, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Children often fail to recognize the requirement to rest and rehydrate. Thirst, being a late symptom of dehydration, underlines the importance of maintaining hydration, especially during ongoing physical activities.
Humidity
In September, the average relative humidity is 45%.Rainfall
In September, the rain falls for 2.1 days. Throughout September, 0.08" (2mm) of precipitation is accumulated. In Rubidoux, during the entire year, the rain falls for 49 days and collects up to 7.32" (186mm) of precipitation.Snowfall
In Rubidoux, snow does not fall in January, March through December.Daylight
In September, the average length of the day is 12h and 22min.On the first day of the month, sunrise is at 6:23 am and sunset at 7:14 pm. On the last day of September, sunrise is at 6:44 am and sunset at 6:34 pm PDT.
Sunshine
In September, the average sunshine is 10.6h.UV index
In September, the average daily maximum UV index is 6. A UV Index of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for average individuals.Note: The maximum UV index of 6 during September translates into these guidelines:
Shield from overexposure. Defense against sun-related harm is required. Make an effort to avoid direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation, and note that objects like parasols or canopies might not offer full sun protection. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Rubidoux, CA
- Average high temperature in September: 88.3°F
The warmest month (with the highest average high temperature) is August (91.2°F).
The month with the lowest average high temperature is December (63.3°F).
- Average low temperature in September: 64°F
The month with the highest average low temperature is August (66.4°F).
The coldest month (with the lowest average low temperature) is December (45.9°F).
Average pressure in September
Rubidoux, CA
- Average pressure in September: 29.88"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed in September
Rubidoux, CA
- Average wind speed in September: 4.4mph
The windiest month (with the highest average wind speed) is May (5.6mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).
Average humidity in September
Rubidoux, CA
- Average humidity in September: 45%
The month with the highest relative humidity is May (56%).
The month with the lowest relative humidity is August (43%).
Average rainfall in September
Rubidoux, CA
- Average rainfall in September: 0.08"
The wettest months (with the highest rainfall) are February and December (1.61").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Rubidoux, CA
- Average rainfall days in September: 2.1 days
The month with the highest number of rainy days is March (7.7 days).
The month with the least rainy days is June (1.1 days).
Average snowfall days in September
Rubidoux, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Rubidoux, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 10h and 36min
The months with the most sunshine are July and August (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 48min).
Average sunshine days in September
Rubidoux, CA
- Average sunshine days in September: 25.8 days
The month with the most sunshine days is June (27.9 days).
The month with the least sunshine days is February (21.6 days).
Average UV index in September
Rubidoux, CA
- Average UV index in September: 6
The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Rubidoux, CA
- Average cloud cover in September: 7
The months with the most cloud cover are February and March (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
Rubidoux, 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).





