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 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
The arrival of September sees an average high-temperature of a still tropical 88.3°F (31.3°C), hardly diverging from August's 91.8°F (33.2°C). During September, Rancho Cucamonga notes a substantial drop from the daytime peak to an average minimum temperature of 63.7°F (17.6°C).Heat index
In September, the average heat index is appraised at a tropical 89.6°F (32°C). Enduring exposure and ongoing activity could cause a sense of fatigue and subsequent heat cramps.Understand that the heat index values take into account shaded locations and mild winds. Direct sunlight can potentially boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is derived by integrating air temperature with the existing relative humidity to express the perceived warmth. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. Take note that direct exposure to the sun can increase the felt temperature, possibly adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values hold particular significance for children. Young children typically face greater hazards than adults because they do not sweat as much. Their larger skin surface in comparison to their little bodies and the high heat production from their active nature compounds their vulnerability.
Humidity
In September, the average relative humidity is 43%.Rainfall
In Rancho Cucamonga, California, in September, during 1.8 rainfall days, 0.08" (2mm) of precipitation is typically accumulated. Throughout the year, there are 42.3 rainfall days, and 4.53" (115mm) of precipitation is accumulated.Snowfall
January, March through December are months without snowfall.Daylight
In Rancho Cucamonga, the average length of the day in September is 12h and 22min.On the first day of September, sunrise is at 6:24 am and sunset at 7:15 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 6:35 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 unprotected exposure to Sun's UV rays for ordinary individuals.Note: The maximum daily UV index, 6 in September, converts into the following recommendations:
Escape overexposure. People with light skin may incur burns in fewer than 20 minutes. Stay out of direct sunlight and seek shade between 10 a.m. and 4 p.m., when UV radiation is strongest, but remember that shade devices may not offer full sun protection. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot does it get in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September in Rancho Cucamonga?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Rancho Cucamonga, CA
- Average high temperature in September: 88.3°F
The warmest month (with the highest average high temperature) is August (91.8°F).
The month with the lowest average high temperature is December (61.7°F).
- Average low temperature in September: 63.7°F
The month with the highest average low temperature is August (66.6°F).
The coldest months (with the lowest average low temperature) are February and December (45.3°F).
Average pressure in September
Rancho Cucamonga, 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
Rancho Cucamonga, CA
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is May (5.9mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).
Average humidity in September
Rancho Cucamonga, CA
- Average humidity in September: 43%
The months with the highest relative humidity are February, March and May (53%).
The month with the lowest relative humidity is August (41%).
Average rainfall in September
Rancho Cucamonga, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is February (0.98").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Rancho Cucamonga, CA
- Average rainfall days in September: 1.8 days
The month with the highest number of rainy days is March (6.3 days).
The month with the least rainy days is June (0.9 days).
Average snowfall days in September
Rancho Cucamonga, 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
Rancho Cucamonga, CA
- Average daylight in September: 12h and 2min
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 4min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 54min).
Average sunshine days in September
Rancho Cucamonga, CA
- Average sunshine days in September: 26 days
The month with the most sunshine days is June (28.3 days).
The month with the least sunshine days is February (22.8 days).
Average UV index in September
Rancho Cucamonga, 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
Rancho Cucamonga, CA
- Average cloud cover in September: 6
The months with the most cloud cover are February and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
Rancho Cucamonga, 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).
Rancho Cucamonga, California, USA
Weather forecast for your location
2. Allow the app to use your location