Weather Highlights
Summer High: the July high is around 93 degrees
Winter Low: the January low is 43
Rain: averages 19 inches of rain a year
Snow: averages 0 inches of snow a year
BESTPLACES COMFORT INDEX
The annual BestPlaces Comfort Index for the Rancho Cucamonga area is 8.3 (10=best), which means it is more comfortable than most places in California.
8.3 / 10
A higher score indicates a more comfortable year-round climate. The US average for the comfort index is 7.8. Our index is based on the total number of days annually within the comfort range of 70-80 degrees, and we also applied a penalty for days of excessive humidity.
Average Monthly High and Low (°F)
| High | Low |
| January | 67° | 43° |
| February | 67° | 44° |
| March | 71° | 46° |
| April | 76° | 49° |
| May | 80° | 54° |
| June | 86° | 58° |
| July | 93° | 63° |
| August | 94° | 63° |
| September | 90° | 61° |
| October | 82° | 54° |
| November | 73° | 46° |
| December | 67° | 42° |
Hot, Freezing, Rainy, Snowy Days: Rancho Cucamonga
| Hot
Days | Freezing
Days | Rainy
Days | Snowy
Days |
| January | 0 | 1 | 6 | 0 |
| February | 0 | 0 | 6 | 0 |
| March | 1 | 0 | 6 | 0 |
| April | 2 | 0 | 3 | 0 |
| May | 5 | 0 | 2 | 0 |
| June | 11 | 0 | 1 | 0 |
| July | 21 | 0 | 0 | 0 |
| August | 23 | 0 | 1 | 0 |
| September | 16 | 0 | 1 | 0 |
| October | 7 | 0 | 3 | 0 |
| November | 1 | 0 | 3 | 0 |
| December | 0 | 1 | 5 | 0 |
YOU SHOULD KNOW
Many people confuse weather and climate but they are different. Weather is the conditions of the atmosphere over a short period of time, and climate is how the atmosphere is over long periods of time.
Weather is how the atmosphere is behaving and its effects upon life and human activities. Weather can change from minute-to-minute. Most people think of weather in terms of temperature, humidity, precipitation, cloudiness, brightness, visibility, wind, and atmospheric pressure.
Climate is the description of the long-term pattern of weather in a place. Climate can mean the average weather for a particular region and time period taken over 30 years. Climate is the average of weather over time.