| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 44°F | 70°F | 56°F | 1.6" |
| February | 45°F | 72°F | 57°F | 1.2" |
| March | 47°F | 75°F | 60°F | 0.7" |
| April | 50°F | 78°F | 63°F | 0.5" |
| May | 55°F | 82°F | 66°F | 0.2" |
| June | 59°F | 89°F | 72°F | 0.0" |
| July | 65°F | 94°F | 77°F | 0.2" |
| August | 65°F | 95°F | 78°F | 0.1" |
| September | 63°F | 94°F | 76°F | 0.2" |
| October | 56°F | 85°F | 69°F | 0.2" |
| November | 49°F | 77°F | 62°F | 0.5" |
| December | 44°F | 69°F | 55°F | 1.9" |
| Index | Airport | Riverside | California |
| Air quality index | 89 | 89 | 55 |
| Pollution index | 22,790,900 | 22,790,900 | 10,473,190 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 42 |
| Days with moderate air quality | 178 |
| Days w/ poor A.Q. for sensitive groups | 79 |
| Days with unhealthy air quality | 58 |
| Pollutant | Total |
| Arsenic | 0.060% |
| Benzene | 0.190% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.220% |
| Mercury | 0.230% |
| City | Population | Air Quality Index | National Avg. |
| Highgrove, CA | 6,201 | 89 | 78.0% |
| Chino, CA | 89,170 | 89 | 78.0% |
| Montclair, CA | 40,041 | 89 | 78.0% |
| Upland, CA | 77,348 | 89 | 78.0% |
| El Sobrante, CA | 14,779 | 89 | 78.0% |
| Riverside, CA | 327,569 | 89 | 78.0% |
| City | Population | Air Quality Index | National Avg. |
| Corpus Christi, TX | 326,332 | 42 | 16.0% |
| Santa Ana, CA | 332,610 | 89 | 78.0% |
| Lexington-Fayette, KY | 322,200 | 42 | 16.0% |
| Vaughan, ON | 321,974 | n/a | |
| Stockton, CA | 311,103 | 45 | 10.0% |
| Riverside, CA | 327,569 | 89 | 78.0% |
Here are the best places to live in California
Most Dangerous Cities In The US
Check out the 10 most dangerous cities in California
See the best places to live in Riverside