| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 46°F | 71°F | 58°F | 1.1" |
| February | 49°F | 76°F | 62°F | 0.5" |
| March | 54°F | 83°F | 69°F | 0.2" |
| April | 58°F | 88°F | 73°F | 0.1" |
| May | 65°F | 96°F | 80°F | 0.0" |
| June | 73°F | 106°F | 90°F | 0.0" |
| July | 80°F | 109°F | 94°F | 0.3" |
| August | 79°F | 108°F | 94°F | 0.3" |
| September | 74°F | 103°F | 88°F | 0.3" |
| October | 63°F | 91°F | 77°F | 0.1" |
| November | 54°F | 80°F | 67°F | 0.1" |
| December | 45°F | 70°F | 57°F | 1.0" |
| Index | Mountain Center | California | National |
| Air quality index | 85 | 55 | 50 |
| Pollution index | 22,790,900 | 18,106,726 | 5,066,862 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 24 |
| Days with moderate air quality | 211 |
| Days w/ poor A.Q. for sensitive groups | 102 |
| Days with unhealthy air quality | 25 |
| Pollutant | Total |
| Arsenic | 0.060% |
| Benzene | 0.190% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.220% |
| Mercury | 0.230% |
| City, State | Population | Air Quality Index | National Avg. |
| East Hemet, CA | 18,764 | 85 | 70% |
| Palm Springs, CA | 46,714 | 85 | 70% |
| Anza, CA | 2,507 | 85 | 70% |
| Garnet, CA | 6,297 | 85 | 70% |
| San Jacinto, CA | 46,375 | 85 | 70% |
| Mountain Center, CA | 80 | 85 | 70% |
| City, State | Population | Air Quality Index | National Avg. |
| Wildrose, ND | 80 | 41 | 18% |
| Weingarten, MO | 80 | 60 | 20% |
| Middleburg, NC | 80 | 34 | 32% |
| Clyde, MO | 80 | 45 | 10% |
| Ames, NE | 80 | 48 | 4% |
| Mountain Center, CA | 80 | 85 | 70% |