| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 45°F | 62°F | 52°F | 19.1" |
| February | 46°F | 65°F | 54°F | 5.8" |
| March | 47°F | 69°F | 56°F | 3.2" |
| April | 47°F | 73°F | 58°F | 3.0" |
| May | 53°F | 79°F | 64°F | 0.6" |
| June | 59°F | 87°F | 71°F | 0.0" |
| July | 65°F | 96°F | 79°F | 0.0" |
| August | 63°F | 94°F | 76°F | 0.0" |
| September | 61°F | 90°F | 74°F | 28.1" |
| October | 57°F | 81°F | 67°F | 5.9" |
| November | 53°F | 74°F | 61°F | 1.3" |
| December | 44°F | 63°F | 52°F | 4.0" |
| Index | Stevenson Ranch | California | National |
| Air quality index | 72 | 55 | 42 |
| Pollution index | 139,490,000 | 10,473,190 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 66 |
| Days with moderate air quality | 208 |
| Days w/ poor A.Q. for sensitive groups | 62 |
| Days with unhealthy air quality | 28 |
| Pollutant | Total |
| Arsenic | 0.200% |
| Benzene | 0.950% |
| Carbon Tetrachloride | 0.080% |
| Lead | 1.320% |
| Mercury | 0.440% |
| City | Population | Air Quality Index | National Avg. |
| Thousand Oaks, CA | 131,108 | 46 | 8.0% |
| Piru, CA | 2,198 | 46 | 8.0% |
| Bell Canyon, CA | 2,062 | 72 | 44.0% |
| Santa Susana, CA | 953 | 72 | 44.0% |
| Val Verde, CA | 3,328 | 72 | 44.0% |
| Stevenson Ranch, CA | 19,485 | 72 | 44.0% |
| City | Population | Air Quality Index | National Avg. |
| Salmon Arm, BC | 19,494 | n/a | |
| Seabrook, MD | 19,461 | 47 | 6.0% |
| Liberal, KS | 19,510 | 15 | 70.0% |
| Hawthorne, NJ | 19,459 | 51 | 2.0% |
| Highland, UT | 19,513 | 46 | 8.0% |
| Stevenson Ranch, CA | 19,485 | 72 | 44.0% |