| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 46°F | 72°F | 57°F | 2.3" |
| February | 48°F | 72°F | 58°F | 1.7" |
| March | 51°F | 75°F | 61°F | 1.0" |
| April | 54°F | 76°F | 64°F | 0.5" |
| May | 58°F | 78°F | 66°F | 0.3" |
| June | 62°F | 81°F | 70°F | 0.0" |
| July | 66°F | 86°F | 74°F | 0.1" |
| August | 66°F | 88°F | 75°F | 0.0" |
| September | 65°F | 88°F | 74°F | 0.2" |
| October | 59°F | 83°F | 69°F | 0.4" |
| November | 52°F | 77°F | 63°F | 0.6" |
| December | 45°F | 70°F | 56°F | 2.5" |
| Index | Norwalk | California | National |
| Air quality index | 72 | 55 | 50 |
| Pollution index | 139,490,000 | 18,106,726 | 5,066,862 |
| 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, State | Population | Air Quality Index | National Avg. |
| Compton, CA | 97,740 | 72 | 44% |
| Lomita, CA | 20,652 | 72 | 44% |
| Paramount, CA | 54,941 | 72 | 44% |
| Vernon, CA | 101 | 72 | 44% |
| Inglewood, CA | 111,012 | 72 | 44% |
| Norwalk, CA | 106,360 | 72 | 44% |
| City, State | Population | Air Quality Index | National Avg. |
| Pearland, TX | 106,238 | 52 | 4% |
| Palm Bay, FL | 106,573 | 36 | 28% |
| Everett, WA | 106,580 | 45 | 10% |
| Highlands Ranch, CO | 106,596 | 58 | 16% |
| North Charleston, SC | 106,113 | 38 | 24% |
| Norwalk, CA | 106,360 | 72 | 44% |
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