| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 16°F | 34°F | 25°F | 2.3" |
| February | 18°F | 36°F | 27°F | 2.3" |
| March | 29°F | 49°F | 39°F | 2.8" |
| April | 38°F | 63°F | 50°F | 3.9" |
| May | 48°F | 73°F | 60°F | 5.4" |
| June | 59°F | 83°F | 71°F | 4.5" |
| July | 64°F | 86°F | 75°F | 5.2" |
| August | 63°F | 84°F | 74°F | 4.4" |
| September | 56°F | 78°F | 66°F | 3.6" |
| October | 44°F | 65°F | 54°F | 3.4" |
| November | 32°F | 52°F | 42°F | 2.3" |
| December | 21°F | 38°F | 29°F | 2.9" |
| Index | Northlake | Illinois | National |
| Air quality index | 60 | 41 | 50 |
| Pollution index | 14,981,300 | 3,347,295 | 5,066,862 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 72 |
| Days with moderate air quality | 281 |
| Days w/ poor A.Q. for sensitive groups | 11 |
| Days with unhealthy air quality | 1 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.140% |
| Carbon Tetrachloride | 0.030% |
| Lead | 0.020% |
| Mercury | 0.010% |
| City, State | Population | Air Quality Index | National Avg. |
| Elk Grove Village, IL | 33,251 | 60 | 20% |
| Evergreen Park, IL | 19,849 | 60 | 20% |
| Glendale Heights, IL | 34,395 | 60 | 20% |
| Hanover Park, IL | 38,331 | 60 | 20% |
| Hinsdale, IL | 17,438 | 60 | 20% |
| Northlake, IL | 12,339 | 60 | 20% |
| City, State | Population | Air Quality Index | National Avg. |
| North Merrick, NY | 12,337 | 53 | 6% |
| Steamboat Springs, CO | 12,336 | 43 | 14% |
| Bayou Blue, LA | 12,333 | 34 | 32% |
| Panama City Beach, FL | 12,333 | 37 | 26% |
| Cleveland, MS | 12,346 | 37 | 26% |
| Northlake, IL | 12,339 | 60 | 20% |