| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 18°F | 33°F | 25°F | 1.1" |
| February | 19°F | 34°F | 26°F | 1.4" |
| March | 30°F | 48°F | 38°F | 1.8" |
| April | 39°F | 60°F | 49°F | 2.7" |
| May | 49°F | 71°F | 60°F | 3.6" |
| June | 60°F | 81°F | 69°F | 4.7" |
| July | 65°F | 85°F | 74°F | 4.0" |
| August | 64°F | 83°F | 73°F | 4.4" |
| September | 56°F | 76°F | 66°F | 2.7" |
| October | 45°F | 64°F | 54°F | 3.2" |
| November | 34°F | 50°F | 42°F | 1.7" |
| December | 23°F | 37°F | 30°F | 2.0" |
| Index | Barrington | Illinois | National |
| Air quality index | 55 | 41 | 42 |
| Pollution index | 543,516 | 3,148,694 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 121 |
| Days with moderate air quality | 227 |
| Days w/ poor A.Q. for sensitive groups | 16 |
| Days with unhealthy air quality | 1 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.004% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Third Lake, IL | 1,160 | 39 | 22.0% |
| Holiday Hills, IL | 653 | 39 | 22.0% |
| Oakwood Hills, IL | 2,543 | 39 | 22.0% |
| Green Oaks, IL | 3,882 | 39 | 22.0% |
| North Chicago, IL | 29,967 | 39 | 22.0% |
| Barrington, IL | 10,442 | 55 | 10.0% |
| City | Population | Air Quality Index | National Avg. |
| Bellefontaine Neighbors, MO | 10,441 | 54 | 8.0% |
| Budd Lake, NJ | 10,444 | 34 | 32.0% |
| Mount Sinai, NY | 10,446 | 43 | 14.0% |
| Elizabethtown-Kitley, ON | 10,437 | n/a | |
| Ponoka County, AB | 10,437 | n/a | |
| Barrington, IL | 10,442 | 55 | 10.0% |
Here are the best places to live in Illinois
See the best places to live in Barrington
Check out the 10 safest cities in Illinois
Check out the 10 most dangerous cities in Illinois