| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 25°F | 46°F | 34°F | 3.1" |
| February | 25°F | 47°F | 36°F | 2.7" |
| March | 33°F | 58°F | 45°F | 3.6" |
| April | 43°F | 70°F | 56°F | 3.8" |
| May | 52°F | 77°F | 65°F | 4.1" |
| June | 62°F | 86°F | 74°F | 4.7" |
| July | 67°F | 90°F | 78°F | 4.5" |
| August | 65°F | 88°F | 76°F | 4.7" |
| September | 58°F | 82°F | 70°F | 4.3" |
| October | 47°F | 70°F | 58°F | 5.7" |
| November | 36°F | 59°F | 47°F | 2.8" |
| December | 30°F | 50°F | 39°F | 4.3" |
| Index | Columbia | Maryland | National |
| Air quality index | 46 | 43 | 42 |
| Pollution index | 14,735,000 | 5,342,367 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 223 |
| Days with moderate air quality | 129 |
| Days w/ poor A.Q. for sensitive groups | 13 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.220% |
| Benzene | 0.090% |
| Carbon Tetrachloride | 0.030% |
| Lead | 0.110% |
| Mercury | 0.270% |
| City | Population | Air Quality Index | National Avg. |
| Ellicott City, MD | 73,272 | 46 | 8.0% |
| Randallstown, MD | 35,661 | 46 | 8.0% |
| Garrison, MD | 8,794 | 46 | 8.0% |
| Towson, MD | 57,542 | 46 | 8.0% |
| Fort Meade, MD | 11,340 | 46 | 8.0% |
| Columbia, MD | 105,412 | 46 | 8.0% |
| City | Population | Air Quality Index | National Avg. |
| League City, TX | 105,410 | 52 | 4.0% |
| Chatham-Kent, ON | 105,414 | n/a | |
| Santa Maria, CA | 105,528 | 46 | 8.0% |
| Davie, FL | 105,594 | 41 | 18.0% |
| Brantford, ON | 105,103 | n/a | |
| Columbia, MD | 105,412 | 46 | 8.0% |
Here are the best places to live in Maryland
Check out the 10 safest cities in Maryland
These are the 10 cheapest cities in Maryland
These are the largest cities in Maryland