| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 36°F | 57°F | 45°F | 2.0" |
| February | 39°F | 61°F | 48°F | 1.5" |
| March | 47°F | 70°F | 57°F | 3.0" |
| April | 55°F | 77°F | 64°F | 3.5" |
| May | 62°F | 82°F | 71°F | 4.1" |
| June | 71°F | 91°F | 80°F | 3.1" |
| July | 74°F | 94°F | 84°F | 2.8" |
| August | 74°F | 95°F | 84°F | 2.2" |
| September | 67°F | 87°F | 76°F | 2.3" |
| October | 56°F | 78°F | 66°F | 2.9" |
| November | 47°F | 67°F | 56°F | 2.0" |
| December | 38°F | 57°F | 46°F | 1.7" |
| Index | Decatur | Texas | National |
| Air quality index | 33 | 52 | 42 |
| Pollution index | 1,399,310 | 2,009,300 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 329 |
| Days with moderate air quality | 33 |
| Days w/ poor A.Q. for sensitive groups | 3 |
| Days with unhealthy air quality |
| Pollutant | Total |
| Arsenic | 0.003% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.010% |
| Mercury | 0.002% |
| City | Population | Air Quality Index | National Avg. |
| Alvord, TX | 1,104 | 26 | 48.0% |
| Chico, TX | 1,166 | 26 | 48.0% |
| Boyd, TX | 1,375 | 33 | 34.0% |
| Bridgeport, TX | 6,498 | 33 | 34.0% |
| Aurora, TX | 1,497 | 33 | 34.0% |
| Decatur, TX | 6,976 | 33 | 34.0% |
| City | Population | Air Quality Index | National Avg. |
| Benton, IL | 6,977 | 43 | 14.0% |
| Milltown, NJ | 6,973 | 41 | 18.0% |
| Oak Ridge, NC | 6,979 | 43 | 14.0% |
| Chatsworth, ON | 6,972 | n/a | |
| Old Greenwich, CT | 6,980 | 43 | 14.0% |
| Decatur, TX | 6,976 | 33 | 34.0% |
Here are the best places to live in Texas
Check out the 10 safest cities in Texas
Safest Cities In The US
Check out the 10 most dangerous cities in Texas