| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 42°F | 66°F | 53°F | 3.3" |
| February | 44°F | 67°F | 54°F | 2.5" |
| March | 47°F | 71°F | 58°F | 1.8" |
| April | 57°F | 81°F | 68°F | 3.0" |
| May | 63°F | 86°F | 74°F | 4.4" |
| June | 70°F | 90°F | 79°F | 8.5" |
| July | 72°F | 91°F | 80°F | 4.8" |
| August | 73°F | 90°F | 80°F | 6.6" |
| September | 70°F | 87°F | 77°F | 4.3" |
| October | 61°F | 81°F | 70°F | 2.7" |
| November | 49°F | 73°F | 60°F | 0.7" |
| December | 46°F | 69°F | 56°F | 1.9" |
| Index | Glen St. Mary | Florida | National |
| Air quality index | 38 | 35 | 42 |
| Pollution index | 6,554,710 | 7,570,785 | 2,726,193 |
| Measurement | Total |
| Days measured | 363 |
| Days with good air quality | 294 |
| Days with moderate air quality | 69 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.020% |
| Benzene | 0.040% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.070% |
| Mercury | 0.010% |
| City | Population | Air Quality Index | National Avg. |
| Raiford, FL | 229 | 38 | 24.0% |
| Macclenny, FL | 6,958 | 43 | 14.0% |
| Baldwin, FL | 1,602 | 43 | 14.0% |
| Glen St. Mary, FL | 687 | 38 | 24.0% |
| City | Population | Air Quality Index | National Avg. |
| Kennard, IN | 687 | 28 | 44.0% |
| Loch Lloyd, MO | 687 | 47 | 6.0% |
| Culbertson, MT | 687 | 34 | 32.0% |
| Lakota, ND | 687 | 33 | 34.0% |
| Beach City, OH | 687 | 46 | 8.0% |
| Glen St. Mary, FL | 687 | 38 | 24.0% |