| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 28°F | 46°F | 37°F | 2.9" |
| February | 28°F | 48°F | 38°F | 2.3" |
| March | 36°F | 57°F | 46°F | 3.1" |
| April | 45°F | 68°F | 56°F | 3.5" |
| May | 54°F | 77°F | 65°F | 3.1" |
| June | 64°F | 85°F | 74°F | 5.6" |
| July | 69°F | 89°F | 78°F | 4.5" |
| August | 67°F | 87°F | 76°F | 4.8" |
| September | 61°F | 81°F | 70°F | 4.7" |
| October | 50°F | 71°F | 60°F | 4.4" |
| November | 39°F | 60°F | 49°F | 2.9" |
| December | 33°F | 52°F | 42°F | 3.6" |
| Index | Long Neck | Delaware | National |
| Air quality index | 36 | 41 | 42 |
| Pollution index | 7,219,540 | 7,274,307 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 303 |
| Days with moderate air quality | 61 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality |
| Pollutant | Total |
| Arsenic | 0.060% |
| Benzene | 0.070% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.030% |
| Mercury | 0.110% |
| City | Population | Air Quality Index | National Avg. |
| Dagsboro, DE | 1,064 | 36 | 28.0% |
| Georgetown, DE | 7,641 | 36 | 28.0% |
| Millville, DE | 1,515 | 36 | 28.0% |
| South Bethany, DE | 569 | 36 | 28.0% |
| Fenwick Island, DE | 454 | 36 | 28.0% |
| Long Neck, DE | 2,953 | 36 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Arcola, IL | 2,953 | 42 | 16.0% |
| Buckeye Lake, OH | 2,953 | 46 | 8.0% |
| Zellwood, FL | 2,952 | 37 | 26.0% |
| Wilton, IA | 2,952 | 32 | 36.0% |
| Lake City, PA | 2,954 | 36 | 28.0% |
| Long Neck, DE | 2,953 | 36 | 28.0% |