| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 27°F | 43°F | 34°F | 3.3" |
| February | 26°F | 43°F | 34°F | 2.5" |
| March | 34°F | 54°F | 43°F | 3.7" |
| April | 44°F | 66°F | 54°F | 4.9" |
| May | 52°F | 74°F | 63°F | 3.2" |
| June | 64°F | 83°F | 73°F | 5.0" |
| July | 68°F | 87°F | 77°F | 5.6" |
| August | 67°F | 86°F | 76°F | 3.7" |
| September | 59°F | 79°F | 69°F | 4.1" |
| October | 48°F | 67°F | 57°F | 6.1" |
| November | 40°F | 57°F | 48°F | 3.3" |
| December | 30°F | 46°F | 38°F | 5.3" |
| Index | Arden | Delaware | National |
| Air quality index | 51 | 41 | 42 |
| Pollution index | 2,169,600 | 7,274,307 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 180 |
| Days with moderate air quality | 169 |
| Days w/ poor A.Q. for sensitive groups | 16 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.030% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.004% |
| City | Population | Air Quality Index | National Avg. |
| Pennsville, NJ | 11,968 | 40 | 20.0% |
| Woodstown, NJ | 3,445 | 40 | 20.0% |
| Downingtown, PA | 8,012 | 42 | 16.0% |
| Brookside, DE | 13,741 | 42 | 16.0% |
| Glasgow, DE | 15,399 | 42 | 16.0% |
| Arden, DE | 535 | 51 | 2.0% |
| City | Population | Air Quality Index | National Avg. |
| Nuiqsut, AK | 535 | 38 | 24.0% |
| Crawfordville, GA | 535 | 44 | 12.0% |
| Ashton, IA | 535 | 36 | 28.0% |
| Creston, IL | 535 | 42 | 16.0% |
| Riverwood, KY | 535 | 49 | 2.0% |
| Arden, DE | 535 | 51 | 2.0% |
Here are the best places to live in Delaware
These are the 10 cheapest cities in Delaware
See the best places to live in Arden
Most Dangerous States In The US