Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
January | 24°F | 41°F | 31°F | 4.1" |
February | 26°F | 44°F | 34°F | 5.6" |
March | 34°F | 55°F | 43°F | 6.4" |
April | 44°F | 68°F | 55°F | 6.1" |
May | 55°F | 76°F | 64°F | 9.2" |
June | 63°F | 84°F | 72°F | 6.0" |
July | 66°F | 87°F | 76°F | 5.5" |
August | 64°F | 85°F | 73°F | 7.7" |
September | 58°F | 79°F | 67°F | 7.6" |
October | 46°F | 67°F | 55°F | 9.4" |
November | 36°F | 55°F | 44°F | 5.4" |
December | 30°F | 46°F | 37°F | 6.8" |
Index | Potomac | Maryland | National |
Air quality index | 47 | 43 | 42 |
Pollution index | 14,693,900 | 5,342,367 | 2,726,193 |
Measurement | Total |
Days measured | 365 |
Days with good air quality | 209 |
Days with moderate air quality | 145 |
Days w/ poor A.Q. for sensitive groups | 10 |
Days with unhealthy air quality | 1 |
Pollutant | Total |
Arsenic | 0.190% |
Benzene | 0.210% |
Carbon Tetrachloride | 0.060% |
Lead | 0.060% |
Mercury | 0.010% |
City | Population | Air Quality Index | National Avg. |
Dulles Town Center, VA | 5,362 | 47 | 6.0% |
Calverton, MD | 17,034 | 47 | 6.0% |
Derwood, MD | 1,644 | 47 | 6.0% |
Montgomery Village, MD | 34,413 | 47 | 6.0% |
Washington Grove, MD | 710 | 47 | 6.0% |
Potomac, MD | 46,256 | 47 | 6.0% |
City | Population | Air Quality Index | National Avg. |
Everett, MA | 46,275 | 43 | 14.0% |
Mission, BC | 46,224 | n/a | |
West Vancouver, BC | 46,220 | n/a | |
Littleton, CO | 46,208 | 58 | 16.0% |
Titusville, FL | 46,307 | 37 | 26.0% |
Potomac, MD | 46,256 | 47 | 6.0% |