Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
January | 13°F | 35°F | 24°F | 0.6" |
February | 18°F | 41°F | 28°F | 0.7" |
March | 25°F | 52°F | 38°F | 0.5" |
April | 31°F | 60°F | 44°F | 0.9" |
May | 39°F | 69°F | 53°F | 1.8" |
June | 47°F | 79°F | 63°F | 2.0" |
July | 55°F | 91°F | 73°F | 0.7" |
August | 52°F | 88°F | 69°F | 1.1" |
September | 44°F | 77°F | 59°F | 1.1" |
October | 34°F | 62°F | 46°F | 0.8" |
November | 23°F | 47°F | 34°F | 0.8" |
December | 12°F | 33°F | 22°F | 0.8" |
Index | Helena | Montana | National |
Air quality index | 40 | 34 | 42 |
Pollution index | 1,148,190 | 834,473 | 2,726,193 |
Measurement | Total |
Days measured | 365 |
Days with good air quality | 288 |
Days with moderate air quality | 75 |
Days w/ poor A.Q. for sensitive groups | 2 |
Days with unhealthy air quality | 0 |
Pollutant | Total |
Arsenic | 0.000% |
Benzene | 0.020% |
Carbon Tetrachloride | 0.002% |
Lead | 0.010% |
Mercury | 0.000% |
City | Population | Air Quality Index | National Avg. |
Jefferson City, MT | 596 | 40 | 20.0% |
Helena Valley Northeast, MT | 3,519 | 40 | 20.0% |
Helena West Side, MT | 1,656 | 40 | 20.0% |
Montana City, MT | 2,821 | 40 | 20.0% |
Helena Valley Northwest, MT | 4,256 | 40 | 20.0% |
Helena, MT | 32,655 | 40 | 20.0% |
City | Population | Air Quality Index | National Avg. |
Orangeville, ON | 32,668 | n/a | |
Matthews, NC | 32,682 | 49 | 2.0% |
Uniondale, NY | 32,621 | 51 | 2.0% |
St. Charles, IL | 32,612 | 55 | 10.0% |
Florence, KY | 32,721 | 54 | 8.0% |
Helena, MT | 32,655 | 40 | 20.0% |