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 | Southeast | Helena | Montana |
Air quality index | 40 | 40 | 34 |
Pollution index | 1,148,190 | 1,148,190 | 685,925 |
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, State | Population | Air Quality Index | National Avg. |
Montana City, MT | 2,878 | 40 | 20% |
Helena Valley Northwest, MT | 3,967 | 40 | 20% |
Marysville, MT | 92 | 40 | 20% |
Spokane Creek, MT | 317 | 40 | 20% |
Helena Valley Southeast, MT | 7,543 | 40 | 20% |
Helena, MT | 30,102 | 40 | 20% |
City, State | Population | Air Quality Index | National Avg. |
Myrtle Beach, SC | 30,106 | 14 | 72% |
Orcutt, CA | 30,109 | 46 | 8% |
Burlingame, CA | 30,118 | 43 | 14% |
Holly Springs, NC | 30,126 | 46 | 8% |
Lawrenceville, GA | 30,127 | 37 | 26% |
Helena, MT | 30,102 | 40 | 20% |