Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
January | 16°F | 37°F | 26°F | 0.8" |
February | 18°F | 40°F | 28°F | 1.1" |
March | 27°F | 52°F | 39°F | 0.8" |
April | 33°F | 60°F | 46°F | 2.6" |
May | 38°F | 64°F | 51°F | 3.6" |
June | 50°F | 78°F | 65°F | 4.5" |
July | 55°F | 86°F | 71°F | 4.0" |
August | 53°F | 84°F | 69°F | 1.6" |
September | 46°F | 73°F | 60°F | 3.4" |
October | 37°F | 62°F | 49°F | 3.5" |
November | 24°F | 47°F | 35°F | 1.6" |
December | 14°F | 34°F | 24°F | 1.1" |
Index | Roy | Montana | National |
Air quality index | 21 | 34 | 42 |
Pollution index | 263,666 | 834,473 | 2,726,193 |
Measurement | Total |
Days measured | 362 |
Days with good air quality | 357 |
Days with moderate air quality | 4 |
Days w/ poor A.Q. for sensitive groups | 0 |
Days with unhealthy air quality | 1 |
Pollutant | Total |
Arsenic | 0.000% |
Benzene | 0.005% |
Carbon Tetrachloride | 0.001% |
Lead | 0.010% |
Mercury | 0.000% |
City | Population | Air Quality Index | National Avg. |
Roy, MT | 120 | 21 | 58.0% |
City | Population | Air Quality Index | National Avg. |
Haleburg, AL | 120 | 35 | 30.0% |
Haynes, AR | 120 | 45 | 10.0% |
Pike, CA | 120 | 44 | 12.0% |
Nunez, GA | 120 | 47 | 6.0% |
Makaha Valley, HI | 120 | 30 | 40.0% |
Roy, MT | 120 | 21 | 58.0% |