| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 31°F | 62°F | 45°F | 0.8" |
| February | 35°F | 67°F | 51°F | 0.5" |
| March | 42°F | 74°F | 58°F | 0.2" |
| April | 47°F | 80°F | 64°F | 0.0" |
| May | 55°F | 89°F | 73°F | 0.0" |
| June | 64°F | 100°F | 84°F | 0.0" |
| July | 71°F | 106°F | 90°F | 0.0" |
| August | 68°F | 104°F | 87°F | 0.1" |
| September | 60°F | 96°F | 79°F | 0.2" |
| October | 49°F | 83°F | 66°F | 0.1" |
| November | 38°F | 71°F | 54°F | 0.2" |
| December | 30°F | 59°F | 44°F | 0.5" |
| Index | Johannesburg | California | National |
| Air quality index | 67 | 55 | 42 |
| Pollution index | 21,095,500 | 10,473,190 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 119 |
| Days with moderate air quality | 151 |
| Days w/ poor A.Q. for sensitive groups | 87 |
| Days with unhealthy air quality | 6 |
| Pollutant | Total |
| Arsenic | 1.700% |
| Benzene | 0.350% |
| Carbon Tetrachloride | 0.004% |
| Lead | 0.580% |
| Mercury | 1.550% |
| City | Population | Air Quality Index | National Avg. |
| Randsburg, CA | 99 | 67 | 34.0% |
| Johannesburg, CA | 48 | 67 | 34.0% |
| City | Population | Air Quality Index | National Avg. |
| Chenega, AK | 48 | 31 | 38.0% |
| Morrison Bluff, AR | 48 | 36 | 28.0% |
| Robinson Mill, CA | 48 | 44 | 12.0% |
| Cobbtown, FL | 48 | 41 | 18.0% |
| Aredale, IA | 48 | 15 | 70.0% |
| Johannesburg, CA | 48 | 67 | 34.0% |
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