Air pollution statistics for Montgomery Co, Texas
3. Select a year
| Year | Percentage days with good air | Percentage days with moderate air | Percentage days with unhealthy air for sensitive groups | Percentage days with unhealthy air |
| 1999 | 80.68% | 14.77% | 3.41% | 1.14% |
| 2000 | 73.77% | 21.31% | 4.64% | 0.27% |
| 2001 | 77.68% | 19.88% | 2.45% | 0.00% |
| 2002 | 82.55% | 16.62% | 0.55% | 0.28% |
| 2003 | 76.99% | 21.10% | 1.37% | 0.55% |
| 2004 | 86.34% | 13.11% | 0.55% | 0.00% |
| 2005 | 75.00% | 24.44% | 0.28% | 0.28% |
| 2006 | 76.44% | 21.64% | 1.64% | 0.27% |
| 2007 | 82.08% | 17.92% | 0.00% | 0.00% |