Technology Transfer Network / NAAQS
Ozone Implementation
Ozone Monitoring Season
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
40 CFR 58 Appendix D as of July 1, 2004
Since ozone levels decrease significantly in the colder parts of the
year in many areas, ozone is required to be monitored at NAMS and SLAMS
monitoring sites only during the ``ozone season'' as designated in the
AIRS files on a State by State basis and described below:
Ozone Monitoring Season By State
------------------------------------------------------------------------
State Begin month End month
------------------------------------------------------------------------
Alabama......................... March............. October.
Alaska.......................... April............. October.
Arizona......................... January........... December.
Arkansas........................ March............. November.
California...................... January........... December.
Colorado........................ March............. September.
Connecticut..................... April............. September.
Delaware........................ April............. October.
District of Columbia............ April............. October.
Florida......................... March............. October.
Georgia......................... March............. October.
Hawaii.......................... January........... December.
Idaho........................... April............. October.
Illinois........................ April............. October.
Indiana......................... April............. September.
Iowa............................ April............. October.
Kansas.......................... April............. October.
Kentucky........................ March............. October.
Louisiana AQCRs 019, 022........ March............. October.
Louisiana AQCR 106.............. January........... December.
Maine........................... April............. September.
Maryland........................ April............. October.
Massachusetts................... April............. September.
Michigan........................ April............. September.
Minnesota....................... April............. October.
Mississippi..................... March............. October.
Missouri........................ April............. October.
Montana......................... June.............. September.
Nebraska........................ April............. October.
Nevada.......................... January........... December.
New Hampshire................... April............. September.
New Jersey...................... April............. October.
New Mexico...................... January........... December.
New York........................ April............. October.
North Carolina.................. April............. October.
North Dakota.................... May............... September.
Ohio............................ April............. October.
Oklahoma........................ March............. November.
Oregon.......................... May............... September.
Pennsylvania.................... April............. October.
Puerto Rico..................... January........... December.
Rhode Island.................... April............. September.
South Carolina.................. April............. October.
South Dakota.................... June.............. September.
Tennessee....................... March............. October.
Texas AQCR 4,5,7,10,11.......... January........... December
Texas AQCR 1, 2, 3, 6, 8, 9, 12. March............. October
Utah............................ May............... September.
Vermont......................... April............. September.
Virginia........................ April............. October.
Washington...................... May............... September.
West Virginia................... April............. October.
Wisconsin....................... April 15.......... October 15.
Wyoming......................... April............. October.
American Samoa.................. January........... December.
Guam............................ January........... December.
Virgin Islands.................. January........... December.
------------------------------------------------------------------------
[44 FR 27571, May 10, 1979; 44 FR 72592, Dec. 14, 1979, as amended at 46
FR 44168, Sept. 3, 1981; 51 FR 9597, Mar. 19, 1986; 52 FR 24742--23744,
July 1, 1987; 52 FR 27286, July 20, 1987; 54 FR 15183, Apr. 17, 1989; 56
FR 64483, Dec. 10, 1991; 57 FR 44496, Sept. 28, 1992; 58 FR 8469, Feb.
12, 1993; 59 FR 41628, Aug. 12, 1994; 60 FR 11909, Mar. 3, 1995; 60 FR
52323, Oct. 6, 1995; 62 FR 6729, Feb. 13, 1997; 62 FR 18525, Apr. 16,
1997; 62 FR 38844, July 18, 1997; 63 FR 7715, Feb. 17, 1998; 64 FR 3028,
Jan. 20, 1999; 67 FR 57332, Sept. 10, 2002]
CHANGES TO OZONE SEASON:
September 10, 2002 (Effective November 12, 2002) Louisiana AQCRs
019 and 022 changed to March - October
January 20, 1999 (Effective March 22, 1999) Washington and Oregon changed
to May 1 - September 30
April 16, 1997 (Effective June 16, 1997) Connecticut, Maine, Massachusetts,
New Hampshire, Rhode Island, and Vermont changed to April 1-September
30
February 13, 1997 (Effective March 17, 1997) Alabama, Georgia and Mississippi
changed to April 1 -October 31
March 3, 1995 Wisconsin changed to April 15 - October 15
On September 28, 1992 (Effective Nov 27, 1992) Michigan was changed to
"April 1 to September 30" beginning in 1992
December 10, 1991 (Effective November 26, 1991) Indiana was changed to
"April 1 to September 30" beginning 1991
April 17, 1989 (Effective Jan 17, 1989) Texas was changed to March - October for AQCR 1,2,3,6,8,9,12 (applies to 1998 ozone season and future monitoring) (AQCR 4,5,7,10,11 remain at Jan-Dec)
The Federal Register on March 19, 1986 listed the ozone seasons for all states.
THE FOLLOWING DO NOT RELATE TO THE OZONE SEASON:
Feb 17, 1998 Corrections to July 18, 1997
July 18, 1997 - PM sub 2.5
October 6, 1995 -Siting criteria (does not relate to changing ozone season)
July 18, 1997
Aug 12, 1994 AIRS data
Feb 12, 1993 revises the ambient air quality surveillance regulations
52 FR 27286, July 20, 1987 PM Correction Notice
52 FR 24742--23744, July 1, 1987 - PM Notice
FR 44168, Sept. 3, 1981 - Lead
44 FR 72592, Dec. 14, 1979 - Corrections to previous notices
44 FR 27571, May 10, 1979 - Part 58 Ambient Air Quality Surveillance