Weather Makes a Difference: 8-hour
Ozone Trends for 1997-2007
State and Local Information for EPA Region 5
Illinois
Indiana
Michigan
Minnesota
Ohio
Wisconsin
Composite trend for available sites in these states:
EPA Region 05 (selected sites)
80
n
Cl
^70
40
<
03
O
I20
o'
h
o-
Adjusted for Weather
Unadjusted for Weather
Š*
.O.
8^
1998
2000
2002
Year
2004
2006
U.S. Environmental Protection Agency
Office of Air and Radiation
Office of Air Quality Planning and Standards
April 2008
-------
Illinois
Ozone
In Chicago ozone adjusted for weather conditions declined 7 percent between 1997 and
2007. These improvements in ozone are in response to both state and regional reductions
in NOx and VOC emissions. The level of ozone improvement varies from site to site.
Trends for 1997-2007 for rural sites and urban areas with complete ozone and
meteorology data are presented below. Ozone season (May 1 - September 30) averages
of daily maximum 8-hour ozone were adjusted to remove the influence of year-to-year
variability in weather conditions. The dotted line shows the trend in observed values at
monitoring sites, while the solid line illustrates the underlying ozone trend after removing
the effects of weather. The solid line serves as a m ore accurate ozone trend for assessing
changes in emissions. Typical weather conditions are determined by averaging
conditions (e.g., temperature, humidity, etc.) for the time period presented. The
information provided is useful for reviewing the weather influence for a particular ozone
season. The solid line represents ozone levels anticipated under typical weather
conditions.
Seasonal Average 8-hour Ozone Trends
Chicago, IL 8-hr Ozone Trends
.Q
Q.
CL
80 -
0
c
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N
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0°
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o.
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20
Adjusted for Weather
Unadjusted for Weather
1998
2000
2002
Year
2004
2006
-------
Indiana
Ozone
On average, ozone adjusted for weather conditions declined 14 percent between 1997 and
2007. These improvements in ozone are in response to both state and regional reductions
in NOx and VOC emissions. The level of ozone improvement varies from site to site.
Trends for 1997-2007 for rural sites and urban areas with complete ozone and
meteorology data are presented below. Ozone season (May 1 - September 30) averages
of daily maximum 8-hour ozone were adjusted to remove the influence of year-to-year
variability in weather conditions. The dotted line shows the trend in observed values at
monitoring sites, while the solid line illustrates the underlying ozone trend after removing
the effects of weather. The solid line serves as a m ore accurate ozone trend for assessing
changes in emissions. Typical weather conditions are determined by averaging
conditions (e.g., temperature, humidity, etc.) for the time period presented. The
information provided is useful for reviewing the weather influence for a particular ozone
season. The solid line represents ozone levels anticipated under typical weather
conditions.
Seasonal Average 8-hour Ozone Trends
Vincennes, IN
.Q
CL
CL
d) 80
c
o
N
o
SI 60
O)
CO
L.
CD
- 40
CO
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ci.)
Adjusted for Weather
Unadjusted for Weather
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o-
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o,
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o
20
1998
2000
2002
Year
2004
2006
-------
Fort Wayne, IN 8-hr Ozone Trends
n
CL
CL
-------
Salamonie Reservoir, IN
J2
CL
CL
0 80
-------
Michigan
Ozone
On average, ozone adjusted for weather conditions declined 12 percent between 1997 and
2007. These improvements in ozone are in response to both state and regional reductions
in NOx and VOC emissions. The level of ozone improvement varies from site to site.
Trends for 1997-2007 for rural sites and urban areas with complete ozone and
meteorology data are presented below. Ozone season (May 1 - September 30) averages
of daily maximum 8-hour ozone were adjusted to remove the influence of year-to-year
variability in weather conditions. The dotted line shows the trend in observed values at
monitoring sites, while the solid line illustrates the underlying ozone trend after removing
the effects of weather. The solid line serves as a m ore accurate ozone trend for assessing
changes in emissions. Typical weather conditions are determined by averaging
conditions (e.g., temperature, humidity, etc.) for the time period presented. The
information provided is useful for reviewing the weather influence for a particular ozone
season. The solid line represents ozone levels anticipated under typical weather
conditions.
Seasonal Average 8-hour Ozone Trends
Ann Arbor, Ml
n
Ql
Cl
0 80
c
o
N
o
ci) 60
D)
CC
L.
(1)
5: 40
cc
c
o
CO
m
03 on
ICO zu
Adjusted for Weather
Unadjusted for Weather
O,
0
.Ģ
^2-
L-O
1998
2000
2002
Year
2004
2006
-------
Detroit, Ml 8-hr Ozone Trends
.Q
CL
CL
0 80
c
o
N
O
Ŗ60
CD
m
L.
CD
: 40
cs
c
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w
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o-
. . o
%
.
O.
V
Adjusted for Weather
Unadjusted for Weather
! I I
1998 2000 2002
i i
2004 2006
Year
Grand Rapids, Ml 8-hr Ozone Trends
Ŗ2
CL
CL
d) 80
c
o
N
O
S.60
O)
03
L.
-------
Unionville, Ml
CL
Q.
0 80
c
o
N
O
0 60
OS
(0
L.
(D
5 40 H
CO
Ŗ=
O
-------
Minnesota
Ozone
On average, ozone adjusted for weather conditions declined 11 percent between 1997 and
2007. These improvements in ozone are in response to both state and regional reductions
in NOx and VOC emissions. The level of ozone improvement varies from site to site.
Trends for 1997-2007 for rural sites and urban areas with complete ozone and
meteorology data are presented below. Ozone season (May 1 - September 30) averages
of daily maximum 8-hour ozone were adjusted to remove the influence of year-to-year
variability in weather conditions. The dotted line shows the trend in observed values at
monitoring sites, while the solid line illustrates the underlying ozone trend after removing
the effects of weather. The solid line serves as a m ore accurate ozone trend for assessing
changes in emissions. Typical weather conditions are determined by averaging
conditions (e.g., temperature, humidity, etc.) for the time period presented. The
information provided is useful for reviewing the weather influence for a particular ozone
season. The solid line represents ozone levels anticipated under typical weather
conditions.
Seasonal Average 8-hour Ozone Trends
Voyageurs NP, MN
JD
CL
Cl
-------
Minneapolis, MN 8-hr Ozone Trends
n
a.
Cl
0 80
c
o
N
O
a) 60
o>
CO
CD
5 40
fro
c
o
cf,)
CO
CD on
CO zu
o*'
8^.^r8^88
Adjusted for Weather
Unadjusted for Weather
1998
2000
2002
Year
2004
2006
-------
Ohio
Ozone
On average, ozone adjusted for weather conditions declined 15 percent between 1997 and
2007. These improvements in ozone are in response to both state and regional reductions
in NOx and VOC emissions. The level of ozone improvement varies from site to site.
Trends for 1997-2007 for rural sites and urban areas with complete ozone and
meteorology data are presented below. Ozone season (May 1 - September 30) averages
of daily maximum 8-hour ozone were adjusted to remove the influence of year-to-year
variability in weather conditions. The dotted line shows the trend in observed values at
monitoring sites, while the solid line illustrates the underlying ozone trend after removing
the effects of weather. The solid line serves as a m ore accurate ozone trend for assessing
changes in emissions. Typical weather conditions are determined by averaging
conditions (e.g., temperature, humidity, etc.) for the time period presented. The
information provided is useful for reviewing the weather influence for a particular ozone
season. The solid line represents ozone levels anticipated under typical weather
conditions.
Seasonal Average 8-hour Ozone Trends
Youngstown, OH 8-hr Ozone Trends
.Q
CL
CL
d) 80
c
o
N
o
SI 60
O)
CO
L.
CD
- 40
CO
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o,
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20
Adjusted for Weather
Unadjusted for Weather
1998
2000
2002
Year
2004
2006
-------
Akron, OH 8-hr Ozone Trends
n
CL
CL
0 80
c
o
M
o
0 60
O)
CO
L.
-------
Cleveland, OH 8-hr Ozone Trends
-Q
L
CL
0 80
c
o
N
O
a) 60
O)
(0
L.
0
5 40
CO
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w
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o
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Unadjusted for Weather
1998
2000
2002
Year
2004
2006
Columbus,OH 8-hr Ozone Trends
n
CL
CL
0 80
c
o
N
O
a) 60
D)
03
L.
CD
f: 40
co
c
o
C0
TO
-------
Dayton, OH 8-hr Ozone Trends
.Q
CL
CL
(U
c
o
N
o
Š 60
O)
CO
L.
0
f; 40
(0
c
o
-------
Lykens, OH
80
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Q_
Q-
0
C
o
N
O
0 60
D)
ra
!_
0
- 40
ra
c
o
CO
0
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Adjusted for Weather
Unadjusted for Weather
* Š*
*
o..
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r- °
20
1998
2000
2002
Year
2004
2006
Oxford, OH
.Q
CL
Q.
0 80
c
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N
O
O)
(0
L.
0
1: 40
CO
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o
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ro
0
c/)
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20
Adjusted for Weather
Unadjusted for Weather
O- Ģ
- .
o
-I
. o"
o
- o*
-2-
1998
2000
2002
Year
2004
2006
-------
Toledo, OH 8-hr Ozone I rends
_Q
Q_
Q.
a) 80
ŖZ
o
N
o
Q) 60
O)
CO
L.
-------
Wisconsin
Ozone
On average, ozone adjusted for weather conditions declined 13 percent between 1997 and
2007. These improvements in ozone are in response to both state and regional reductions
in NOx and VOC emissions. The level of ozone improvement varies from site to site.
Trends for 1997-2007 for rural sites and urban areas with complete ozone and
meteorology data are presented below. Ozone season (May 1 - September 30) averages
of daily maximum 8-hour ozone were adjusted to remove the influence of year-to-year
variability in weather conditions. The dotted line shows the trend in observed values at
monitoring sites, while the solid line illustrates the underlying ozone trend after removing
the effects of weather. The solid line serves as a m ore accurate ozone trend for assessing
changes in emissions. Typical weather conditions are determined by averaging
conditions (e.g., temperature, humidity, etc.) for the time period presented. The
information provided is useful for reviewing the weather influence for a particular ozone
season. The solid line represents ozone levels anticipated under typical weather
conditions.
Seasonal Average 8-hour Ozone Trends
Milwaukee, Wl 8-hr Ozone Trends
n
CL
Q.
d) 80
c
o
N
o
Ž 60
O)
2
CD
- 40
CO
c
o
{/)
CO
0
10
o'
^0 m %
20
Adjusted for Weather
Unadjusted for Weather
1998 2000 2002
2004 2006
Year
-------
Madison, WI 8-hr Ozone Trends
JD
Q_
Q_
0 80
c
o
N
o
60
0)
CO
0
- 40-
(0
C
o
(f)
as
------- |