Attachment B

Distribution Charts of Days ≥0.060 ppm by Month and State

*Note: only those states not currently required to operate yearround are included.

The ambient ozone data in this document were compiled from 

analyses used in support of the proposed rule for the O3 NAAQS: 

Revisions to the Length of the Required O3 Monitoring Seasons

Docket ID No. EPA-HQ-OAR-2008-0699
11/12/2014 1

Current Season March - October 2/26 Monitors Year Round
11/12/2014 2

Current Season March - November 9/10 Monitors Year Round
11/12/2014 3

Current Season March - September 34/53 Monitors Year Round
11/12/2014 4

Current Season April - September 3/13 Monitors Year Round
11/12/2014 5

Current Season April - October 6/7 Monitors Year Round
11/12/2014 6

Current Season April - October 3/4 Monitors Year Round
11/12/2014 7

Current Season March - October 59/62 Monitors Year Round
11/12/2014 8

Current Season March - October 2/21 Monitors Year Round
11/12/2014 9

Current Season May - September 2/6 Monitors Year Round
11/12/2014 10

Current Season April - October 26/44 Monitors Year Round
11/12/2014 11

Current Season April - September 3/46 Monitors Year Round
11/12/2014 12

Current Season April - October 1/15 Monitors Year Round
11/12/2014 13

Current Season April - October 11/11 Monitors Year Round
11/12/2014 14

Current Season March - October 5/32 Monitors Year Round
11/12/2014 15

Current Season March - October

AQCR 019, 022

3/3 Monitors Year Round
11/12/2014 16

Current Season April - September 5/19 Monitors Year Round
11/12/2014 17

Current Season April - October 6/21 Monitors Year Round
11/12/2014 18

Current Season April - September 5/19 Monitors Year Round
11/12/2014 19

Current Season April - September 7/30 Monitors Year Round
11/12/2014 20

Current Season April - October 2/18 Monitors Year Round
11/12/2014 21

Current Season March - October 2/12 Monitors Year Round
11/12/2014 22

Current Season April - October 2/25 Monitors Year Round
11/12/2014 23

Current Season June - September 7/9 Monitors Year Round
11/12/2014 24

Current Season April - October 2/7 Monitors Year Round
11/12/2014 25

Current Season April - September 7/13 Monitors Year Round
11/12/2014 26

Current Season April - October 14/17 Monitors Year Round
11/12/2014 27

Current Season April - October 34/38 Monitors Year Round
11/12/2014 28

Current Season April - October 7/49 Monitors Year Round
11/12/2014 29

Current Season May - September 8/9 Monitors Year Round
11/12/2014 30

Current Season April - October 6/53 Monitors Year Round
11/12/2014 31

Current Season March - November 16/33 Monitors Year Round
11/12/2014 32

Current Season May - September 1/10 Monitors Year Round
11/12/2014 33

Current Season April - October 50/59 Monitors Year Round
11/12/2014 34

Current Season April - September 1/3 Monitors Year Round
11/12/2014 35

Current Season April - October 9/24 Monitors Year Round
11/12/2014 36

Current Season June - September 7/7 Monitors Year Round
11/12/2014 37

Current Season March - October 5/27 Monitors Year Round
11/12/2014 38

Current Season March - October 31/36 Monitors Year Round

AQCR 022, 210, 211, 212, 

215, 217, 218
11/12/2014 39

Current Season May - September 13/30 Monitors Year Round
11/12/2014 40

Current Season April - September 2/2 Monitors Year Round
11/12/2014 41

Current Season April - October 4/30 Monitors Year Round
11/12/2014 42

Current Season May - September 5/18 Monitors Year Round
11/12/2014 43

Current Season April - October 2/10 Monitors Year Round
11/12/2014 44

Current Season April 15 – October 15 5/37 Monitors Year Round

7 of 14 Days in

April Before 4/15 
11/12/2014 45

Current Season April - October 24/34 Monitors Year Round