AQSQID: 840250170010

Site Name: Chelmsfordnr

Location: Chelmsford, MA

Reporting: True, Located: True

Current AQI: 67.0

Chelmsford MA, US: 42.612113, -71.307519

Date Observed (UTC) NOX NO NOY NO2 NO2Y SO2 OZONE CO PM10 PM2.5 AQI AQI/500
July 20, 2019, 6 a.m. 12.0 ppb (11) 3.0 ppb (3) N/A 9.0 ppb (8) N/A N/A 34.0 ppb (26) N/A N/A 20.0 μg/m3 (67) 67.0
 
July 20, 2019, 5 a.m. 10.0 ppb (9) 2.0 ppb (2) N/A 9.0 ppb (8) N/A N/A 40.0 ppb (31) N/A N/A 14.0 μg/m3 (54) 54.0
 
July 20, 2019, 4 a.m. 15.0 ppb (14) 3.0 ppb (3) N/A 12.0 ppb (11) N/A N/A 33.0 ppb (25) N/A N/A 17.0 μg/m3 (61) 61.0
 
July 20, 2019, 3 a.m. 18.0 ppb (17) 5.0 ppb (5) N/A 13.0 ppb (12) N/A N/A 27.0 ppb (21) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 20, 2019, 2 a.m. 23.0 ppb (21) 6.0 ppb (6) N/A 17.0 ppb (16) N/A N/A 28.0 ppb (22) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 20, 2019, 1 a.m. 22.0 ppb (20) 6.0 ppb (6) N/A 16.0 ppb (15) N/A N/A 29.0 ppb (22) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 20, 2019, midnight 18.0 ppb (17) 5.0 ppb (5) N/A 13.0 ppb (12) N/A N/A 29.0 ppb (22) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 19, 2019, 11 p.m. 20.0 ppb (19) 6.0 ppb (6) N/A 14.0 ppb (13) N/A N/A 33.0 ppb (25) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 19, 2019, 10 p.m. 12.0 ppb (11) 4.0 ppb (4) N/A 8.0 ppb (7) N/A N/A 36.0 ppb (28) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 19, 2019, 9 p.m. 11.0 ppb (10) 4.0 ppb (4) N/A 7.0 ppb (6) N/A N/A 38.0 ppb (29) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 19, 2019, 8 p.m. 13.0 ppb (12) 5.0 ppb (5) N/A 7.0 ppb (6) N/A N/A 37.0 ppb (28) N/A N/A 13.0 μg/m3 (52) 52.0
 
July 19, 2019, 7 p.m. 13.0 ppb (12) 6.0 ppb (6) N/A 7.0 ppb (6) N/A N/A 33.0 ppb (25) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 19, 2019, 6 p.m. 24.0 ppb (22) 13.0 ppb (12) N/A 11.0 ppb (10) N/A N/A 29.0 ppb (22) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 19, 2019, 5 p.m. 24.0 ppb (22) 11.0 ppb (10) N/A 14.0 ppb (13) N/A N/A 37.0 ppb (28) N/A N/A 6.0 μg/m3 (25) 28.0
 
July 19, 2019, 4 p.m. 21.0 ppb (19) 9.0 ppb (8) N/A 12.0 ppb (11) N/A N/A 36.0 ppb (28) N/A N/A 5.0 μg/m3 (21) 28.0
 
July 19, 2019, 3 p.m. 20.0 ppb (19) 10.0 ppb (9) N/A 10.0 ppb (9) N/A N/A 32.0 ppb (25) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 19, 2019, 2 p.m. 30.0 ppb (28) 17.0 ppb (16) N/A 13.0 ppb (12) N/A N/A 23.0 ppb (18) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 19, 2019, 1 p.m. 33.0 ppb (31) 19.0 ppb (18) N/A 13.0 ppb (12) N/A N/A 15.0 ppb (12) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 19, 2019, noon 37.0 ppb (34) 24.0 ppb (22) N/A 13.0 ppb (12) N/A N/A 8.0 ppb (6) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 19, 2019, 11 a.m. 40.0 ppb (37) 27.0 ppb (25) N/A 12.0 ppb (11) N/A N/A 5.0 ppb (4) N/A N/A 7.0 μg/m3 (29) 37.0
 
July 19, 2019, 10 a.m. 8.0 ppb (7) 3.0 ppb (3) N/A 5.0 ppb (5) N/A N/A 11.0 ppb (8) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 19, 2019, 9 a.m. 3.0 ppb (3) 1.0 ppb (1) N/A 2.0 ppb (2) N/A N/A 16.0 ppb (12) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 19, 2019, 8 a.m. 6.0 ppb (6) 1.0 ppb (1) N/A 5.0 ppb (5) N/A N/A 12.0 ppb (9) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 19, 2019, 7 a.m. 12.0 ppb (11) 2.0 ppb (2) N/A 10.0 ppb (9) N/A N/A 4.0 ppb (3) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 19, 2019, 6 a.m. 14.0 ppb (13) 3.0 ppb (3) N/A 12.0 ppb (11) N/A N/A 4.0 ppb (3) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 19, 2019, 5 a.m. 31.0 ppb (29) 16.0 ppb (15) N/A 16.0 ppb (15) N/A N/A 2.0 ppb (2) N/A N/A 5.0 μg/m3 (21) 29.0
 
July 19, 2019, 4 a.m. 60.0 ppb (56) 41.0 ppb (38) N/A 19.0 ppb (18) N/A N/A 2.0 ppb (2) N/A N/A 6.0 μg/m3 (25) 56.0
 
July 19, 2019, 3 a.m. 26.0 ppb (24) 8.0 ppb (7) N/A 18.0 ppb (17) N/A N/A 2.0 ppb (2) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 19, 2019, 2 a.m. 27.0 ppb (25) 12.0 ppb (11) N/A 15.0 ppb (14) N/A N/A 7.0 ppb (5) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 19, 2019, 1 a.m. 15.0 ppb (14) 5.0 ppb (5) N/A 10.0 ppb (9) N/A N/A 13.0 ppb (10) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 19, 2019, midnight 6.0 ppb (6) 2.0 ppb (2) N/A 5.0 ppb (5) N/A N/A 20.0 ppb (15) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 18, 2019, 11 p.m. 14.0 ppb (13) 7.0 ppb (6) N/A 8.0 ppb (7) N/A N/A 18.0 ppb (14) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 18, 2019, 10 p.m. 8.0 ppb (7) 2.0 ppb (2) N/A 6.0 ppb (6) N/A N/A 21.0 ppb (16) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 18, 2019, 9 p.m. 6.0 ppb (6) 2.0 ppb (2) N/A 4.0 ppb (4) N/A N/A 24.0 ppb (18) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 18, 2019, 8 p.m. 13.0 ppb (12) 6.0 ppb (6) N/A 8.0 ppb (7) N/A N/A 21.0 ppb (16) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 18, 2019, 7 p.m. 14.0 ppb (13) 7.0 ppb (6) N/A 7.0 ppb (6) N/A N/A 23.0 ppb (18) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 18, 2019, 6 p.m. 12.0 ppb (11) 6.0 ppb (6) N/A 6.0 ppb (6) N/A N/A 23.0 ppb (18) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 18, 2019, 5 p.m. 18.0 ppb (17) 10.0 ppb (9) N/A 8.0 ppb (7) N/A N/A 19.0 ppb (15) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 18, 2019, 4 p.m. 7.0 ppb (6) 4.0 ppb (4) N/A 3.0 ppb (3) N/A N/A 23.0 ppb (18) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 18, 2019, 3 p.m. 11.0 ppb (10) 6.0 ppb (6) N/A 5.0 ppb (5) N/A N/A 20.0 ppb (15) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 18, 2019, 2 p.m. 15.0 ppb (14) 8.0 ppb (7) N/A 7.0 ppb (6) N/A N/A 18.0 ppb (14) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 18, 2019, 1 p.m. 5.0 ppb (5) 3.0 ppb (3) N/A 3.0 ppb (3) N/A N/A 20.0 ppb (15) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 18, 2019, noon 5.0 ppb (5) 3.0 ppb (3) N/A 3.0 ppb (3) N/A N/A 19.0 ppb (15) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 18, 2019, 11 a.m. 5.0 ppb (5) 2.0 ppb (2) N/A 2.0 ppb (2) N/A N/A 17.0 ppb (13) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 18, 2019, 10 a.m. 7.0 ppb (6) 3.0 ppb (3) N/A 4.0 ppb (4) N/A N/A 15.0 ppb (12) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 18, 2019, 9 a.m. 8.0 ppb (7) 3.0 ppb (3) N/A 6.0 ppb (6) N/A N/A 10.0 ppb (8) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 18, 2019, 8 a.m. 3.0 ppb (3) 2.0 ppb (2) N/A 1.0 ppb (1) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 29.0
 
July 18, 2019, 7 a.m. N/A N/A N/A N/A N/A N/A 6.0 ppb (5) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 18, 2019, 6 a.m. N/A N/A N/A N/A N/A N/A 4.0 ppb (3) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 18, 2019, 5 a.m. N/A N/A N/A N/A N/A N/A 4.0 ppb (3) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 18, 2019, 4 a.m. 26.0 ppb (24) 16.0 ppb (15) N/A 10.0 ppb (9) N/A N/A 4.0 ppb (3) N/A N/A 5.0 μg/m3 (21) 24.0
 
July 18, 2019, 3 a.m. 14.0 ppb (13) 6.0 ppb (6) N/A 8.0 ppb (7) N/A N/A 4.0 ppb (3) N/A N/A 5.0 μg/m3 (21) 21.0
 
July 18, 2019, 2 a.m. 11.0 ppb (10) 4.0 ppb (4) N/A 7.0 ppb (6) N/A N/A 6.0 ppb (5) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 18, 2019, 1 a.m. 17.0 ppb (16) 5.0 ppb (5) N/A 11.0 ppb (10) N/A N/A 8.0 ppb (6) N/A N/A 4.0 μg/m3 (17) 17.0
 
July 18, 2019, midnight 25.0 ppb (23) 10.0 ppb (9) N/A 15.0 ppb (14) N/A N/A 9.0 ppb (7) N/A N/A 4.0 μg/m3 (17) 23.0
 
July 17, 2019, 11 p.m. 20.0 ppb (19) 9.0 ppb (8) N/A 11.0 ppb (10) N/A N/A 16.0 ppb (12) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 17, 2019, 10 p.m. 40.0 ppb (37) 22.0 ppb (20) N/A 18.0 ppb (17) N/A N/A 12.0 ppb (9) N/A N/A 7.0 μg/m3 (29) 37.0
 
July 17, 2019, 9 p.m. 15.0 ppb (14) 5.0 ppb (5) N/A 9.0 ppb (8) N/A N/A 20.0 ppb (15) N/A N/A 4.0 μg/m3 (17) 17.0
 
July 17, 2019, 8 p.m. 8.0 ppb (7) 4.0 ppb (4) N/A 5.0 ppb (5) N/A N/A 32.0 ppb (25) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 17, 2019, 7 p.m. 6.0 ppb (6) 2.0 ppb (2) N/A 4.0 ppb (4) N/A N/A 37.0 ppb (28) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 17, 2019, 6 p.m. 16.0 ppb (15) 7.0 ppb (6) N/A 9.0 ppb (8) N/A N/A 37.0 ppb (28) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 17, 2019, 5 p.m. 20.0 ppb (19) 8.0 ppb (7) N/A 12.0 ppb (11) N/A N/A 34.0 ppb (26) N/A N/A N/A 26.0
 
July 17, 2019, 4 p.m. 27.0 ppb (25) 11.0 ppb (10) N/A 15.0 ppb (14) N/A N/A 32.0 ppb (25) N/A N/A 12.0 μg/m3 (50) 50.0
 
July 17, 2019, 3 p.m. 25.0 ppb (23) 10.0 ppb (9) N/A 15.0 ppb (14) N/A N/A 31.0 ppb (24) N/A N/A 13.0 μg/m3 (52) 52.0
 
July 17, 2019, 2 p.m. 37.0 ppb (34) 17.0 ppb (16) N/A 21.0 ppb (19) N/A N/A 19.0 ppb (15) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 17, 2019, 1 p.m. 34.0 ppb (31) 15.0 ppb (14) N/A 19.0 ppb (18) N/A N/A 19.0 ppb (15) N/A N/A 13.0 μg/m3 (52) 52.0
 
July 17, 2019, noon 38.0 ppb (35) 16.0 ppb (15) N/A 23.0 ppb (21) N/A N/A 17.0 ppb (13) N/A N/A 13.0 μg/m3 (52) 52.0
 
July 17, 2019, 11 a.m. 38.0 ppb (35) 15.0 ppb (14) N/A 23.0 ppb (21) N/A N/A 18.0 ppb (14) N/A N/A 15.0 μg/m3 (56) 56.0
 
July 17, 2019, 10 a.m. 41.0 ppb (38) 16.0 ppb (15) N/A 26.0 ppb (24) N/A N/A 22.0 ppb (17) N/A N/A 12.0 μg/m3 (50) 50.0
 
July 17, 2019, 9 a.m. 34.0 ppb (31) 9.0 ppb (8) N/A 25.0 ppb (23) N/A N/A 25.0 ppb (19) N/A N/A 15.0 μg/m3 (56) 56.0
 
July 17, 2019, 8 a.m. 27.0 ppb (25) 5.0 ppb (5) N/A 22.0 ppb (20) N/A N/A 31.0 ppb (24) N/A N/A 13.0 μg/m3 (52) 52.0
 
July 17, 2019, 7 a.m. 24.0 ppb (22) 4.0 ppb (4) N/A 20.0 ppb (19) N/A N/A 39.0 ppb (30) N/A N/A 15.0 μg/m3 (56) 56.0
 
July 17, 2019, 6 a.m. 15.0 ppb (14) 2.0 ppb (2) N/A 13.0 ppb (12) N/A N/A 52.0 ppb (40) N/A N/A 16.0 μg/m3 (59) 59.0
 
July 17, 2019, 5 a.m. 22.0 ppb (20) 3.0 ppb (3) N/A 19.0 ppb (18) N/A N/A 51.0 ppb (39) N/A N/A 14.0 μg/m3 (54) 54.0
 
July 17, 2019, 4 a.m. 25.0 ppb (23) 4.0 ppb (4) N/A 20.0 ppb (19) N/A N/A 51.0 ppb (39) N/A N/A 15.0 μg/m3 (56) 56.0
 
July 17, 2019, 3 a.m. 23.0 ppb (21) 4.0 ppb (4) N/A 19.0 ppb (18) N/A N/A 46.0 ppb (35) N/A N/A 15.0 μg/m3 (56) 56.0
 
July 17, 2019, 2 a.m. 23.0 ppb (21) 5.0 ppb (5) N/A 18.0 ppb (17) N/A N/A 42.0 ppb (32) N/A N/A 14.0 μg/m3 (54) 54.0
 
July 17, 2019, 1 a.m. 25.0 ppb (23) 7.0 ppb (6) N/A 18.0 ppb (17) N/A N/A 28.0 ppb (22) N/A N/A 14.0 μg/m3 (54) 54.0
 
July 17, 2019, midnight 36.0 ppb (33) 12.0 ppb (11) N/A 24.0 ppb (22) N/A N/A 23.0 ppb (18) N/A N/A 12.0 μg/m3 (50) 50.0
 
July 16, 2019, 11 p.m. 24.0 ppb (22) 6.0 ppb (6) N/A 18.0 ppb (17) N/A N/A 33.0 ppb (25) N/A N/A 13.0 μg/m3 (52) 52.0
 
July 16, 2019, 10 p.m. 30.0 ppb (28) 11.0 ppb (10) N/A 19.0 ppb (18) N/A N/A 33.0 ppb (25) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 16, 2019, 9 p.m. 29.0 ppb (27) 11.0 ppb (10) N/A 17.0 ppb (16) N/A N/A 35.0 ppb (27) N/A N/A 12.0 μg/m3 (50) 50.0
 
July 16, 2019, 8 p.m. 11.0 ppb (10) 4.0 ppb (4) N/A 7.0 ppb (6) N/A N/A 36.0 ppb (28) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 16, 2019, 7 p.m. 9.0 ppb (8) 3.0 ppb (3) N/A 6.0 ppb (6) N/A N/A 32.0 ppb (25) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 16, 2019, 6 p.m. 22.0 ppb (20) 11.0 ppb (10) N/A 11.0 ppb (10) N/A N/A 27.0 ppb (21) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 16, 2019, 5 p.m. 22.0 ppb (20) 11.0 ppb (10) N/A 11.0 ppb (10) N/A N/A 31.0 ppb (24) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 16, 2019, 4 p.m. 19.0 ppb (18) 8.0 ppb (7) N/A 11.0 ppb (10) N/A N/A 37.0 ppb (28) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 16, 2019, 3 p.m. 25.0 ppb (23) 14.0 ppb (13) N/A 12.0 ppb (11) N/A N/A 26.0 ppb (20) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 16, 2019, 2 p.m. 25.0 ppb (23) 13.0 ppb (12) N/A 12.0 ppb (11) N/A N/A 26.0 ppb (20) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 16, 2019, 1 p.m. 37.0 ppb (34) 22.0 ppb (20) N/A 16.0 ppb (15) N/A N/A 19.0 ppb (15) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 16, 2019, noon 13.0 ppb (12) 6.0 ppb (6) N/A 7.0 ppb (6) N/A N/A 14.0 ppb (11) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 16, 2019, 11 a.m. 11.0 ppb (10) 6.0 ppb (6) N/A 6.0 ppb (6) N/A N/A 10.0 ppb (8) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 16, 2019, 10 a.m. 36.0 ppb (33) 27.0 ppb (25) N/A 9.0 ppb (8) N/A N/A 2.0 ppb (2) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 16, 2019, 9 a.m. 41.0 ppb (38) 29.0 ppb (27) N/A 12.0 ppb (11) N/A N/A 2.0 ppb (2) N/A N/A 8.0 μg/m3 (33) 38.0
 
July 16, 2019, 8 a.m. 20.0 ppb (19) 8.0 ppb (7) N/A 11.0 ppb (10) N/A N/A 3.0 ppb (2) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 16, 2019, 7 a.m. 18.0 ppb (17) 7.0 ppb (6) N/A 11.0 ppb (10) N/A N/A 4.0 ppb (3) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 16, 2019, 6 a.m. 12.0 ppb (11) 5.0 ppb (5) N/A 7.0 ppb (6) N/A N/A 9.0 ppb (7) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 16, 2019, 5 a.m. 12.0 ppb (11) 5.0 ppb (5) N/A 7.0 ppb (6) N/A N/A 13.0 ppb (10) N/A N/A 12.0 μg/m3 (50) 50.0
 
July 16, 2019, 4 a.m. 32.0 ppb (30) 16.0 ppb (15) N/A 16.0 ppb (15) N/A N/A 5.0 ppb (4) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 16, 2019, 3 a.m. 9.0 ppb (8) 5.0 ppb (5) N/A 4.0 ppb (4) N/A N/A 17.0 ppb (13) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 16, 2019, 2 a.m. 5.0 ppb (5) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 19.0 ppb (15) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 16, 2019, 1 a.m. 5.0 ppb (5) 2.0 ppb (2) N/A 3.0 ppb (3) N/A N/A 21.0 ppb (16) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 16, 2019, midnight 10.0 ppb (9) 5.0 ppb (5) N/A 5.0 ppb (5) N/A N/A 22.0 ppb (17) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 15, 2019, 11 p.m. 6.0 ppb (6) 3.0 ppb (3) N/A 3.0 ppb (3) N/A N/A 25.0 ppb (19) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 15, 2019, 10 p.m. 6.0 ppb (6) 4.0 ppb (4) N/A 2.0 ppb (2) N/A N/A 27.0 ppb (21) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 15, 2019, 9 p.m. 6.0 ppb (6) 4.0 ppb (4) N/A 2.0 ppb (2) N/A N/A 27.0 ppb (21) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 15, 2019, 8 p.m. 6.0 ppb (6) 4.0 ppb (4) N/A 2.0 ppb (2) N/A N/A 28.0 ppb (22) N/A N/A 5.0 μg/m3 (21) 22.0
 
July 15, 2019, 7 p.m. 7.0 ppb (6) 5.0 ppb (5) N/A 2.0 ppb (2) N/A N/A 27.0 ppb (21) N/A N/A 3.0 μg/m3 (12) 21.0
 
July 15, 2019, 6 p.m. 7.0 ppb (6) 5.0 ppb (5) N/A 3.0 ppb (3) N/A N/A 27.0 ppb (21) N/A N/A 3.0 μg/m3 (12) 21.0
 
July 15, 2019, 5 p.m. 14.0 ppb (13) 10.0 ppb (9) N/A 4.0 ppb (4) N/A N/A 25.0 ppb (19) N/A N/A 4.0 μg/m3 (17) 19.0
 
July 15, 2019, 4 p.m. 7.0 ppb (6) 5.0 ppb (5) N/A 2.0 ppb (2) N/A N/A 26.0 ppb (20) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 15, 2019, 3 p.m. 8.0 ppb (7) 6.0 ppb (6) N/A 3.0 ppb (3) N/A N/A 26.0 ppb (20) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 15, 2019, 2 p.m. 9.0 ppb (8) 6.0 ppb (6) N/A 3.0 ppb (3) N/A N/A 25.0 ppb (19) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 15, 2019, 1 p.m. 11.0 ppb (10) 7.0 ppb (6) N/A 4.0 ppb (4) N/A N/A 23.0 ppb (18) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 15, 2019, noon 12.0 ppb (11) 8.0 ppb (7) N/A 4.0 ppb (4) N/A N/A 20.0 ppb (15) N/A N/A 6.0 μg/m3 (25) 25.0
 
July 15, 2019, 11 a.m. 10.0 ppb (9) 5.0 ppb (5) N/A 5.0 ppb (5) N/A N/A 14.0 ppb (11) N/A N/A 3.0 μg/m3 (12) 12.0
 
July 15, 2019, 10 a.m. 14.0 ppb (13) 5.0 ppb (5) N/A 9.0 ppb (8) N/A N/A 6.0 ppb (5) N/A N/A 2.0 μg/m3 (8) 13.0
 
July 15, 2019, 9 a.m. 5.0 ppb (5) 2.0 ppb (2) N/A 3.0 ppb (3) N/A N/A 15.0 ppb (12) N/A N/A 5.0 μg/m3 (21) 21.0
 
July 15, 2019, 8 a.m. 5.0 ppb (5) 2.0 ppb (2) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 8.0 μg/m3 (33) 33.0
 
July 15, 2019, 7 a.m. N/A N/A N/A N/A N/A N/A 19.0 ppb (15) N/A N/A 5.0 μg/m3 (21) 21.0
 
July 15, 2019, 6 a.m. N/A N/A N/A N/A N/A N/A 17.0 ppb (13) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 15, 2019, 5 a.m. N/A N/A N/A N/A N/A N/A 17.0 ppb (13) N/A N/A 4.0 μg/m3 (17) 17.0
 
July 15, 2019, 4 a.m. 5.0 ppb (5) 4.0 ppb (4) N/A 2.0 ppb (2) N/A N/A 19.0 ppb (15) N/A N/A 5.0 μg/m3 (21) 21.0
 
July 15, 2019, 3 a.m. 3.0 ppb (3) 2.0 ppb (2) N/A 1.0 ppb (1) N/A N/A 21.0 ppb (16) N/A N/A 5.0 μg/m3 (21) 21.0
 
July 15, 2019, 2 a.m. 9.0 ppb (8) 4.0 ppb (4) N/A 4.0 ppb (4) N/A N/A 20.0 ppb (15) N/A N/A 5.0 μg/m3 (21) 21.0
 
July 15, 2019, 1 a.m. 3.0 ppb (3) 2.0 ppb (2) N/A 1.0 ppb (1) N/A N/A 22.0 ppb (17) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 15, 2019, midnight 3.0 ppb (3) 2.0 ppb (2) N/A 2.0 ppb (2) N/A N/A 25.0 ppb (19) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 14, 2019, 11 p.m. 3.0 ppb (3) 2.0 ppb (2) N/A 2.0 ppb (2) N/A N/A 30.0 ppb (23) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 14, 2019, 10 p.m. 5.0 ppb (5) 3.0 ppb (3) N/A 2.0 ppb (2) N/A N/A 32.0 ppb (25) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 14, 2019, 9 p.m. 5.0 ppb (5) 3.0 ppb (3) N/A 2.0 ppb (2) N/A N/A 34.0 ppb (26) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 14, 2019, 8 p.m. 2.0 ppb (2) 2.0 ppb (2) N/A 0.0 ppb (0) N/A N/A 37.0 ppb (28) N/A N/A 12.0 μg/m3 (50) 50.0
 
July 14, 2019, 7 p.m. 3.0 ppb (3) 2.0 ppb (2) N/A 1.0 ppb (1) N/A N/A 38.0 ppb (29) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 14, 2019, 6 p.m. 4.0 ppb (4) 2.0 ppb (2) N/A 2.0 ppb (2) N/A N/A 38.0 ppb (29) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 14, 2019, 5 p.m. 3.0 ppb (3) 2.0 ppb (2) N/A 1.0 ppb (1) N/A N/A 38.0 ppb (29) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 14, 2019, 4 p.m. 2.0 ppb (2) 2.0 ppb (2) N/A 0.0 ppb (0) N/A N/A 38.0 ppb (29) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 14, 2019, 3 p.m. 4.0 ppb (4) 2.0 ppb (2) N/A 2.0 ppb (2) N/A N/A 39.0 ppb (30) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 14, 2019, 2 p.m. 5.0 ppb (5) 3.0 ppb (3) N/A 3.0 ppb (3) N/A N/A 40.0 ppb (31) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 14, 2019, 1 p.m. 4.0 ppb (4) 2.0 ppb (2) N/A 2.0 ppb (2) N/A N/A 40.0 ppb (31) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 14, 2019, noon 5.0 ppb (5) 2.0 ppb (2) N/A 3.0 ppb (3) N/A N/A 32.0 ppb (25) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 14, 2019, 11 a.m. 7.0 ppb (6) 3.0 ppb (3) N/A 4.0 ppb (4) N/A N/A 21.0 ppb (16) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 14, 2019, 10 a.m. 7.0 ppb (6) 3.0 ppb (3) N/A 4.0 ppb (4) N/A N/A 14.0 ppb (11) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 14, 2019, 9 a.m. 5.0 ppb (5) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 14.0 ppb (11) N/A N/A 12.0 μg/m3 (50) 50.0
 
July 14, 2019, 8 a.m. 4.0 ppb (4) 1.0 ppb (1) N/A 3.0 ppb (3) N/A N/A 20.0 ppb (15) N/A N/A 12.0 μg/m3 (50) 50.0
 
July 14, 2019, 7 a.m. 6.0 ppb (6) 2.0 ppb (2) N/A 4.0 ppb (4) N/A N/A 19.0 ppb (15) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 14, 2019, 6 a.m. 9.0 ppb (8) 1.0 ppb (1) N/A 8.0 ppb (7) N/A N/A 13.0 ppb (10) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 14, 2019, 5 a.m. 12.0 ppb (11) 3.0 ppb (3) N/A 9.0 ppb (8) N/A N/A 14.0 ppb (11) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 14, 2019, 4 a.m. 7.0 ppb (6) 1.0 ppb (1) N/A 6.0 ppb (6) N/A N/A 17.0 ppb (13) N/A N/A 15.0 μg/m3 (56) 56.0
 
July 14, 2019, 3 a.m. 22.0 ppb (20) 7.0 ppb (6) N/A 15.0 ppb (14) N/A N/A 10.0 ppb (8) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 14, 2019, 2 a.m. 9.0 ppb (8) 2.0 ppb (2) N/A 8.0 ppb (7) N/A N/A 18.0 ppb (14) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 14, 2019, 1 a.m. 11.0 ppb (10) 3.0 ppb (3) N/A 8.0 ppb (7) N/A N/A 21.0 ppb (16) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 14, 2019, midnight 10.0 ppb (9) 3.0 ppb (3) N/A 7.0 ppb (6) N/A N/A 24.0 ppb (18) N/A N/A 11.0 μg/m3 (46) 46.0
 
July 13, 2019, 11 p.m. 10.0 ppb (9) 3.0 ppb (3) N/A 6.0 ppb (6) N/A N/A 28.0 ppb (22) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 13, 2019, 10 p.m. 5.0 ppb (5) 2.0 ppb (2) N/A 3.0 ppb (3) N/A N/A 33.0 ppb (25) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 13, 2019, 9 p.m. 6.0 ppb (6) 3.0 ppb (3) N/A 3.0 ppb (3) N/A N/A 34.0 ppb (26) N/A N/A 7.0 μg/m3 (29) 29.0
 
July 13, 2019, 8 p.m. 7.0 ppb (6) 3.0 ppb (3) N/A 4.0 ppb (4) N/A N/A 35.0 ppb (27) N/A N/A 9.0 μg/m3 (38) 38.0
 
July 13, 2019, 7 p.m. 3.0 ppb (3) 2.0 ppb (2) N/A 1.0 ppb (1) N/A N/A 37.0 ppb (28) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 13, 2019, 6 p.m. 6.0 ppb (6) 4.0 ppb (4) N/A 3.0 ppb (3) N/A N/A 35.0 ppb (27) N/A N/A 8.0 μg/m3 (33) 33.0
 
July 13, 2019, 5 p.m. 3.0 ppb (3) 2.0 ppb (2) N/A 1.0 ppb (1) N/A N/A 35.0 ppb (27) N/A N/A 5.0 μg/m3 (21) 27.0
 
July 13, 2019, 4 p.m. 5.0 ppb (5) 3.0 ppb (3) N/A 2.0 ppb (2) N/A N/A 35.0 ppb (27) N/A N/A 17.0 μg/m3 (61) 61.0
 
July 13, 2019, 3 p.m. 3.0 ppb (3) 2.0 ppb (2) N/A 1.0 ppb (1) N/A N/A 36.0 ppb (28) N/A N/A 13.0 μg/m3 (52) 52.0
 
July 13, 2019, 2 p.m. 3.0 ppb (3) 2.0 ppb (2) N/A 1.0 ppb (1) N/A N/A 34.0 ppb (26) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 13, 2019, 1 p.m. 4.0 ppb (4) 3.0 ppb (3) N/A 2.0 ppb (2) N/A N/A 32.0 ppb (25) N/A N/A 10.0 μg/m3 (42) 42.0
 
July 13, 2019, noon 6.0 ppb (6) 4.0 ppb (4) N/A 3.0 ppb (3) N/A N/A 29.0 ppb (22) N/A N/A 12.0 μg/m3 (50) 50.0
 
July 13, 2019, 11 a.m. 3.0 ppb (3) 2.0 ppb (2) N/A 1.0 ppb (1) N/A N/A 22.0 ppb (17) N/A N/A 12.0 μg/m3 (50) 50.0
 
July 13, 2019, 10 a.m. 7.0 ppb (6) 3.0 ppb (3) N/A 4.0 ppb (4) N/A N/A 19.0 ppb (15) N/A N/A 17.0 μg/m3 (61) 61.0
 
July 13, 2019, 9 a.m. 4.0 ppb (4) 2.0 ppb (2) N/A 2.0 ppb (2) N/A N/A 22.0 ppb (17) N/A N/A 13.0 μg/m3 (52) 52.0
 
July 13, 2019, 8 a.m. 7.0 ppb (6) 3.0 ppb (3) N/A 4.0 ppb (4) N/A N/A 22.0 ppb (17) N/A N/A 12.0 μg/m3 (50) 50.0
 
July 13, 2019, 7 a.m. 9.0 ppb (8) 4.0 ppb (4) N/A 5.0 ppb (5) N/A N/A 17.0 ppb (13) N/A N/A 7.0 μg/m3 (29) 29.0