AQSQID: 240270006

Site Name: Howard County Near Road

Location: Howard Co, MD

Reporting: True, Located: True

Current AQI: 34.0

Howard Co MD, US: 39.143197, -76.846192

Date Observed (UTC) NOX NO NOY NO2 NO2Y SO2 OZONE CO PM10 PM2.5 AQI AQI/500
March 20, 2019, 11 p.m. 37.1 ppb (34) 10.8 ppb (10) N/A 26.0 ppb (24) N/A N/A N/A 0.32 ppb (4) N/A 7.0 μg/m3 (29) 34.0
 
March 20, 2019, 10 p.m. 35.2 ppb (33) 11.5 ppb (11) N/A 24.0 ppb (22) N/A N/A N/A 0.3 ppb (3) N/A 11.0 μg/m3 (46) 46.0
 
March 20, 2019, 9 p.m. 32.0 ppb (30) 10.0 ppb (9) N/A 22.0 ppb (20) N/A N/A N/A 0.3 ppb (3) N/A 5.0 μg/m3 (21) 30.0
 
March 20, 2019, 8 p.m. 37.1 ppb (34) 12.6 ppb (12) N/A 25.0 ppb (23) N/A N/A N/A 0.29 ppb (3) N/A 5.0 μg/m3 (21) 34.0
 
March 20, 2019, 7 p.m. 37.1 ppb (34) 12.0 ppb (11) N/A 25.0 ppb (23) N/A N/A N/A 0.3 ppb (3) N/A 3.0 μg/m3 (12) 34.0
 
March 20, 2019, 6 p.m. 44.4 ppb (41) 14.6 ppb (14) N/A 30.0 ppb (28) N/A N/A N/A 0.26 ppb (3) N/A 5.0 μg/m3 (21) 41.0
 
March 20, 2019, 5 p.m. 40.7 ppb (38) 16.5 ppb (15) N/A 24.0 ppb (22) N/A N/A N/A 0.24 ppb (3) N/A 9.0 μg/m3 (38) 38.0
 
March 20, 2019, 4 p.m. 49.2 ppb (46) 22.1 ppb (20) N/A 27.0 ppb (25) N/A N/A N/A 0.28 ppb (3) N/A 7.0 μg/m3 (29) 46.0
 
March 20, 2019, 3 p.m. 55.5 ppb (52) 29.6 ppb (27) N/A 26.0 ppb (24) N/A N/A N/A 0.34 ppb (4) N/A 7.0 μg/m3 (29) 52.0
 
March 20, 2019, 2 p.m. 64.8 ppb (61) 36.8 ppb (34) N/A 28.0 ppb (26) N/A N/A N/A 0.41 ppb (5) N/A 9.0 μg/m3 (38) 61.0
 
March 20, 2019, 1 p.m. 82.8 ppb (81) 55.3 ppb (51) N/A 27.0 ppb (25) N/A N/A N/A 0.52 ppb (6) N/A 12.0 μg/m3 (50) 81.0
 
March 20, 2019, noon 75.1 ppb (72) 48.6 ppb (45) N/A 27.0 ppb (25) N/A N/A N/A 0.49 ppb (5) N/A 10.0 μg/m3 (42) 72.0
 
March 20, 2019, 11 a.m. 53.5 ppb (50) 29.1 ppb (27) N/A 24.0 ppb (22) N/A N/A N/A 0.34 ppb (4) N/A 9.0 μg/m3 (38) 50.0
 
March 20, 2019, 10 a.m. 45.6 ppb (42) 22.3 ppb (21) N/A 23.0 ppb (21) N/A N/A N/A 0.3 ppb (3) N/A 8.0 μg/m3 (33) 42.0
 
March 20, 2019, 9 a.m. 75.4 ppb (73) 48.5 ppb (45) N/A 27.0 ppb (25) N/A N/A N/A 0.32 ppb (4) N/A 5.0 μg/m3 (21) 73.0
 
March 20, 2019, 8 a.m. N/A N/A N/A N/A N/A N/A N/A 0.27 ppb (3) N/A 7.0 μg/m3 (29) 29.0
 
March 20, 2019, 7 a.m. 68.4 ppb (65) 40.9 ppb (38) N/A 28.0 ppb (26) N/A N/A N/A 0.31 ppb (3) N/A 6.0 μg/m3 (25) 65.0
 
March 20, 2019, 6 a.m. 27.8 ppb (26) 9.5 ppb (9) N/A 18.0 ppb (17) N/A N/A N/A 0.21 ppb (2) N/A 5.0 μg/m3 (21) 26.0
 
March 20, 2019, 5 a.m. 31.0 ppb (29) 10.9 ppb (10) N/A 20.0 ppb (19) N/A N/A N/A 0.23 ppb (3) N/A 4.0 μg/m3 (17) 29.0
 
March 20, 2019, 4 a.m. 27.0 ppb (25) 6.8 ppb (6) N/A 20.0 ppb (19) N/A N/A N/A 0.24 ppb (3) N/A 1.0 μg/m3 (4) 25.0
 
March 20, 2019, 3 a.m. 25.2 ppb (23) 6.2 ppb (6) N/A 19.0 ppb (18) N/A N/A N/A 0.27 ppb (3) N/A 1.0 μg/m3 (4) 23.0
 
March 20, 2019, 2 a.m. 24.0 ppb (22) 2.8 ppb (3) N/A 21.0 ppb (19) N/A N/A N/A 0.28 ppb (3) N/A 3.0 μg/m3 (12) 22.0
 
March 20, 2019, 1 a.m. 31.8 ppb (29) 7.3 ppb (7) N/A 25.0 ppb (23) N/A N/A N/A 0.32 ppb (4) N/A 6.0 μg/m3 (25) 29.0
 
March 20, 2019, midnight 39.9 ppb (37) 12.8 ppb (12) N/A 27.0 ppb (25) N/A N/A N/A 0.31 ppb (3) N/A 8.0 μg/m3 (33) 37.0
 
March 19, 2019, 11 p.m. 20.4 ppb (19) 6.2 ppb (6) N/A 14.0 ppb (13) N/A N/A N/A 0.26 ppb (3) N/A 9.0 μg/m3 (38) 38.0
 
March 19, 2019, 10 p.m. 10.4 ppb (10) 1.9 ppb (2) N/A 8.0 ppb (7) N/A N/A N/A 0.22 ppb (2) N/A 6.0 μg/m3 (25) 25.0
 
March 19, 2019, 9 p.m. 9.7 ppb (9) 1.1 ppb (1) N/A 9.0 ppb (8) N/A N/A N/A 0.21 ppb (2) N/A 3.0 μg/m3 (12) 12.0
 
March 19, 2019, 8 p.m. 15.7 ppb (15) 5.0 ppb (5) N/A 11.0 ppb (10) N/A N/A N/A 0.23 ppb (3) N/A 0.0 μg/m3 (0) 15.0
 
March 19, 2019, 7 p.m. 11.0 ppb (10) 1.3 ppb (1) N/A 10.0 ppb (9) N/A N/A N/A 0.21 ppb (2) N/A -2.0 μg/m3 (0) 10.0
 
March 19, 2019, 6 p.m. 18.5 ppb (17) 4.0 ppb (4) N/A 14.0 ppb (13) N/A N/A N/A 0.23 ppb (3) N/A 2.0 μg/m3 (8) 17.0
 
March 19, 2019, 5 p.m. N/A N/A N/A N/A N/A N/A N/A 0.26 ppb (3) N/A 4.0 μg/m3 (17) 17.0
 
March 19, 2019, 4 p.m. N/A N/A N/A N/A N/A N/A N/A 0.26 ppb (3) N/A 3.0 μg/m3 (12) 12.0
 
March 19, 2019, 3 p.m. 44.3 ppb (41) 17.3 ppb (16) N/A 27.0 ppb (25) N/A N/A N/A 0.29 ppb (3) N/A N/A 41.0
 
March 19, 2019, 2 p.m. 34.6 ppb (32) 14.8 ppb (14) N/A 20.0 ppb (19) N/A N/A N/A 0.27 ppb (3) N/A 8.0 μg/m3 (33) 33.0
 
March 19, 2019, 1 p.m. 37.5 ppb (35) 17.5 ppb (16) N/A 20.0 ppb (19) N/A N/A N/A 0.31 ppb (3) N/A 8.0 μg/m3 (33) 35.0
 
March 19, 2019, noon 67.8 ppb (65) 43.2 ppb (40) N/A 25.0 ppb (23) N/A N/A N/A 0.37 ppb (4) N/A 9.0 μg/m3 (38) 65.0
 
March 19, 2019, 11 a.m. 94.7 ppb (93) 65.6 ppb (62) N/A 29.0 ppb (27) N/A N/A N/A 0.34 ppb (4) N/A 7.0 μg/m3 (29) 93.0
 
March 19, 2019, 10 a.m. 52.7 ppb (49) 29.4 ppb (27) N/A 23.0 ppb (21) N/A N/A N/A 0.27 ppb (3) N/A 8.0 μg/m3 (33) 49.0
 
March 19, 2019, 9 a.m. 41.0 ppb (38) 21.3 ppb (20) N/A 20.0 ppb (19) N/A N/A N/A 0.24 ppb (3) N/A 12.0 μg/m3 (50) 50.0
 
March 19, 2019, 8 a.m. 37.0 ppb (34) 18.1 ppb (17) N/A 19.0 ppb (18) N/A N/A N/A 0.23 ppb (3) N/A 7.0 μg/m3 (29) 34.0
 
March 19, 2019, 7 a.m. 35.0 ppb (32) 15.4 ppb (14) N/A 20.0 ppb (19) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 32.0
 
March 19, 2019, 6 a.m. 51.7 ppb (48) 26.4 ppb (24) N/A 25.0 ppb (23) N/A N/A N/A 0.23 ppb (3) N/A 10.0 μg/m3 (42) 48.0
 
March 19, 2019, 5 a.m. 47.0 ppb (44) 24.4 ppb (23) N/A 23.0 ppb (21) N/A N/A N/A 0.24 ppb (3) N/A 10.0 μg/m3 (42) 44.0
 
March 19, 2019, 4 a.m. 23.9 ppb (22) 5.6 ppb (5) N/A 18.0 ppb (17) N/A N/A N/A N/A N/A 10.0 μg/m3 (42) 42.0
 
March 19, 2019, 3 a.m. 42.3 ppb (39) 14.2 ppb (13) N/A 28.0 ppb (26) N/A N/A N/A 0.21 ppb (2) N/A 9.0 μg/m3 (38) 39.0
 
March 19, 2019, 2 a.m. 45.7 ppb (42) 13.7 ppb (13) N/A 32.0 ppb (30) N/A N/A N/A 0.24 ppb (3) N/A 7.0 μg/m3 (29) 42.0
 
March 19, 2019, 1 a.m. 47.8 ppb (44) 16.1 ppb (15) N/A 32.0 ppb (30) N/A N/A N/A 0.27 ppb (3) N/A 8.0 μg/m3 (33) 44.0
 
March 19, 2019, midnight 40.6 ppb (38) 13.4 ppb (12) N/A 27.0 ppb (25) N/A N/A N/A 0.28 ppb (3) N/A 6.0 μg/m3 (25) 38.0
 
March 18, 2019, 11 p.m. 33.5 ppb (31) 11.0 ppb (10) N/A 22.0 ppb (20) N/A N/A N/A 0.27 ppb (3) N/A 9.0 μg/m3 (38) 38.0
 
March 18, 2019, 10 p.m. 18.8 ppb (17) 4.0 ppb (4) N/A 15.0 ppb (14) N/A N/A N/A 0.18 ppb (2) N/A 9.0 μg/m3 (38) 38.0
 
March 18, 2019, 9 p.m. 21.6 ppb (20) 5.6 ppb (5) N/A 16.0 ppb (15) N/A N/A N/A 0.19 ppb (2) N/A 7.0 μg/m3 (29) 29.0
 
March 18, 2019, 8 p.m. 20.4 ppb (19) 4.8 ppb (4) N/A 16.0 ppb (15) N/A N/A N/A 0.21 ppb (2) N/A 8.0 μg/m3 (33) 33.0
 
March 18, 2019, 7 p.m. 25.6 ppb (24) 7.9 ppb (7) N/A 18.0 ppb (17) N/A N/A N/A 0.23 ppb (3) N/A 7.0 μg/m3 (29) 29.0
 
March 18, 2019, 6 p.m. 28.1 ppb (26) 10.3 ppb (10) N/A 18.0 ppb (17) N/A N/A N/A 0.23 ppb (3) N/A 6.0 μg/m3 (25) 26.0
 
March 18, 2019, 5 p.m. 37.2 ppb (34) 16.3 ppb (15) N/A 21.0 ppb (19) N/A N/A N/A 0.25 ppb (3) N/A 6.0 μg/m3 (25) 34.0
 
March 18, 2019, 4 p.m. 41.0 ppb (38) 19.2 ppb (18) N/A 22.0 ppb (20) N/A N/A N/A 0.26 ppb (3) N/A 5.0 μg/m3 (21) 38.0
 
March 18, 2019, 3 p.m. 44.3 ppb (41) 21.7 ppb (20) N/A 23.0 ppb (21) N/A N/A N/A 0.27 ppb (3) N/A 7.0 μg/m3 (29) 41.0
 
March 18, 2019, 2 p.m. 44.4 ppb (41) 19.9 ppb (18) N/A 25.0 ppb (23) N/A N/A N/A 0.26 ppb (3) N/A 8.0 μg/m3 (33) 41.0
 
March 18, 2019, 1 p.m. 56.2 ppb (52) 27.4 ppb (25) N/A 29.0 ppb (27) N/A N/A N/A 0.29 ppb (3) N/A 7.0 μg/m3 (29) 52.0
 
March 18, 2019, noon 77.8 ppb (75) 43.4 ppb (40) N/A 34.0 ppb (31) N/A N/A N/A 0.43 ppb (5) N/A 12.0 μg/m3 (50) 75.0
 
March 18, 2019, 11 a.m. 53.8 ppb (50) 24.0 ppb (22) N/A 30.0 ppb (28) N/A N/A N/A 0.32 ppb (4) N/A 4.0 μg/m3 (17) 50.0
 
March 18, 2019, 10 a.m. 40.8 ppb (38) 14.2 ppb (13) N/A 27.0 ppb (25) N/A N/A N/A 0.24 ppb (3) N/A 6.0 μg/m3 (25) 38.0
 
March 18, 2019, 9 a.m. 40.3 ppb (37) 13.2 ppb (12) N/A 27.0 ppb (25) N/A N/A N/A 0.25 ppb (3) N/A 5.0 μg/m3 (21) 37.0
 
March 18, 2019, 8 a.m. N/A N/A N/A N/A N/A N/A N/A 0.26 ppb (3) N/A 7.0 μg/m3 (29) 29.0
 
March 18, 2019, 7 a.m. 38.3 ppb (35) 11.4 ppb (11) N/A 27.0 ppb (25) N/A N/A N/A 0.24 ppb (3) N/A 6.0 μg/m3 (25) 35.0
 
March 18, 2019, 6 a.m. 36.2 ppb (34) 11.3 ppb (10) N/A 25.0 ppb (23) N/A N/A N/A 0.26 ppb (3) N/A 4.0 μg/m3 (17) 34.0
 
March 18, 2019, 5 a.m. 38.3 ppb (35) 12.3 ppb (11) N/A 26.0 ppb (24) N/A N/A N/A 0.29 ppb (3) N/A 6.0 μg/m3 (25) 35.0
 
March 18, 2019, 4 a.m. 23.8 ppb (22) 7.7 ppb (7) N/A 16.0 ppb (15) N/A N/A N/A 0.27 ppb (3) N/A 6.0 μg/m3 (25) 25.0
 
March 18, 2019, 3 a.m. 18.3 ppb (17) 2.0 ppb (2) N/A 16.0 ppb (15) N/A N/A N/A 0.25 ppb (3) N/A 4.0 μg/m3 (17) 17.0
 
March 18, 2019, 2 a.m. 16.7 ppb (15) 2.3 ppb (2) N/A 14.0 ppb (13) N/A N/A N/A 0.24 ppb (3) N/A 5.0 μg/m3 (21) 21.0
 
March 18, 2019, 1 a.m. 17.5 ppb (16) 3.8 ppb (4) N/A 14.0 ppb (13) N/A N/A N/A 0.24 ppb (3) N/A 6.0 μg/m3 (25) 25.0
 
March 18, 2019, midnight 7.1 ppb (7) 0.8 ppb (1) N/A 6.0 ppb (6) N/A N/A N/A 0.19 ppb (2) N/A 7.0 μg/m3 (29) 29.0
 
March 17, 2019, 11 p.m. 9.4 ppb (9) 0.8 ppb (1) N/A 9.0 ppb (8) N/A N/A N/A 0.18 ppb (2) N/A 6.0 μg/m3 (25) 25.0
 
March 17, 2019, 10 p.m. 6.5 ppb (6) 1.0 ppb (1) N/A 5.0 ppb (5) N/A N/A N/A 0.17 ppb (2) N/A 4.0 μg/m3 (17) 17.0
 
March 17, 2019, 9 p.m. 5.1 ppb (5) 0.9 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.17 ppb (2) N/A 3.0 μg/m3 (12) 12.0
 
March 17, 2019, 8 p.m. 4.8 ppb (4) 0.9 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.17 ppb (2) N/A 1.0 μg/m3 (4) 4.0
 
March 17, 2019, 7 p.m. 4.8 ppb (4) 0.9 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.17 ppb (2) N/A 1.0 μg/m3 (4) 4.0
 
March 17, 2019, 6 p.m. 4.7 ppb (4) 0.8 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.17 ppb (2) N/A 0.0 μg/m3 (0) 4.0
 
March 17, 2019, 5 p.m. 4.6 ppb (4) 0.9 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.17 ppb (2) N/A -2.0 μg/m3 (0) 4.0
 
March 17, 2019, 4 p.m. 5.1 ppb (5) 0.9 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.17 ppb (2) N/A -2.0 μg/m3 (0) 5.0
 
March 17, 2019, 3 p.m. 5.2 ppb (5) 0.7 ppb (1) N/A 5.0 ppb (5) N/A N/A N/A 0.17 ppb (2) N/A 0.0 μg/m3 (0) 5.0
 
March 17, 2019, 2 p.m. 6.4 ppb (6) 0.8 ppb (1) N/A 6.0 ppb (6) N/A N/A N/A 0.17 ppb (2) N/A -2.0 μg/m3 (0) 6.0
 
March 17, 2019, 1 p.m. 9.4 ppb (9) 1.1 ppb (1) N/A 8.0 ppb (7) N/A N/A N/A 0.18 ppb (2) N/A 0.0 μg/m3 (0) 9.0
 
March 17, 2019, noon 23.1 ppb (21) 6.5 ppb (6) N/A 17.0 ppb (16) N/A N/A N/A 0.25 ppb (3) N/A 3.0 μg/m3 (12) 21.0
 
March 17, 2019, 11 a.m. 28.8 ppb (27) 9.2 ppb (9) N/A 20.0 ppb (19) N/A N/A N/A 0.24 ppb (3) N/A 3.0 μg/m3 (12) 27.0
 
March 17, 2019, 10 a.m. 20.2 ppb (19) 4.1 ppb (4) N/A 16.0 ppb (15) N/A N/A N/A 0.2 ppb (2) N/A 3.0 μg/m3 (12) 19.0
 
March 17, 2019, 9 a.m. 21.5 ppb (20) 4.7 ppb (4) N/A 17.0 ppb (16) N/A N/A N/A 0.21 ppb (2) N/A 2.0 μg/m3 (8) 20.0
 
March 17, 2019, 8 a.m. N/A N/A N/A N/A N/A N/A N/A 0.22 ppb (2) N/A 3.0 μg/m3 (12) 12.0
 
March 17, 2019, 7 a.m. 10.6 ppb (10) 0.8 ppb (1) N/A 10.0 ppb (9) N/A N/A N/A 0.2 ppb (2) N/A 4.0 μg/m3 (17) 17.0
 
March 17, 2019, 6 a.m. 13.7 ppb (13) 1.9 ppb (2) N/A 12.0 ppb (11) N/A N/A N/A 0.2 ppb (2) N/A 3.0 μg/m3 (12) 13.0
 
March 17, 2019, 5 a.m. 8.9 ppb (8) 1.9 ppb (2) N/A 7.0 ppb (6) N/A N/A N/A 0.17 ppb (2) N/A 3.0 μg/m3 (12) 12.0
 
March 17, 2019, 4 a.m. 3.8 ppb (4) 0.5 ppb (0) N/A 3.0 ppb (3) N/A N/A N/A 0.15 ppb (2) N/A 3.0 μg/m3 (12) 12.0
 
March 17, 2019, 3 a.m. 3.3 ppb (3) 0.3 ppb (0) N/A 3.0 ppb (3) N/A N/A N/A 0.24 ppb (3) N/A 2.0 μg/m3 (8) 8.0
 
March 17, 2019, 2 a.m. 3.7 ppb (3) 0.3 ppb (0) N/A 3.0 ppb (3) N/A N/A N/A 0.24 ppb (3) N/A 3.0 μg/m3 (12) 12.0
 
March 17, 2019, 1 a.m. 4.5 ppb (4) 0.5 ppb (0) N/A 4.0 ppb (4) N/A N/A N/A 0.23 ppb (3) N/A 3.0 μg/m3 (12) 12.0
 
March 17, 2019, midnight 5.7 ppb (5) 0.7 ppb (1) N/A 5.0 ppb (5) N/A N/A N/A 0.23 ppb (3) N/A 2.0 μg/m3 (8) 8.0
 
March 16, 2019, 11 p.m. 5.1 ppb (5) 0.5 ppb (0) N/A 5.0 ppb (5) N/A N/A N/A 0.23 ppb (3) N/A 2.0 μg/m3 (8) 8.0
 
March 16, 2019, 10 p.m. 5.0 ppb (5) 0.6 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.24 ppb (3) N/A 2.0 μg/m3 (8) 8.0
 
March 16, 2019, 9 p.m. 4.8 ppb (4) 0.7 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.23 ppb (3) N/A 3.0 μg/m3 (12) 12.0
 
March 16, 2019, 8 p.m. 4.5 ppb (4) 0.6 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.22 ppb (2) N/A 3.0 μg/m3 (12) 12.0
 
March 16, 2019, 7 p.m. 4.7 ppb (4) 0.7 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.21 ppb (2) N/A 2.0 μg/m3 (8) 8.0
 
March 16, 2019, 6 p.m. 4.7 ppb (4) 0.8 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.21 ppb (2) N/A 1.0 μg/m3 (4) 4.0
 
March 16, 2019, 5 p.m. 5.2 ppb (5) 1.1 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.22 ppb (2) N/A -1.0 μg/m3 (0) 5.0
 
March 16, 2019, 4 p.m. 4.8 ppb (4) 0.9 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.2 ppb (2) N/A 0.0 μg/m3 (0) 4.0
 
March 16, 2019, 3 p.m. 5.2 ppb (5) 0.9 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A 0.19 ppb (2) N/A 1.0 μg/m3 (4) 5.0
 
March 16, 2019, 2 p.m. 6.9 ppb (6) 1.4 ppb (1) N/A 5.0 ppb (5) N/A N/A N/A 0.19 ppb (2) N/A -2.0 μg/m3 (0) 6.0
 
March 16, 2019, 1 p.m. 8.1 ppb (8) 2.1 ppb (2) N/A 6.0 ppb (6) N/A N/A N/A 0.19 ppb (2) N/A -2.0 μg/m3 (0) 8.0
 
March 16, 2019, noon 7.7 ppb (7) 1.8 ppb (2) N/A 6.0 ppb (6) N/A N/A N/A 0.17 ppb (2) N/A 0.0 μg/m3 (0) 7.0
 
March 16, 2019, 11 a.m. 6.7 ppb (6) 1.3 ppb (1) N/A 5.0 ppb (5) N/A N/A N/A 0.17 ppb (2) N/A 1.0 μg/m3 (4) 6.0
 
March 16, 2019, 10 a.m. 6.4 ppb (6) 1.1 ppb (1) N/A 5.0 ppb (5) N/A N/A N/A 0.16 ppb (2) N/A 2.0 μg/m3 (8) 8.0
 
March 16, 2019, 9 a.m. 6.9 ppb (6) 1.3 ppb (1) N/A 6.0 ppb (6) N/A N/A N/A 0.17 ppb (2) N/A 2.0 μg/m3 (8) 8.0
 
March 16, 2019, 8 a.m. 6.0 ppb (6) 0.7 ppb (1) N/A 5.0 ppb (5) N/A N/A N/A 0.15 ppb (2) N/A 0.0 μg/m3 (0) 6.0
 
March 16, 2019, 7 a.m. 8.2 ppb (8) 1.2 ppb (1) N/A 7.0 ppb (6) N/A N/A N/A 0.16 ppb (2) N/A 0.0 μg/m3 (0) 8.0
 
March 16, 2019, 6 a.m. 9.6 ppb (9) 1.5 ppb (1) N/A 8.0 ppb (7) N/A N/A N/A 0.17 ppb (2) N/A 0.0 μg/m3 (0) 9.0
 
March 16, 2019, 5 a.m. 11.0 ppb (10) 1.8 ppb (2) N/A 9.0 ppb (8) N/A N/A N/A 0.18 ppb (2) N/A 2.0 μg/m3 (8) 10.0
 
March 16, 2019, 4 a.m. 10.8 ppb (10) 1.5 ppb (1) N/A 9.0 ppb (8) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 10.0
 
March 16, 2019, 3 a.m. 11.6 ppb (11) 1.4 ppb (1) N/A 10.0 ppb (9) N/A N/A N/A 0.16 ppb (2) N/A 2.0 μg/m3 (8) 11.0
 
March 16, 2019, 2 a.m. 13.9 ppb (13) 1.9 ppb (2) N/A 12.0 ppb (11) N/A N/A N/A 0.18 ppb (2) N/A 4.0 μg/m3 (17) 17.0
 
March 16, 2019, 1 a.m. 17.2 ppb (16) 3.0 ppb (3) N/A 14.0 ppb (13) N/A N/A N/A 0.21 ppb (2) N/A 6.0 μg/m3 (25) 25.0
 
March 16, 2019, midnight 31.3 ppb (29) 10.7 ppb (10) N/A 21.0 ppb (19) N/A N/A N/A 0.32 ppb (4) N/A 9.0 μg/m3 (38) 38.0
 
March 15, 2019, 11 p.m. 33.6 ppb (31) 11.7 ppb (11) N/A 22.0 ppb (20) N/A N/A N/A 0.34 ppb (4) N/A 8.0 μg/m3 (33) 33.0
 
March 15, 2019, 10 p.m. 31.3 ppb (29) 11.2 ppb (10) N/A 20.0 ppb (19) N/A N/A N/A 0.32 ppb (4) N/A 8.0 μg/m3 (33) 33.0
 
March 15, 2019, 9 p.m. 25.0 ppb (23) 7.9 ppb (7) N/A 17.0 ppb (16) N/A N/A N/A 0.29 ppb (3) N/A 10.0 μg/m3 (42) 42.0
 
March 15, 2019, 8 p.m. 24.9 ppb (23) 7.8 ppb (7) N/A 17.0 ppb (16) N/A N/A N/A 0.3 ppb (3) N/A 8.0 μg/m3 (33) 33.0
 
March 15, 2019, 7 p.m. 25.0 ppb (23) 7.5 ppb (7) N/A 18.0 ppb (17) N/A N/A N/A 0.3 ppb (3) N/A 5.0 μg/m3 (21) 23.0
 
March 15, 2019, 6 p.m. N/A N/A N/A N/A N/A N/A N/A 0.29 ppb (3) N/A 9.0 μg/m3 (38) 38.0
 
March 15, 2019, 5 p.m. N/A N/A N/A N/A N/A N/A N/A 0.28 ppb (3) N/A 10.0 μg/m3 (42) 42.0
 
March 15, 2019, 4 p.m. N/A N/A N/A N/A N/A N/A N/A 0.27 ppb (3) N/A 7.0 μg/m3 (29) 29.0
 
March 15, 2019, 3 p.m. N/A N/A N/A N/A N/A N/A N/A 0.33 ppb (4) N/A 7.0 μg/m3 (29) 29.0
 
March 15, 2019, 2 p.m. N/A N/A N/A N/A N/A N/A N/A 0.33 ppb (4) N/A 7.0 μg/m3 (29) 29.0
 
March 15, 2019, 1 p.m. 39.4 ppb (36) 14.4 ppb (13) N/A 25.0 ppb (23) N/A N/A N/A 0.32 ppb (4) N/A 6.0 μg/m3 (25) 36.0
 
March 15, 2019, noon 39.0 ppb (36) 13.7 ppb (13) N/A 25.0 ppb (23) N/A N/A N/A 0.34 ppb (4) N/A 9.0 μg/m3 (38) 38.0
 
March 15, 2019, 11 a.m. 40.7 ppb (38) 13.7 ppb (13) N/A 27.0 ppb (25) N/A N/A N/A 0.33 ppb (4) N/A 10.0 μg/m3 (42) 42.0
 
March 15, 2019, 10 a.m. 40.7 ppb (38) 13.7 ppb (13) N/A 27.0 ppb (25) N/A N/A N/A 0.32 ppb (4) N/A 10.0 μg/m3 (42) 42.0
 
March 15, 2019, 9 a.m. 35.9 ppb (33) 11.9 ppb (11) N/A 24.0 ppb (22) N/A N/A N/A 0.31 ppb (3) N/A 9.0 μg/m3 (38) 38.0
 
March 15, 2019, 8 a.m. N/A N/A N/A N/A N/A N/A N/A 0.25 ppb (3) N/A 6.0 μg/m3 (25) 25.0
 
March 15, 2019, 7 a.m. 29.7 ppb (28) 8.0 ppb (7) N/A 22.0 ppb (20) N/A N/A N/A 0.22 ppb (2) N/A 6.0 μg/m3 (25) 28.0
 
March 15, 2019, 6 a.m. 36.2 ppb (34) 12.3 ppb (11) N/A 24.0 ppb (22) N/A N/A N/A 0.25 ppb (3) N/A 4.0 μg/m3 (17) 34.0
 
March 15, 2019, 5 a.m. 40.9 ppb (38) 13.7 ppb (13) N/A 27.0 ppb (25) N/A N/A N/A 0.26 ppb (3) N/A 6.0 μg/m3 (25) 38.0
 
March 15, 2019, 4 a.m. 39.6 ppb (37) 11.8 ppb (11) N/A 28.0 ppb (26) N/A N/A N/A N/A N/A 9.0 μg/m3 (38) 38.0
 
March 15, 2019, 3 a.m. 36.2 ppb (34) 10.8 ppb (10) N/A 25.0 ppb (23) N/A N/A N/A 0.29 ppb (3) N/A 7.0 μg/m3 (29) 34.0
 
March 15, 2019, 2 a.m. 38.5 ppb (36) 12.8 ppb (12) N/A 26.0 ppb (24) N/A N/A N/A 0.32 ppb (4) N/A 9.0 μg/m3 (38) 38.0
 
March 15, 2019, 1 a.m. 38.7 ppb (36) 11.6 ppb (11) N/A 27.0 ppb (25) N/A N/A N/A 0.33 ppb (4) N/A 7.0 μg/m3 (29) 36.0
 
March 15, 2019, midnight 37.0 ppb (34) 10.9 ppb (10) N/A 26.0 ppb (24) N/A N/A N/A 0.33 ppb (4) N/A 6.0 μg/m3 (25) 34.0
 
March 14, 2019, 11 p.m. 35.0 ppb (32) 9.4 ppb (9) N/A 26.0 ppb (24) N/A N/A N/A 0.34 ppb (4) N/A 4.0 μg/m3 (17) 32.0
 
March 14, 2019, 10 p.m. 33.6 ppb (31) 9.3 ppb (9) N/A 24.0 ppb (22) N/A N/A N/A 0.34 ppb (4) N/A 5.0 μg/m3 (21) 31.0
 
March 14, 2019, 9 p.m. 30.8 ppb (29) 7.9 ppb (7) N/A 23.0 ppb (21) N/A N/A N/A 0.33 ppb (4) N/A 5.0 μg/m3 (21) 29.0
 
March 14, 2019, 8 p.m. 31.4 ppb (29) 8.2 ppb (8) N/A 23.0 ppb (21) N/A N/A N/A 0.34 ppb (4) N/A 5.0 μg/m3 (21) 29.0
 
March 14, 2019, 7 p.m. 33.2 ppb (31) 8.3 ppb (8) N/A 25.0 ppb (23) N/A N/A N/A 0.35 ppb (4) N/A 5.0 μg/m3 (21) 31.0
 
March 14, 2019, 6 p.m. 34.4 ppb (32) 10.9 ppb (10) N/A 23.0 ppb (21) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 32.0
 
March 14, 2019, 5 p.m. 37.0 ppb (34) 11.4 ppb (11) N/A 26.0 ppb (24) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 34.0
 
March 14, 2019, 4 p.m. 45.3 ppb (42) 17.0 ppb (16) N/A 28.0 ppb (26) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 42.0
 
March 14, 2019, 3 p.m. 64.4 ppb (61) 36.0 ppb (33) N/A 28.0 ppb (26) N/A N/A N/A 0.43 ppb (5) N/A 7.0 μg/m3 (29) 61.0
 
March 14, 2019, 2 p.m. 81.1 ppb (79) 48.9 ppb (45) N/A 32.0 ppb (30) N/A N/A N/A 0.48 ppb (5) N/A 10.0 μg/m3 (42) 79.0
 
March 14, 2019, 1 p.m. 93.8 ppb (92) 58.4 ppb (55) N/A 35.0 ppb (32) N/A N/A N/A 0.51 ppb (6) N/A 12.0 μg/m3 (50) 92.0
 
March 14, 2019, noon 104.1 ppb (101) 65.0 ppb (62) N/A 39.0 ppb (36) N/A N/A N/A 0.54 ppb (6) N/A 15.0 μg/m3 (56) 101.0
 
March 14, 2019, 11 a.m. 101.0 ppb (100) 59.8 ppb (56) N/A 41.0 ppb (38) N/A N/A N/A 0.52 ppb (6) N/A 11.0 μg/m3 (46) 100.0
 
March 14, 2019, 10 a.m. 83.6 ppb (81) 44.4 ppb (41) N/A 39.0 ppb (36) N/A N/A N/A 0.44 ppb (5) N/A 7.0 μg/m3 (29) 81.0
 
March 14, 2019, 9 a.m. 70.7 ppb (68) 32.3 ppb (30) N/A 38.0 ppb (35) N/A N/A N/A 0.37 ppb (4) N/A 6.0 μg/m3 (25) 68.0
 
March 14, 2019, 8 a.m. 65.7 ppb (62) 26.6 ppb (25) N/A 39.0 ppb (36) N/A N/A N/A 0.26 ppb (3) N/A 7.0 μg/m3 (29) 62.0
 
March 14, 2019, 7 a.m. 53.3 ppb (49) 17.0 ppb (16) N/A 36.0 ppb (33) N/A N/A N/A 0.22 ppb (2) N/A 8.0 μg/m3 (33) 49.0
 
March 14, 2019, 6 a.m. 47.3 ppb (44) 13.6 ppb (13) N/A 34.0 ppb (31) N/A N/A N/A 0.23 ppb (3) N/A 5.0 μg/m3 (21) 44.0
 
March 14, 2019, 5 a.m. 42.3 ppb (39) 12.0 ppb (11) N/A 30.0 ppb (28) N/A N/A N/A 0.22 ppb (2) N/A 4.0 μg/m3 (17) 39.0
 
March 14, 2019, 4 a.m. 38.4 ppb (36) 10.8 ppb (10) N/A 28.0 ppb (26) N/A N/A N/A 0.23 ppb (3) N/A 5.0 μg/m3 (21) 36.0
 
March 14, 2019, 3 a.m. 39.1 ppb (36) 10.5 ppb (10) N/A 29.0 ppb (27) N/A N/A N/A 0.27 ppb (3) N/A 7.0 μg/m3 (29) 36.0
 
March 14, 2019, 2 a.m. 36.2 ppb (34) 9.4 ppb (9) N/A 27.0 ppb (25) N/A N/A N/A 0.29 ppb (3) N/A 6.0 μg/m3 (25) 34.0
 
March 14, 2019, 1 a.m. 39.2 ppb (36) 11.3 ppb (10) N/A 28.0 ppb (26) N/A N/A N/A 0.3 ppb (3) N/A 6.0 μg/m3 (25) 36.0
 
March 14, 2019, midnight 36.2 ppb (34) 9.3 ppb (9) N/A 27.0 ppb (25) N/A N/A N/A 0.3 ppb (3) N/A 8.0 μg/m3 (33) 34.0