AQSQID: 245100040

Site Name: Oldtown

Location: Baltimore, MD

Reporting: True, Located: True

Current AQI: 20.0

Baltimore MD, US: 39.2981, -76.604698

Date Observed (UTC) NOX NO NOY NO2 NO2Y SO2 OZONE CO PM10 PM2.5 AQI AQI/500
March 24, 2019, 2 p.m. 21.4 ppb (20) 7.7 ppb (7) N/A 14.0 ppb (13) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 20.0
 
March 24, 2019, 1 p.m. 30.5 ppb (28) 10.6 ppb (10) N/A 20.0 ppb (19) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 28.0
 
March 24, 2019, noon 48.3 ppb (45) 19.1 ppb (18) N/A 29.0 ppb (27) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 45.0
 
March 24, 2019, 11 a.m. 58.5 ppb (55) 21.0 ppb (19) N/A 38.0 ppb (35) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 55.0
 
March 24, 2019, 10 a.m. 46.3 ppb (43) 9.2 ppb (9) N/A 37.0 ppb (34) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 43.0
 
March 24, 2019, 9 a.m. 37.8 ppb (35) 5.0 ppb (5) N/A 33.0 ppb (31) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 35.0
 
March 24, 2019, 8 a.m. 31.3 ppb (29) 3.0 ppb (3) N/A 28.0 ppb (26) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 29.0
 
March 24, 2019, 7 a.m. 20.9 ppb (19) 0.9 ppb (1) N/A 20.0 ppb (19) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 19.0
 
March 24, 2019, 6 a.m. 27.6 ppb (26) 4.6 ppb (4) N/A 23.0 ppb (21) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 26.0
 
March 24, 2019, 5 a.m. 14.2 ppb (13) 0.5 ppb (0) N/A 14.0 ppb (13) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 13.0
 
March 24, 2019, 4 a.m. 10.1 ppb (9) 0.4 ppb (0) N/A 10.0 ppb (9) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 9.0
 
March 24, 2019, 3 a.m. 12.4 ppb (11) 0.7 ppb (1) N/A 12.0 ppb (11) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 24, 2019, 2 a.m. 13.0 ppb (12) 0.9 ppb (1) N/A 12.0 ppb (11) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 24, 2019, 1 a.m. 9.7 ppb (9) 0.5 ppb (0) N/A 9.0 ppb (8) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 24, 2019, midnight 7.4 ppb (7) 0.5 ppb (0) N/A 7.0 ppb (6) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 7.0
 
March 23, 2019, 11 p.m. 4.7 ppb (4) 0.5 ppb (0) N/A 4.0 ppb (4) N/A N/A N/A N/A N/A -1.0 μg/m3 (0) 4.0
 
March 23, 2019, 10 p.m. 3.3 ppb (3) 0.6 ppb (1) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 4.0
 
March 23, 2019, 9 p.m. 3.1 ppb (3) 1.0 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 23, 2019, 8 p.m. 3.6 ppb (3) 1.3 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 3.0
 
March 23, 2019, 7 p.m. 3.5 ppb (3) 1.5 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 3.0
 
March 23, 2019, 6 p.m. 2.7 ppb (3) 1.1 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 3.0
 
March 23, 2019, 5 p.m. 2.4 ppb (2) 1.1 ppb (1) N/A 1.0 ppb (1) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 4.0
 
March 23, 2019, 4 p.m. 3.1 ppb (3) 1.4 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 4.0
 
March 23, 2019, 3 p.m. 2.9 ppb (3) 1.3 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 4.0
 
March 23, 2019, 2 p.m. 3.4 ppb (3) 1.5 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 8.0
 
March 23, 2019, 1 p.m. 4.3 ppb (4) 1.8 ppb (2) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 4.0
 
March 23, 2019, noon 4.6 ppb (4) 1.4 ppb (1) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 4.0
 
March 23, 2019, 11 a.m. 5.7 ppb (5) 0.8 ppb (1) N/A 5.0 ppb (5) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 5.0
 
March 23, 2019, 10 a.m. 3.7 ppb (3) 0.5 ppb (0) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 8.0
 
March 23, 2019, 9 a.m. 1.9 ppb (2) 0.1 ppb (0) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 8.0
 
March 23, 2019, 8 a.m. 2.2 ppb (2) 0.0 ppb (0) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 4.0
 
March 23, 2019, 7 a.m. 1.9 ppb (2) 0.0 ppb (0) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 2.0
 
March 23, 2019, 6 a.m. 2.3 ppb (2) 0.2 ppb (0) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A -1.0 μg/m3 (0) 2.0
 
March 23, 2019, 5 a.m. 2.9 ppb (3) 0.1 ppb (0) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 3.0
 
March 23, 2019, 4 a.m. 2.1 ppb (2) 0.2 ppb (0) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A -1.0 μg/m3 (0) 2.0
 
March 23, 2019, 3 a.m. 3.3 ppb (3) 0.3 ppb (0) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 4.0
 
March 23, 2019, 2 a.m. 3.7 ppb (3) 0.4 ppb (0) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 23, 2019, 1 a.m. 3.8 ppb (4) 0.6 ppb (1) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 4.0
 
March 23, 2019, midnight 3.4 ppb (3) 0.3 ppb (0) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 8.0
 
March 22, 2019, 11 p.m. 6.0 ppb (6) 0.8 ppb (1) N/A 5.0 ppb (5) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 22, 2019, 10 p.m. 5.4 ppb (5) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 5.0
 
March 22, 2019, 9 p.m. 6.4 ppb (6) 1.2 ppb (1) N/A 5.0 ppb (5) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 6.0
 
March 22, 2019, 8 p.m. 7.7 ppb (7) 2.2 ppb (2) N/A 5.0 ppb (5) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 7.0
 
March 22, 2019, 7 p.m. 7.0 ppb (6) 2.1 ppb (2) N/A 5.0 ppb (5) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 22, 2019, 6 p.m. 5.4 ppb (5) 1.9 ppb (2) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 29.0
 
March 22, 2019, 5 p.m. 5.8 ppb (5) 1.9 ppb (2) N/A 4.0 ppb (4) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
March 22, 2019, 4 p.m. 5.5 ppb (5) 1.8 ppb (2) N/A 4.0 ppb (4) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 22, 2019, 3 p.m. 5.0 ppb (5) 1.9 ppb (2) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 22, 2019, 2 p.m. 4.9 ppb (5) 1.3 ppb (1) N/A 4.0 ppb (4) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 22, 2019, 1 p.m. 6.3 ppb (6) 1.7 ppb (2) N/A 5.0 ppb (5) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 22, 2019, noon 8.4 ppb (8) 1.9 ppb (2) N/A 6.0 ppb (6) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
March 22, 2019, 11 a.m. 7.6 ppb (7) 1.1 ppb (1) N/A 6.0 ppb (6) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 29.0
 
March 22, 2019, 10 a.m. 5.3 ppb (5) 0.6 ppb (1) N/A 5.0 ppb (5) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 5.0
 
March 22, 2019, 9 a.m. 3.9 ppb (4) 0.3 ppb (0) N/A 4.0 ppb (4) N/A N/A N/A N/A N/A -3.0 μg/m3 (0) 4.0
 
March 22, 2019, 7 a.m. 3.1 ppb (3) 0.0 ppb (0) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A -2.0 μg/m3 (0) 3.0
 
March 22, 2019, 6 a.m. 4.4 ppb (4) 0.1 ppb (0) N/A 4.0 ppb (4) N/A N/A N/A N/A N/A -4.0 μg/m3 (0) 4.0
 
March 22, 2019, 5 a.m. 6.1 ppb (6) 0.1 ppb (0) N/A 6.0 ppb (6) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 6.0
 
March 22, 2019, 4 a.m. 7.5 ppb (7) 0.2 ppb (0) N/A 7.0 ppb (6) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 7.0
 
March 22, 2019, 3 a.m. 7.4 ppb (7) 0.4 ppb (0) N/A 7.0 ppb (6) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 8.0
 
March 22, 2019, 2 a.m. 8.7 ppb (8) 0.4 ppb (0) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 8.0
 
March 22, 2019, 1 a.m. 12.5 ppb (12) 1.0 ppb (1) N/A 12.0 ppb (11) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 22, 2019, midnight 20.1 ppb (19) 1.9 ppb (2) N/A 18.0 ppb (17) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 19.0
 
March 21, 2019, 11 p.m. 11.7 ppb (11) 2.2 ppb (2) N/A 9.0 ppb (8) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 21, 2019, 10 p.m. 13.0 ppb (12) 4.5 ppb (4) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 12.0
 
March 21, 2019, 9 p.m. 16.8 ppb (16) 6.2 ppb (6) N/A 11.0 ppb (10) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 16.0
 
March 21, 2019, 8 p.m. 17.2 ppb (16) 5.8 ppb (5) N/A 11.0 ppb (10) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 16.0
 
March 21, 2019, 7 p.m. 24.0 ppb (22) 8.9 ppb (8) N/A 15.0 ppb (14) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 22.0
 
March 21, 2019, 6 p.m. 20.0 ppb (19) 6.9 ppb (6) N/A 13.0 ppb (12) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 19.0
 
March 21, 2019, 5 p.m. 16.3 ppb (15) 5.1 ppb (5) N/A 11.0 ppb (10) N/A N/A N/A N/A N/A -2.0 μg/m3 (0) 15.0
 
March 21, 2019, 4 p.m. 19.8 ppb (18) 5.1 ppb (5) N/A 15.0 ppb (14) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 18.0
 
March 21, 2019, 3 p.m. 21.3 ppb (20) 4.4 ppb (4) N/A 17.0 ppb (16) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 20.0
 
March 21, 2019, 2 p.m. 24.5 ppb (23) 5.6 ppb (5) N/A 19.0 ppb (18) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 23.0
 
March 21, 2019, 1 p.m. 24.0 ppb (22) 5.6 ppb (5) N/A 18.0 ppb (17) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 22.0
 
March 21, 2019, noon 28.6 ppb (26) 8.1 ppb (8) N/A 20.0 ppb (19) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 26.0
 
March 21, 2019, 11 a.m. 23.9 ppb (22) 6.5 ppb (6) N/A 17.0 ppb (16) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 22.0
 
March 21, 2019, 10 a.m. 20.0 ppb (19) 4.6 ppb (4) N/A 15.0 ppb (14) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 19.0
 
March 21, 2019, 9 a.m. 11.8 ppb (11) 1.5 ppb (1) N/A 10.0 ppb (9) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 21, 2019, 8 a.m. 10.3 ppb (10) 1.0 ppb (1) N/A 9.0 ppb (8) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 21, 2019, 7 a.m. 9.9 ppb (9) 1.2 ppb (1) N/A 9.0 ppb (8) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 21, 2019, 6 a.m. 9.0 ppb (8) 0.9 ppb (1) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 21, 2019, 5 a.m. 8.1 ppb (8) 1.0 ppb (1) N/A 7.0 ppb (6) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 21, 2019, 4 a.m. 7.3 ppb (7) 0.8 ppb (1) N/A 6.0 ppb (6) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 21, 2019, 3 a.m. 7.4 ppb (7) 1.3 ppb (1) N/A 6.0 ppb (6) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
March 21, 2019, 2 a.m. 9.0 ppb (8) 1.4 ppb (1) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 21, 2019, 1 a.m. 8.0 ppb (7) 1.1 ppb (1) N/A 7.0 ppb (6) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 21, 2019, midnight 8.7 ppb (8) 1.7 ppb (2) N/A 7.0 ppb (6) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 29.0
 
March 20, 2019, 11 p.m. 11.1 ppb (10) 1.9 ppb (2) N/A 9.0 ppb (8) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 20, 2019, 10 p.m. 18.7 ppb (17) 3.6 ppb (3) N/A 15.0 ppb (14) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 20, 2019, 9 p.m. 14.7 ppb (14) 3.8 ppb (4) N/A 11.0 ppb (10) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
March 20, 2019, 8 p.m. 14.0 ppb (13) 3.9 ppb (4) N/A 10.0 ppb (9) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 20, 2019, 7 p.m. 13.9 ppb (13) 4.9 ppb (5) N/A 9.0 ppb (8) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 20, 2019, 6 p.m. 16.7 ppb (15) 5.5 ppb (5) N/A 11.0 ppb (10) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 29.0
 
March 20, 2019, 5 p.m. 15.0 ppb (14) 4.5 ppb (4) N/A 11.0 ppb (10) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 20, 2019, 4 p.m. 21.0 ppb (19) 6.8 ppb (6) N/A 14.0 ppb (13) N/A N/A N/A N/A N/A 10.0 μg/m3 (42) 42.0
 
March 20, 2019, 3 p.m. 38.8 ppb (36) 12.8 ppb (12) N/A 26.0 ppb (24) N/A N/A N/A N/A N/A 13.0 μg/m3 (52) 52.0
 
March 20, 2019, 2 p.m. 44.2 ppb (41) 16.7 ppb (15) N/A 28.0 ppb (26) N/A N/A N/A N/A N/A 10.0 μg/m3 (42) 42.0
 
March 20, 2019, 1 p.m. 80.8 ppb (79) 38.7 ppb (36) N/A 42.0 ppb (39) N/A N/A N/A N/A N/A N/A 79.0
 
March 20, 2019, noon 126.8 ppb (105) 80.9 ppb (79) N/A 46.0 ppb (43) N/A N/A N/A N/A N/A 16.0 μg/m3 (59) 105.0
 
March 20, 2019, 11 a.m. 126.9 ppb (105) 83.6 ppb (81) N/A 43.0 ppb (40) N/A N/A N/A N/A N/A 13.0 μg/m3 (52) 105.0
 
March 20, 2019, 10 a.m. 100.4 ppb (99) 57.6 ppb (54) N/A 43.0 ppb (40) N/A N/A N/A N/A N/A 14.0 μg/m3 (54) 99.0
 
March 20, 2019, 9 a.m. 91.5 ppb (90) 52.0 ppb (48) N/A 40.0 ppb (37) N/A N/A N/A N/A N/A 9.0 μg/m3 (38) 90.0
 
March 20, 2019, 8 a.m. 61.8 ppb (58) 22.1 ppb (20) N/A 40.0 ppb (37) N/A N/A N/A N/A N/A 10.0 μg/m3 (42) 58.0
 
March 20, 2019, 7 a.m. 25.9 ppb (24) 0.9 ppb (1) N/A 25.0 ppb (23) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 20, 2019, 6 a.m. 39.2 ppb (36) 5.7 ppb (5) N/A 34.0 ppb (31) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 36.0
 
March 20, 2019, 5 a.m. 48.8 ppb (45) 8.1 ppb (8) N/A 41.0 ppb (38) N/A N/A N/A N/A N/A 8.0 μg/m3 (33) 45.0
 
March 20, 2019, 4 a.m. 32.2 ppb (30) 4.1 ppb (4) N/A 28.0 ppb (26) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 30.0
 
March 20, 2019, 3 a.m. 31.5 ppb (29) 3.5 ppb (3) N/A 28.0 ppb (26) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 29.0
 
March 20, 2019, 2 a.m. 31.4 ppb (29) 5.1 ppb (5) N/A 26.0 ppb (24) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 29.0
 
March 20, 2019, 1 a.m. 31.5 ppb (29) 4.6 ppb (4) N/A 27.0 ppb (25) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 29.0
 
March 20, 2019, midnight 18.7 ppb (17) 3.4 ppb (3) N/A 15.0 ppb (14) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 19, 2019, 11 p.m. 20.8 ppb (19) 3.3 ppb (3) N/A 18.0 ppb (17) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 19, 2019, 10 p.m. 20.9 ppb (19) 3.6 ppb (3) N/A 17.0 ppb (16) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
March 19, 2019, 9 p.m. 14.3 ppb (13) 4.2 ppb (4) N/A 10.0 ppb (9) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 19, 2019, 8 p.m. 10.7 ppb (10) 4.1 ppb (4) N/A 7.0 ppb (6) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 10.0
 
March 19, 2019, 7 p.m. 12.6 ppb (12) 4.6 ppb (4) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 12.0
 
March 19, 2019, 6 p.m. 13.9 ppb (13) 5.5 ppb (5) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 13.0
 
March 19, 2019, 5 p.m. 13.4 ppb (12) 5.0 ppb (5) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 12.0
 
March 19, 2019, 4 p.m. 12.3 ppb (11) 4.8 ppb (4) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 11.0
 
March 19, 2019, 3 p.m. 9.3 ppb (9) 4.0 ppb (4) N/A 5.0 ppb (5) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 9.0
 
March 19, 2019, 2 p.m. 12.7 ppb (12) 5.0 ppb (5) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 12.0
 
March 19, 2019, 1 p.m. N/A N/A N/A N/A N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 19, 2019, noon 44.0 ppb (41) 15.9 ppb (15) N/A 28.0 ppb (26) N/A N/A N/A N/A N/A 11.0 μg/m3 (46) 46.0
 
March 19, 2019, 11 a.m. 53.8 ppb (50) 15.7 ppb (15) N/A 38.0 ppb (35) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 50.0
 
March 19, 2019, 10 a.m. 36.6 ppb (34) 4.4 ppb (4) N/A 32.0 ppb (30) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 34.0
 
March 19, 2019, 9 a.m. 45.7 ppb (42) 7.6 ppb (7) N/A 38.0 ppb (35) N/A N/A N/A N/A N/A 8.0 μg/m3 (33) 42.0
 
March 19, 2019, 8 a.m. 34.2 ppb (32) 2.7 ppb (3) N/A 32.0 ppb (30) N/A N/A N/A N/A N/A 7.0 μg/m3 (29) 32.0
 
March 19, 2019, 7 a.m. 28.5 ppb (26) 1.3 ppb (1) N/A 27.0 ppb (25) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 26.0
 
March 19, 2019, 6 a.m. 24.8 ppb (23) 0.7 ppb (1) N/A 24.0 ppb (22) N/A N/A N/A N/A N/A 8.0 μg/m3 (33) 33.0
 
March 19, 2019, 5 a.m. 20.2 ppb (19) 0.5 ppb (0) N/A 20.0 ppb (19) N/A N/A N/A N/A N/A 10.0 μg/m3 (42) 42.0
 
March 19, 2019, 4 a.m. 17.5 ppb (16) 0.6 ppb (1) N/A 17.0 ppb (16) N/A N/A N/A N/A N/A 9.0 μg/m3 (38) 38.0
 
March 19, 2019, 3 a.m. 15.3 ppb (14) 0.6 ppb (1) N/A 15.0 ppb (14) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 19, 2019, 2 a.m. 15.2 ppb (14) 1.3 ppb (1) N/A 14.0 ppb (13) N/A N/A N/A N/A N/A 8.0 μg/m3 (33) 33.0
 
March 19, 2019, 1 a.m. 18.5 ppb (17) 3.0 ppb (3) N/A 15.0 ppb (14) N/A N/A N/A N/A N/A 9.0 μg/m3 (38) 38.0
 
March 19, 2019, midnight 17.5 ppb (16) 1.8 ppb (2) N/A 16.0 ppb (15) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 16.0
 
March 18, 2019, 11 p.m. 19.8 ppb (18) 3.1 ppb (3) N/A 17.0 ppb (16) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 18.0
 
March 18, 2019, 10 p.m. 17.9 ppb (17) 3.9 ppb (4) N/A 14.0 ppb (13) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
March 18, 2019, 9 p.m. 17.8 ppb (16) 4.6 ppb (4) N/A 13.0 ppb (12) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 16.0
 
March 18, 2019, 8 p.m. 20.1 ppb (19) 6.5 ppb (6) N/A 14.0 ppb (13) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 19.0
 
March 18, 2019, 7 p.m. 12.9 ppb (12) 4.7 ppb (4) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
March 18, 2019, 6 p.m. 12.1 ppb (11) 4.4 ppb (4) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
March 18, 2019, 5 p.m. 12.6 ppb (12) 5.2 ppb (5) N/A 7.0 ppb (6) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
March 18, 2019, 4 p.m. 10.8 ppb (10) 4.6 ppb (4) N/A 6.0 ppb (6) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 10.0
 
March 18, 2019, 3 p.m. 14.1 ppb (13) 5.7 ppb (5) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 13.0
 
March 18, 2019, 2 p.m. 22.7 ppb (21) 9.8 ppb (9) N/A 13.0 ppb (12) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 21.0
 
March 18, 2019, 1 p.m. 28.1 ppb (26) 11.3 ppb (10) N/A 17.0 ppb (16) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 26.0
 
March 18, 2019, noon 35.8 ppb (33) 15.1 ppb (14) N/A 21.0 ppb (19) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 33.0
 
March 18, 2019, 11 a.m. 39.1 ppb (36) 15.6 ppb (14) N/A 23.0 ppb (21) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 36.0
 
March 18, 2019, 10 a.m. 27.5 ppb (25) 8.2 ppb (8) N/A 19.0 ppb (18) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 25.0
 
March 18, 2019, 9 a.m. 27.2 ppb (25) 3.9 ppb (4) N/A 23.0 ppb (21) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 25.0
 
March 18, 2019, 8 a.m. 19.9 ppb (18) 1.4 ppb (1) N/A 18.0 ppb (17) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
March 18, 2019, 7 a.m. 14.6 ppb (14) 1.2 ppb (1) N/A 13.0 ppb (12) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 14.0
 
March 18, 2019, 6 a.m. 12.4 ppb (11) 1.5 ppb (1) N/A 11.0 ppb (10) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 11.0
 
March 18, 2019, 5 a.m. 8.9 ppb (8) 0.9 ppb (1) N/A 8.0 ppb (7) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 8.0
 
March 18, 2019, 4 a.m. 10.7 ppb (10) 1.3 ppb (1) N/A 9.0 ppb (8) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 18, 2019, 3 a.m. 10.7 ppb (10) 1.9 ppb (2) N/A 9.0 ppb (8) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 18, 2019, 2 a.m. 13.0 ppb (12) 1.8 ppb (2) N/A 11.0 ppb (10) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 18, 2019, 1 a.m. 12.8 ppb (12) 1.1 ppb (1) N/A 12.0 ppb (11) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
March 18, 2019, midnight 10.3 ppb (10) 1.3 ppb (1) N/A 9.0 ppb (8) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
March 17, 2019, 11 p.m. 7.0 ppb (6) 1.0 ppb (1) N/A 6.0 ppb (6) N/A N/A N/A N/A N/A 4.0 μg/m3 (17) 17.0
 
March 17, 2019, 10 p.m. 4.1 ppb (4) 0.9 ppb (1) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 3.0 μg/m3 (12) 12.0
 
March 17, 2019, 9 p.m. 2.9 ppb (3) 1.0 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 8.0
 
March 17, 2019, 8 p.m. 3.6 ppb (3) 1.1 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 8.0
 
March 17, 2019, 7 p.m. 3.5 ppb (3) 1.2 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 2.0 μg/m3 (8) 8.0
 
March 17, 2019, 6 p.m. 2.6 ppb (2) 1.0 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 2.0
 
March 17, 2019, 5 p.m. 2.2 ppb (2) 0.8 ppb (1) N/A 1.0 ppb (1) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 2.0
 
March 17, 2019, 4 p.m. 2.6 ppb (2) 0.9 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 4.0
 
March 17, 2019, 3 p.m. 3.4 ppb (3) 1.1 ppb (1) N/A 2.0 ppb (2) N/A N/A N/A N/A N/A 1.0 μg/m3 (4) 4.0
 
March 17, 2019, 2 p.m. 3.7 ppb (3) 1.1 ppb (1) N/A 3.0 ppb (3) N/A N/A N/A N/A N/A 0.0 μg/m3 (0) 3.0