ID: 7720

AQSQID: 840250170010

Site Name: Chelmsfordnr

Added: April 21, 2020, 6:24 p.m.

Updated: May 11, 2021, 1:48 a.m.

Location: Chelmsford (E Chelmsford), MA

Reporting: True, Located: True

Current AQI: 39.0

Chelmsford (E Chelmsford) MA, US: 42.612113, -71.307519

Date Observed (UTC) NOX NO NOY NO2 NO2Y SO2 OZONE CO PM10 PM2.5 AQI AQI/500
May 10, 2021, 11 p.m. 40.6 ppb (39) 18.3 ppb (18) N/A 22.0 ppb (21) N/A N/A 20.0 ppb (19) N/A N/A 4.0 μg/m3 (17) 39.0
 
May 10, 2021, 10 p.m. 26.3 ppb (25) 9.9 ppb (10) N/A 16.0 ppb (16) N/A N/A 27.0 ppb (25) N/A N/A 5.0 μg/m3 (21) 25.0
 
May 10, 2021, 9 p.m. 30.8 ppb (30) 13.1 ppb (13) N/A 18.0 ppb (17) N/A N/A 28.0 ppb (26) N/A N/A 4.0 μg/m3 (17) 30.0
 
May 10, 2021, 8 p.m. 12.5 ppb (12) 4.9 ppb (5) N/A 8.0 ppb (8) N/A N/A 35.0 ppb (33) N/A N/A 4.0 μg/m3 (17) 33.0
 
May 10, 2021, 7 p.m. 12.9 ppb (13) 5.3 ppb (5) N/A 8.0 ppb (8) N/A N/A 35.0 ppb (33) N/A N/A 4.0 μg/m3 (17) 33.0
 
May 10, 2021, 6 p.m. 7.8 ppb (8) 3.2 ppb (4) N/A 5.0 ppb (5) N/A N/A 37.0 ppb (35) N/A N/A 4.0 μg/m3 (17) 35.0
 
May 10, 2021, 5 p.m. 8.8 ppb (9) 4.0 ppb (4) N/A 5.0 ppb (5) N/A N/A 38.0 ppb (36) N/A N/A 3.0 μg/m3 (13) 36.0
 
May 10, 2021, 4 p.m. 14.9 ppb (15) 6.7 ppb (7) N/A 8.0 ppb (8) N/A N/A 35.0 ppb (33) N/A N/A 4.0 μg/m3 (17) 33.0
 
May 10, 2021, 3 p.m. 10.9 ppb (11) 4.7 ppb (5) N/A 6.0 ppb (6) N/A N/A 34.0 ppb (32) N/A N/A 4.0 μg/m3 (17) 32.0
 
May 10, 2021, 2 p.m. 6.0 ppb (6) 2.0 ppb (2) N/A 4.0 ppb (4) N/A N/A 35.0 ppb (33) N/A N/A 4.0 μg/m3 (17) 33.0
 
May 10, 2021, 1 p.m. 4.0 ppb (4) 1.0 ppb (1) N/A 3.0 ppb (3) N/A N/A 37.0 ppb (35) N/A N/A 4.0 μg/m3 (17) 35.0
 
May 10, 2021, noon 8.0 ppb (8) 1.0 ppb (1) N/A 7.0 ppb (7) N/A N/A 31.0 ppb (29) N/A N/A 5.0 μg/m3 (21) 29.0
 
May 10, 2021, 11 a.m. 8.0 ppb (8) 1.0 ppb (1) N/A 7.0 ppb (7) N/A N/A 28.0 ppb (26) N/A N/A 5.0 μg/m3 (21) 26.0
 
May 10, 2021, 10 a.m. 8.0 ppb (8) 1.0 ppb (1) N/A 7.0 ppb (7) N/A N/A 27.0 ppb (25) N/A N/A 7.0 μg/m3 (30) 30.0
 
May 10, 2021, 9 a.m. 4.0 ppb (4) 0.0 ppb (0) N/A 4.0 ppb (4) N/A N/A 28.0 ppb (26) N/A N/A 6.0 μg/m3 (25) 26.0
 
May 10, 2021, 8 a.m. 10.0 ppb (10) 2.0 ppb (2) N/A 8.0 ppb (8) N/A N/A 25.0 ppb (24) N/A N/A 7.0 μg/m3 (30) 30.0
 
May 10, 2021, 7 a.m. 14.0 ppb (14) 4.0 ppb (4) N/A 10.0 ppb (10) N/A N/A 24.0 ppb (23) N/A N/A 8.0 μg/m3 (34) 34.0
 
May 10, 2021, 6 a.m. 21.0 ppb (20) 6.0 ppb (6) N/A 15.0 ppb (15) N/A N/A 19.0 ppb (18) N/A N/A 9.0 μg/m3 (38) 38.0
 
May 10, 2021, 5 a.m. 18.0 ppb (17) 4.0 ppb (4) N/A 14.0 ppb (14) N/A N/A 25.0 ppb (24) N/A N/A 6.0 μg/m3 (25) 25.0
 
May 10, 2021, 4 a.m. 16.0 ppb (16) 4.0 ppb (4) N/A 12.0 ppb (12) N/A N/A 29.0 ppb (27) N/A N/A 5.0 μg/m3 (21) 27.0
 
May 10, 2021, 3 a.m. 11.0 ppb (11) 3.0 ppb (3) N/A 8.0 ppb (8) N/A N/A 36.0 ppb (34) N/A N/A 5.0 μg/m3 (21) 34.0
 
May 10, 2021, 2 a.m. 7.0 ppb (7) 1.0 ppb (1) N/A 5.0 ppb (5) N/A N/A 40.0 ppb (38) N/A N/A 4.0 μg/m3 (17) 38.0
 
May 10, 2021, 1 a.m. 8.0 ppb (8) 2.0 ppb (2) N/A 6.0 ppb (6) N/A N/A 35.0 ppb (33) N/A N/A 4.0 μg/m3 (17) 33.0
 
May 10, 2021, midnight 11.0 ppb (11) 3.0 ppb (3) N/A 8.0 ppb (8) N/A N/A 33.0 ppb (31) N/A N/A 4.0 μg/m3 (17) 31.0
 
May 9, 2021, 11 p.m. 13.0 ppb (13) 3.0 ppb (3) N/A 10.0 ppb (10) N/A N/A 30.0 ppb (28) N/A N/A 4.0 μg/m3 (17) 28.0
 
May 9, 2021, 10 p.m. 10.0 ppb (10) 3.0 ppb (3) N/A 7.0 ppb (7) N/A N/A 35.0 ppb (33) N/A N/A 4.0 μg/m3 (17) 33.0
 
May 9, 2021, 9 p.m. 9.0 ppb (9) 3.0 ppb (3) N/A 6.0 ppb (6) N/A N/A 37.0 ppb (35) N/A N/A 4.0 μg/m3 (17) 35.0
 
May 9, 2021, 8 p.m. 5.0 ppb (5) 2.0 ppb (2) N/A 3.0 ppb (3) N/A N/A 38.0 ppb (36) N/A N/A 3.0 μg/m3 (13) 36.0
 
May 9, 2021, 7 p.m. 9.0 ppb (9) 4.0 ppb (4) N/A 5.0 ppb (5) N/A N/A 36.0 ppb (34) N/A N/A 3.0 μg/m3 (13) 34.0
 
May 9, 2021, 6 p.m. 6.0 ppb (6) 3.0 ppb (3) N/A 3.0 ppb (3) N/A N/A 37.0 ppb (35) N/A N/A 2.0 μg/m3 (9) 35.0
 
May 9, 2021, 5 p.m. 6.0 ppb (6) 3.0 ppb (3) N/A 4.0 ppb (4) N/A N/A 36.0 ppb (34) N/A N/A 2.0 μg/m3 (9) 34.0
 
May 9, 2021, 4 p.m. 9.0 ppb (9) 4.0 ppb (4) N/A 5.0 ppb (5) N/A N/A 34.0 ppb (32) N/A N/A 2.0 μg/m3 (9) 32.0
 
May 9, 2021, 3 p.m. 7.0 ppb (7) 3.0 ppb (3) N/A 3.0 ppb (3) N/A N/A 34.0 ppb (32) N/A N/A 2.0 μg/m3 (9) 32.0
 
May 9, 2021, 2 p.m. 8.0 ppb (8) 4.0 ppb (4) N/A 4.0 ppb (4) N/A N/A 32.0 ppb (30) N/A N/A 2.0 μg/m3 (9) 30.0
 
May 9, 2021, 1 p.m. 5.0 ppb (5) 2.0 ppb (2) N/A 3.0 ppb (3) N/A N/A 33.0 ppb (31) N/A N/A 2.0 μg/m3 (9) 31.0
 
May 9, 2021, noon 3.0 ppb (3) 1.0 ppb (1) N/A 2.0 ppb (2) N/A N/A 30.0 ppb (28) N/A N/A 2.0 μg/m3 (9) 28.0
 
May 9, 2021, 11 a.m. 4.0 ppb (4) 2.0 ppb (2) N/A 2.0 ppb (2) N/A N/A 29.0 ppb (27) N/A N/A 2.0 μg/m3 (9) 27.0
 
May 9, 2021, 10 a.m. 4.0 ppb (4) 1.0 ppb (1) N/A 3.0 ppb (3) N/A N/A 27.0 ppb (25) N/A N/A 2.0 μg/m3 (9) 25.0
 
May 9, 2021, 9 a.m. 4.0 ppb (4) 1.0 ppb (1) N/A 3.0 ppb (3) N/A N/A 26.0 ppb (25) N/A N/A 2.0 μg/m3 (9) 25.0
 
May 9, 2021, 8 a.m. 6.0 ppb (6) 2.0 ppb (2) N/A 4.0 ppb (4) N/A N/A 27.0 ppb (25) N/A N/A 3.0 μg/m3 (13) 25.0
 
May 9, 2021, 7 a.m. 4.0 ppb (4) 1.0 ppb (1) N/A 3.0 ppb (3) N/A N/A 28.0 ppb (26) N/A N/A 3.0 μg/m3 (13) 26.0
 
May 9, 2021, 6 a.m. 2.0 ppb (2) 1.0 ppb (1) N/A 2.0 ppb (2) N/A N/A 29.0 ppb (27) N/A N/A 3.0 μg/m3 (13) 27.0
 
May 9, 2021, 5 a.m. 3.0 ppb (3) 1.0 ppb (1) N/A 2.0 ppb (2) N/A N/A 29.0 ppb (27) N/A N/A 3.0 μg/m3 (13) 27.0
 
May 9, 2021, 4 a.m. 11.0 ppb (11) 4.0 ppb (4) N/A 7.0 ppb (7) N/A N/A 25.0 ppb (24) N/A N/A 4.0 μg/m3 (17) 24.0
 
May 9, 2021, 3 a.m. 8.0 ppb (8) 2.0 ppb (2) N/A 6.0 ppb (6) N/A N/A 24.0 ppb (23) N/A N/A 5.0 μg/m3 (21) 23.0
 
May 9, 2021, 2 a.m. 15.0 ppb (15) 6.0 ppb (6) N/A 9.0 ppb (9) N/A N/A 23.0 ppb (22) N/A N/A 5.0 μg/m3 (21) 22.0
 
May 9, 2021, 1 a.m. 13.0 ppb (13) 5.0 ppb (5) N/A 8.0 ppb (8) N/A N/A 23.0 ppb (22) N/A N/A 5.0 μg/m3 (21) 22.0
 
May 9, 2021, midnight 16.0 ppb (16) 6.0 ppb (6) N/A 11.0 ppb (11) N/A N/A 20.0 ppb (19) N/A N/A 5.0 μg/m3 (21) 21.0
 
May 8, 2021, 11 p.m. 18.0 ppb (17) 6.0 ppb (6) N/A 11.0 ppb (11) N/A N/A 20.0 ppb (19) N/A N/A 4.0 μg/m3 (17) 19.0
 
May 8, 2021, 10 p.m. 20.0 ppb (19) 9.0 ppb (9) N/A 11.0 ppb (11) N/A N/A 21.0 ppb (20) N/A N/A 4.0 μg/m3 (17) 20.0
 
May 8, 2021, 9 p.m. 16.0 ppb (16) 7.0 ppb (7) N/A 9.0 ppb (9) N/A N/A 24.0 ppb (23) N/A N/A 4.0 μg/m3 (17) 23.0
 
May 8, 2021, 8 p.m. 9.0 ppb (9) 4.0 ppb (4) N/A 5.0 ppb (5) N/A N/A 30.0 ppb (28) N/A N/A 3.0 μg/m3 (13) 28.0
 
May 8, 2021, 7 p.m. 9.0 ppb (9) 4.0 ppb (4) N/A 5.0 ppb (5) N/A N/A 30.0 ppb (28) N/A N/A 3.0 μg/m3 (13) 28.0
 
May 8, 2021, 6 p.m. 8.0 ppb (8) 4.0 ppb (4) N/A 4.0 ppb (4) N/A N/A 31.0 ppb (29) N/A N/A 3.0 μg/m3 (13) 29.0
 
May 8, 2021, 5 p.m. 14.0 ppb (14) 7.0 ppb (7) N/A 6.0 ppb (6) N/A N/A 29.0 ppb (27) N/A N/A 2.0 μg/m3 (9) 27.0
 
May 8, 2021, 4 p.m. 7.0 ppb (7) 3.0 ppb (3) N/A 4.0 ppb (4) N/A N/A 30.0 ppb (28) N/A N/A 2.0 μg/m3 (9) 28.0
 
May 8, 2021, 3 p.m. 4.0 ppb (4) 2.0 ppb (2) N/A 2.0 ppb (2) N/A N/A 29.0 ppb (27) N/A N/A 2.0 μg/m3 (9) 27.0
 
May 8, 2021, 2 p.m. 5.0 ppb (5) 2.0 ppb (2) N/A 3.0 ppb (3) N/A N/A 28.0 ppb (26) N/A N/A 2.0 μg/m3 (9) 26.0
 
May 8, 2021, 1 p.m. 2.0 ppb (2) 1.0 ppb (1) N/A 2.0 ppb (2) N/A N/A 29.0 ppb (27) N/A N/A 2.0 μg/m3 (9) 27.0
 
May 8, 2021, noon 4.0 ppb (4) 1.0 ppb (1) N/A 3.0 ppb (3) N/A N/A 27.0 ppb (25) N/A N/A 3.0 μg/m3 (13) 25.0
 
May 8, 2021, 11 a.m. 13.0 ppb (13) 5.0 ppb (5) N/A 8.0 ppb (8) N/A N/A 18.0 ppb (17) N/A N/A 5.0 μg/m3 (21) 21.0
 
May 8, 2021, 10 a.m. 16.0 ppb (16) 6.0 ppb (6) N/A 10.0 ppb (10) N/A N/A 11.0 ppb (11) N/A N/A 6.0 μg/m3 (25) 25.0
 
May 8, 2021, 9 a.m. 10.0 ppb (10) 1.0 ppb (1) N/A 8.0 ppb (8) N/A N/A 13.0 ppb (13) N/A N/A 5.0 μg/m3 (21) 21.0
 
May 8, 2021, 8 a.m. 7.0 ppb (7) 1.0 ppb (1) N/A 7.0 ppb (7) N/A N/A N/A N/A N/A 5.0 μg/m3 (21) 21.0
 
May 8, 2021, 7 a.m. N/A N/A N/A N/A N/A N/A 15.0 ppb (14) N/A N/A 5.0 μg/m3 (21) 21.0
 
May 8, 2021, 6 a.m. N/A N/A N/A N/A N/A N/A 14.0 ppb (13) N/A N/A 6.0 μg/m3 (25) 25.0
 
May 8, 2021, 5 a.m. N/A N/A N/A N/A N/A N/A 3.0 ppb (3) N/A N/A 9.0 μg/m3 (38) 38.0
 
May 8, 2021, 4 a.m. 36.0 ppb (34) 15.0 ppb (15) N/A 21.0 ppb (20) N/A N/A 6.0 ppb (6) N/A N/A 9.0 μg/m3 (38) 38.0
 
May 8, 2021, 3 a.m. 32.0 ppb (31) 11.0 ppb (11) N/A 21.0 ppb (20) N/A N/A 6.0 ppb (6) N/A N/A 11.0 μg/m3 (46) 46.0
 
May 8, 2021, 2 a.m. 25.0 ppb (24) 10.0 ppb (10) N/A 15.0 ppb (15) N/A N/A 14.0 ppb (13) N/A N/A 7.0 μg/m3 (30) 30.0
 
May 8, 2021, 1 a.m. 19.0 ppb (18) 3.0 ppb (3) N/A 17.0 ppb (17) N/A N/A 15.0 ppb (14) N/A N/A 10.0 μg/m3 (42) 42.0
 
May 8, 2021, midnight 36.0 ppb (34) 14.0 ppb (14) N/A 22.0 ppb (21) N/A N/A 16.0 ppb (15) N/A N/A 8.0 μg/m3 (34) 34.0
 
May 7, 2021, 11 p.m. 27.0 ppb (26) 11.0 ppb (11) N/A 16.0 ppb (16) N/A N/A 24.0 ppb (23) N/A N/A 8.0 μg/m3 (34) 34.0
 
May 7, 2021, 10 p.m. 21.0 ppb (20) 10.0 ppb (10) N/A 11.0 ppb (11) N/A N/A 28.0 ppb (26) N/A N/A 3.0 μg/m3 (13) 26.0
 
May 7, 2021, 9 p.m. 23.0 ppb (22) 11.0 ppb (11) N/A 11.0 ppb (11) N/A N/A 29.0 ppb (27) N/A N/A 3.0 μg/m3 (13) 27.0
 
May 7, 2021, 8 p.m. 17.0 ppb (17) 8.0 ppb (8) N/A 9.0 ppb (9) N/A N/A 31.0 ppb (29) N/A N/A 3.0 μg/m3 (13) 29.0
 
May 7, 2021, 7 p.m. 25.0 ppb (24) 14.0 ppb (14) N/A 11.0 ppb (11) N/A N/A 28.0 ppb (26) N/A N/A 3.0 μg/m3 (13) 26.0
 
May 7, 2021, 6 p.m. 22.0 ppb (21) 12.0 ppb (12) N/A 10.0 ppb (10) N/A N/A 30.0 ppb (28) N/A N/A 4.0 μg/m3 (17) 28.0
 
May 7, 2021, 5 p.m. 22.0 ppb (21) 12.0 ppb (12) N/A 10.0 ppb (10) N/A N/A 30.0 ppb (28) N/A N/A 4.0 μg/m3 (17) 28.0
 
May 7, 2021, 4 p.m. 27.0 ppb (26) 15.0 ppb (15) N/A 12.0 ppb (12) N/A N/A 29.0 ppb (27) N/A N/A 4.0 μg/m3 (17) 27.0
 
May 7, 2021, 3 p.m. 26.0 ppb (25) 14.0 ppb (14) N/A 12.0 ppb (12) N/A N/A 29.0 ppb (27) N/A N/A 4.0 μg/m3 (17) 27.0
 
May 7, 2021, 2 p.m. 20.0 ppb (19) 10.0 ppb (10) N/A 10.0 ppb (10) N/A N/A 30.0 ppb (28) N/A N/A 4.0 μg/m3 (17) 28.0
 
May 7, 2021, 1 p.m. 19.0 ppb (18) 9.0 ppb (9) N/A 10.0 ppb (10) N/A N/A 27.0 ppb (25) N/A N/A 4.0 μg/m3 (17) 25.0
 
May 7, 2021, noon 12.0 ppb (12) 4.0 ppb (4) N/A 8.0 ppb (8) N/A N/A 24.0 ppb (23) N/A N/A 4.0 μg/m3 (17) 23.0
 
May 7, 2021, 11 a.m. 14.0 ppb (14) 4.0 ppb (4) N/A 10.0 ppb (10) N/A N/A 20.0 ppb (19) N/A N/A 4.0 μg/m3 (17) 19.0
 
May 7, 2021, 10 a.m. 20.0 ppb (19) 5.0 ppb (5) N/A 15.0 ppb (15) N/A N/A 6.0 ppb (6) N/A N/A 4.0 μg/m3 (17) 19.0
 
May 7, 2021, 9 a.m. 37.0 ppb (35) 18.0 ppb (17) N/A 19.0 ppb (18) N/A N/A 5.0 ppb (5) N/A N/A 4.0 μg/m3 (17) 35.0
 
May 7, 2021, 8 a.m. 66.0 ppb (64) 42.0 ppb (40) N/A 23.0 ppb (22) N/A N/A 1.0 ppb (1) N/A N/A 4.0 μg/m3 (17) 64.0
 
May 7, 2021, 7 a.m. 55.0 ppb (53) 29.0 ppb (28) N/A 27.0 ppb (26) N/A N/A 1.0 ppb (1) N/A N/A 4.0 μg/m3 (17) 53.0
 
May 7, 2021, 6 a.m. 40.0 ppb (38) 17.0 ppb (17) N/A 23.0 ppb (22) N/A N/A 7.0 ppb (7) N/A N/A 4.0 μg/m3 (17) 38.0
 
May 7, 2021, 5 a.m. 43.0 ppb (41) 19.0 ppb (18) N/A 24.0 ppb (23) N/A N/A 8.0 ppb (8) N/A N/A 4.0 μg/m3 (17) 41.0
 
May 7, 2021, 4 a.m. 11.0 ppb (11) 1.0 ppb (1) N/A 10.0 ppb (10) N/A N/A 23.0 ppb (22) N/A N/A 3.0 μg/m3 (13) 22.0
 
May 7, 2021, 3 a.m. 4.0 ppb (4) 0.0 ppb (0) N/A 3.0 ppb (3) N/A N/A 31.0 ppb (29) N/A N/A 3.0 μg/m3 (13) 29.0
 
May 7, 2021, 2 a.m. 4.0 ppb (4) 1.0 ppb (1) N/A 3.0 ppb (3) N/A N/A 32.0 ppb (30) N/A N/A 3.0 μg/m3 (13) 30.0
 
May 7, 2021, 1 a.m. 6.0 ppb (6) 1.0 ppb (1) N/A 5.0 ppb (5) N/A N/A 30.0 ppb (28) N/A N/A 4.0 μg/m3 (17) 28.0
 
May 7, 2021, midnight 5.0 ppb (5) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 34.0 ppb (32) N/A N/A 3.0 μg/m3 (13) 32.0
 
May 6, 2021, 11 p.m. 3.0 ppb (3) 1.0 ppb (1) N/A 2.0 ppb (2) N/A N/A 36.0 ppb (34) N/A N/A 3.0 μg/m3 (13) 34.0
 
May 6, 2021, 10 p.m. 2.0 ppb (2) 1.0 ppb (1) N/A 1.0 ppb (1) N/A N/A 38.0 ppb (36) N/A N/A 2.0 μg/m3 (9) 36.0
 
May 6, 2021, 9 p.m. 5.0 ppb (5) 3.0 ppb (3) N/A 3.0 ppb (3) N/A N/A 38.0 ppb (36) N/A N/A 2.0 μg/m3 (9) 36.0
 
May 6, 2021, 8 p.m. 6.0 ppb (6) 3.0 ppb (3) N/A 3.0 ppb (3) N/A N/A 36.0 ppb (34) N/A N/A 2.0 μg/m3 (9) 34.0
 
May 6, 2021, 7 p.m. 5.0 ppb (5) 3.0 ppb (3) N/A 2.0 ppb (2) N/A N/A 36.0 ppb (34) N/A N/A 2.0 μg/m3 (9) 34.0
 
May 6, 2021, 6 p.m. 9.0 ppb (9) 5.0 ppb (5) N/A 4.0 ppb (4) N/A N/A 34.0 ppb (32) N/A N/A 2.0 μg/m3 (9) 32.0
 
May 6, 2021, 5 p.m. 4.0 ppb (4) 2.0 ppb (2) N/A 2.0 ppb (2) N/A N/A 36.0 ppb (34) N/A N/A 2.0 μg/m3 (9) 34.0
 
May 6, 2021, 4 p.m. 9.0 ppb (9) 5.0 ppb (5) N/A 4.0 ppb (4) N/A N/A 33.0 ppb (31) N/A N/A 2.0 μg/m3 (9) 31.0
 
May 6, 2021, 3 p.m. 4.0 ppb (4) 2.0 ppb (2) N/A 2.0 ppb (2) N/A N/A 34.0 ppb (32) N/A N/A 1.0 μg/m3 (5) 32.0
 
May 6, 2021, 2 p.m. 7.0 ppb (7) 4.0 ppb (4) N/A 3.0 ppb (3) N/A N/A 32.0 ppb (30) N/A N/A 1.0 μg/m3 (5) 30.0
 
May 6, 2021, 1 p.m. 3.0 ppb (3) 2.0 ppb (2) N/A 1.0 ppb (1) N/A N/A 31.0 ppb (29) N/A N/A 1.0 μg/m3 (5) 29.0
 
May 6, 2021, noon 6.0 ppb (6) 3.0 ppb (3) N/A 2.0 ppb (2) N/A N/A 27.0 ppb (25) N/A N/A 2.0 μg/m3 (9) 25.0
 
May 6, 2021, 11 a.m. 9.0 ppb (9) 5.0 ppb (5) N/A 4.0 ppb (4) N/A N/A 22.0 ppb (21) N/A N/A 2.0 μg/m3 (9) 21.0
 
May 6, 2021, 10 a.m. 14.0 ppb (14) 8.0 ppb (8) N/A 6.0 ppb (6) N/A N/A 17.0 ppb (16) N/A N/A 2.0 μg/m3 (9) 16.0
 
May 6, 2021, 9 a.m. 9.0 ppb (9) 4.0 ppb (4) N/A 4.0 ppb (4) N/A N/A 17.0 ppb (16) N/A N/A 2.0 μg/m3 (9) 16.0
 
May 6, 2021, 8 a.m. 4.0 ppb (4) 2.0 ppb (2) N/A 3.0 ppb (3) N/A N/A 18.0 ppb (17) N/A N/A 2.0 μg/m3 (9) 17.0
 
May 6, 2021, 7 a.m. 7.0 ppb (7) 2.0 ppb (2) N/A 5.0 ppb (5) N/A N/A 16.0 ppb (15) N/A N/A 3.0 μg/m3 (13) 15.0
 
May 6, 2021, 6 a.m. 18.0 ppb (17) 5.0 ppb (5) N/A 13.0 ppb (13) N/A N/A 7.0 ppb (7) N/A N/A 5.0 μg/m3 (21) 21.0
 
May 6, 2021, 5 a.m. 39.0 ppb (37) 20.0 ppb (19) N/A 19.0 ppb (18) N/A N/A 6.0 ppb (6) N/A N/A 6.0 μg/m3 (25) 37.0
 
May 6, 2021, 4 a.m. 13.0 ppb (13) 3.0 ppb (3) N/A 10.0 ppb (10) N/A N/A 15.0 ppb (14) N/A N/A 6.0 μg/m3 (25) 25.0
 
May 6, 2021, 3 a.m. 10.0 ppb (10) 2.0 ppb (2) N/A 8.0 ppb (8) N/A N/A 18.0 ppb (17) N/A N/A 5.0 μg/m3 (21) 21.0
 
May 6, 2021, 2 a.m. 6.0 ppb (6) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 22.0 ppb (21) N/A N/A 4.0 μg/m3 (17) 21.0
 
May 6, 2021, 1 a.m. 5.0 ppb (5) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 24.0 ppb (23) N/A N/A 3.0 μg/m3 (13) 23.0
 
May 6, 2021, midnight 6.0 ppb (6) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 25.0 ppb (24) N/A N/A 3.0 μg/m3 (13) 24.0
 
May 5, 2021, 11 p.m. 4.0 ppb (4) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 27.0 ppb (25) N/A N/A 3.0 μg/m3 (13) 25.0
 
May 5, 2021, 10 p.m. 6.0 ppb (6) 1.0 ppb (1) N/A 5.0 ppb (5) N/A N/A 27.0 ppb (25) N/A N/A 3.0 μg/m3 (13) 25.0
 
May 5, 2021, 9 p.m. 5.0 ppb (5) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 28.0 ppb (26) N/A N/A 3.0 μg/m3 (13) 26.0
 
May 5, 2021, 8 p.m. 5.0 ppb (5) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 29.0 ppb (27) N/A N/A 3.0 μg/m3 (13) 27.0
 
May 5, 2021, 7 p.m. 5.0 ppb (5) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 30.0 ppb (28) N/A N/A 4.0 μg/m3 (17) 28.0
 
May 5, 2021, 6 p.m. 6.0 ppb (6) 1.0 ppb (1) N/A 5.0 ppb (5) N/A N/A 28.0 ppb (26) N/A N/A 7.0 μg/m3 (30) 30.0
 
May 5, 2021, 5 p.m. 6.0 ppb (6) 1.0 ppb (1) N/A 5.0 ppb (5) N/A N/A 29.0 ppb (27) N/A N/A 5.0 μg/m3 (21) 27.0
 
May 5, 2021, 4 p.m. 8.0 ppb (8) 2.0 ppb (2) N/A 6.0 ppb (6) N/A N/A 29.0 ppb (27) N/A N/A 3.0 μg/m3 (13) 27.0
 
May 5, 2021, 3 p.m. 33.0 ppb (32) 14.0 ppb (14) N/A 19.0 ppb (18) N/A N/A 19.0 ppb (18) N/A N/A 3.0 μg/m3 (13) 32.0
 
May 5, 2021, 2 p.m. 43.0 ppb (41) 20.0 ppb (19) N/A 23.0 ppb (22) N/A N/A 16.0 ppb (15) N/A N/A 3.0 μg/m3 (13) 41.0
 
May 5, 2021, 1 p.m. 38.0 ppb (36) 17.0 ppb (17) N/A 21.0 ppb (20) N/A N/A 17.0 ppb (16) N/A N/A 4.0 μg/m3 (17) 36.0
 
May 5, 2021, noon 35.0 ppb (34) 12.0 ppb (12) N/A 23.0 ppb (22) N/A N/A 15.0 ppb (14) N/A N/A 5.0 μg/m3 (21) 34.0
 
May 5, 2021, 11 a.m. 45.0 ppb (43) 19.0 ppb (18) N/A 27.0 ppb (26) N/A N/A 13.0 ppb (13) N/A N/A 6.0 μg/m3 (25) 43.0
 
May 5, 2021, 10 a.m. 46.0 ppb (44) 20.0 ppb (19) N/A 26.0 ppb (25) N/A N/A 12.0 ppb (12) N/A N/A 6.0 μg/m3 (25) 44.0
 
May 5, 2021, 9 a.m. 17.0 ppb (17) 7.0 ppb (7) N/A 10.0 ppb (10) N/A N/A 19.0 ppb (18) N/A N/A 5.0 μg/m3 (21) 21.0
 
May 5, 2021, 8 a.m. 17.0 ppb (17) 5.0 ppb (5) N/A 12.0 ppb (12) N/A N/A N/A N/A N/A 6.0 μg/m3 (25) 25.0
 
May 5, 2021, 7 a.m. N/A N/A N/A N/A N/A N/A 14.0 ppb (13) N/A N/A 7.0 μg/m3 (30) 30.0
 
May 5, 2021, 6 a.m. N/A N/A N/A N/A N/A N/A 16.0 ppb (15) N/A N/A 7.0 μg/m3 (30) 30.0
 
May 5, 2021, 5 a.m. N/A N/A N/A N/A N/A N/A 21.0 ppb (20) N/A N/A 5.0 μg/m3 (21) 21.0
 
May 5, 2021, 4 a.m. 35.0 ppb (34) 15.0 ppb (15) N/A 20.0 ppb (19) N/A N/A 20.0 ppb (19) N/A N/A 6.0 μg/m3 (25) 34.0
 
May 5, 2021, 3 a.m. 22.0 ppb (21) 7.0 ppb (7) N/A 16.0 ppb (16) N/A N/A 25.0 ppb (24) N/A N/A 4.0 μg/m3 (17) 24.0
 
May 5, 2021, 2 a.m. 20.0 ppb (19) 6.0 ppb (6) N/A 13.0 ppb (13) N/A N/A 27.0 ppb (25) N/A N/A 5.0 μg/m3 (21) 25.0
 
May 5, 2021, 1 a.m. 24.0 ppb (23) 8.0 ppb (8) N/A 16.0 ppb (16) N/A N/A 23.0 ppb (22) N/A N/A 5.0 μg/m3 (21) 23.0
 
May 5, 2021, midnight 31.0 ppb (30) 12.0 ppb (12) N/A 19.0 ppb (18) N/A N/A 22.0 ppb (21) N/A N/A 5.0 μg/m3 (21) 30.0
 
May 4, 2021, 11 p.m. 25.0 ppb (24) 9.0 ppb (9) N/A 16.0 ppb (16) N/A N/A 27.0 ppb (25) N/A N/A 4.0 μg/m3 (17) 25.0
 
May 4, 2021, 10 p.m. 20.0 ppb (19) 7.0 ppb (7) N/A 14.0 ppb (14) N/A N/A 31.0 ppb (29) N/A N/A 4.0 μg/m3 (17) 29.0
 
May 4, 2021, 9 p.m. 17.0 ppb (17) 5.0 ppb (5) N/A 12.0 ppb (12) N/A N/A 33.0 ppb (31) N/A N/A 4.0 μg/m3 (17) 31.0
 
May 4, 2021, 8 p.m. 12.0 ppb (12) 4.0 ppb (4) N/A 8.0 ppb (8) N/A N/A 35.0 ppb (33) N/A N/A 4.0 μg/m3 (17) 33.0
 
May 4, 2021, 7 p.m. 6.0 ppb (6) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 38.0 ppb (36) N/A N/A 4.0 μg/m3 (17) 36.0
 
May 4, 2021, 6 p.m. 8.0 ppb (8) 2.0 ppb (2) N/A 5.0 ppb (5) N/A N/A 38.0 ppb (36) N/A N/A 5.0 μg/m3 (21) 36.0
 
May 4, 2021, 5 p.m. 6.0 ppb (6) 2.0 ppb (2) N/A 4.0 ppb (4) N/A N/A 39.0 ppb (37) N/A N/A 5.0 μg/m3 (21) 37.0
 
May 4, 2021, 4 p.m. 6.0 ppb (6) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 38.0 ppb (36) N/A N/A 5.0 μg/m3 (21) 36.0
 
May 4, 2021, 3 p.m. 4.0 ppb (4) 1.0 ppb (1) N/A 3.0 ppb (3) N/A N/A 39.0 ppb (37) N/A N/A 4.0 μg/m3 (17) 37.0
 
May 4, 2021, 2 p.m. 4.0 ppb (4) 1.0 ppb (1) N/A 3.0 ppb (3) N/A N/A 38.0 ppb (36) N/A N/A 5.0 μg/m3 (21) 36.0
 
May 4, 2021, 1 p.m. 4.0 ppb (4) 1.0 ppb (1) N/A 3.0 ppb (3) N/A N/A 37.0 ppb (35) N/A N/A 5.0 μg/m3 (21) 35.0
 
May 4, 2021, noon 7.0 ppb (7) 1.0 ppb (1) N/A 6.0 ppb (6) N/A N/A 32.0 ppb (30) N/A N/A 6.0 μg/m3 (25) 30.0
 
May 4, 2021, 11 a.m. 6.0 ppb (6) 1.0 ppb (1) N/A 5.0 ppb (5) N/A N/A 30.0 ppb (28) N/A N/A 6.0 μg/m3 (25) 28.0
 
May 4, 2021, 10 a.m. 3.0 ppb (3) 1.0 ppb (1) N/A 2.0 ppb (2) N/A N/A 33.0 ppb (31) N/A N/A 5.0 μg/m3 (21) 31.0
 
May 4, 2021, 9 a.m. 5.0 ppb (5) 1.0 ppb (1) N/A 4.0 ppb (4) N/A N/A 29.0 ppb (27) N/A N/A 6.0 μg/m3 (25) 27.0
 
May 4, 2021, 8 a.m. 6.0 ppb (6) 1.0 ppb (1) N/A 5.0 ppb (5) N/A N/A 26.0 ppb (25) N/A N/A 6.0 μg/m3 (25) 25.0
 
May 4, 2021, 7 a.m. 4.0 ppb (4) 0.0 ppb (0) N/A 4.0 ppb (4) N/A N/A 27.0 ppb (25) N/A N/A 6.0 μg/m3 (25) 25.0
 
May 4, 2021, 6 a.m. 6.0 ppb (6) 0.0 ppb (0) N/A 6.0 ppb (6) N/A N/A 22.0 ppb (21) N/A N/A 7.0 μg/m3 (30) 30.0
 
May 4, 2021, 5 a.m. 11.0 ppb (11) 2.0 ppb (2) N/A 9.0 ppb (9) N/A N/A 21.0 ppb (20) N/A N/A 7.0 μg/m3 (30) 30.0
 
May 4, 2021, 4 a.m. 14.0 ppb (14) 2.0 ppb (2) N/A 12.0 ppb (12) N/A N/A 19.0 ppb (18) N/A N/A 7.0 μg/m3 (30) 30.0
 
May 4, 2021, 3 a.m. 8.0 ppb (8) 0.0 ppb (0) N/A 8.0 ppb (8) N/A N/A 23.0 ppb (22) N/A N/A 6.0 μg/m3 (25) 25.0
 
May 4, 2021, 2 a.m. 13.0 ppb (13) 2.0 ppb (2) N/A 11.0 ppb (11) N/A N/A 26.0 ppb (25) N/A N/A 5.0 μg/m3 (21) 25.0
 
May 4, 2021, 1 a.m. 21.0 ppb (20) 6.0 ppb (6) N/A 15.0 ppb (15) N/A N/A 26.0 ppb (25) N/A N/A 5.0 μg/m3 (21) 25.0
 
May 4, 2021, midnight 22.0 ppb (21) 8.0 ppb (8) N/A 15.0 ppb (15) N/A N/A 27.0 ppb (25) N/A N/A 5.0 μg/m3 (21) 25.0