Download Detailed AQS Data
**ALL THE FILES HAVE BEEN REPLACED DUE TO THE CONVERSION OF THE OLD EXCEPTIONAL EVENT FLAGS**
The table below provides links to files of detail data extracted from the AQS database in input transaction format. These files contain data for the entire country on a year-by-year basis, so many of them are very large files.
All data files are zipped to conserve disk space. Refer to our " Tools" page if you need assistance with file types.
Unless otherwise indicated, the unzipped text files match the Raw Data description in the input transaction format (PDF) (11 pp, 114K, About PDF), i.e., Transaction Type = RD. Hourly data is reported with Duration code = 1; Daily data is reported with Duration = 7. The files follow the naming convention of "RD_501_ppppp_yyyy.ZIP" or "RB_503_ppppp_yyyy.ZIP", where "ppppp" = AQS parameter code (or other name when multiple parameter codes are included) and "yyyy" = year of data.
A text file containing site
and monitor records (ZIP, 32.9M) as of 02/17/11. This
file unzips to a large text file (295M) using different record
types from the same
input transaction format (PDF) (11 pp, 114K,
About PDF).
Site records begin with the letter "A"; monitor records begin with "M".
There is also a file with
descriptions of sites (ZIP, 52M) as of 03/24/11. This file unzips to a PDF in a report format with
one page per site (7189 pp, 68.7M).
Data Reliability
It is important to understand that some air quality data are more reliable than others.
Various methods are used to collect the data. Some methods are reference methods, some are equivalent methods, and some are neither. As a general matter, data collected using EPA reference methods and/ or equivalent methods provide the highest quality data. Data using other methods maybe less reliable or be more uncertain. More information about reference, equivalent methods and other monitoring methods can be found at EPA's Ambient Monitoring Technology Information Center web site at www.epa.gov/ttn/amtic/ or the broader area of the Air Quality and Assessment Division at http://www.epa.gov/air/oaqps/organization/aqad/io.html .
AQS uses a unique code for each different monitoring method. You can access the table containing all monitoring method codes that describes the monitoring method. If the pollutant being measured is one of the criteria pollutants this sampling methodology code will indicate if it is a reference or equivalent method. The table is at www.epa.gov/ttn/airs/airsaqs/manuals/codedescs.htm.
Pollutant (Parameter Code) File name (substitute year for "yyyy") |
2011 | 2010 | 2009 | 2008 |
2007 |
2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 | 1999 | 1998 | 1997 | 1996 | 1995 | 1994 | 1993 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Carbon Monoxide (42101) RD_501_42101_yyyy.ZIP |
42101_2011 454 KB (7278KB) 03/28/11 |
42101_2010 4681 KB (81049KB) 03/17/11 |
42101_2009 11014 KB (200516KB) 03/17/11 |
42101_2008 11484KB (217554KB) 03/17/11 |
42101_2007 11605KB (223548KB) 03/17/11 |
42101_2006 12045KB (232272KB) 9/13/10 |
42101_2005 12866KB (247747KB) 09/17/10 |
42101_2004 13325KB (255733KB) 12/20/10 |
42101_2003 13799KB (262356KB) 4/30/10 |
42101_2002 14504KB (274017KB) 4/30/10 |
42101_2001 15091KB (282691KB) 4/30/10 |
42101_2000 15954KB (297669KB) 4/30/10 |
42101_1999 16114KB (29428KB) 4/30/10 |
42101_1998 16590KB (303718KB) 4/30/10 |
42101_1997 16700KB (305235KB) 4/30/10 |
42101_1996 16863KB (307367KB) 4/30/10 |
42101_1995 16889KB (305667KB) 4/30/10 |
42101_1994 16571KB (297878KB) 4/30/10 |
42101_1993 16221KB (300149KB) 4/30/10 |
Lead - PB - daily (12128) RD_501_12128_yyyy.ZIP |
12128_2011 .5k (2KB) 03/28/11 |
12128_2010 17k (209KB) 03/17/11 |
12128_2009 38KB (520KB) 03/17/11 |
12128_2008 71KB (948KB) 03/17/11 |
12128_2007 73 KB (975KB) 03/17/11 |
12128_2006 82KB (1138KB) 9/29/10 |
12128_2005 81KB (1136KB) 9/29/10 |
12128_2004 78KB (1105KB) 9/29/10 |
12128_2003 72KB (1032KB) 9/29/10 |
12128_2002 74KB (1065KB) 9/29/10 |
12128_2001 71KB (1008KB) 4/30/10 |
12128_2000 66KB (999KB) 4/30/10 |
12128_1999 72KB (1011KB) 4/30/10 |
12128_1998 85KB (1261KB) 4/30/10 |
12128_1997 102KB (1546KB) 4/30/10 |
12128_1996 116KB (1752KB) 4/30/10 |
12128_1995 121KB (1809KB) 4/30/10 |
12128_1994 131KB (1939KB) 4/30/10 |
12128_1993 134KB (2004KB) 03/18/10 |
Lead from TSP-(PB TSP) daily (14129) RD_501_14129_yyyy.ZIP |
14129_2011 .5 KB (3KB) 03/28/11 |
14129_2010 66 KB (858KB) 03/17/11 |
14129 2009 39KB (512KB) 03/17/11 |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
Nitrogen Dioxide (42602) RD_501_42602_yyyy.ZIP |
42602_2011 372 KB (5879KB) 03/28/11 |
42602_2010 12450 KB (209224KB) 03/17/11 |
42602_2009 13470KB (232487KB) 03/17/11 |
42602_2008 13622KB (242034KB) 03/17/11 |
42602_2007 13644KB (245250KB) 03/17/11 |
42602_2006 13917KB (248494KB) 03/17/11 |
42602_2005 14021KB (249640KB) 03/17/11 |
42602_2004 14198KB (253548KB) 03/17/11 |
42602_2003 14103KB (250133KB) 03/17/11 |
42602_2002 14313KB (253309KB) 03/17/11 |
42602_2001 14292KB (252212KB) 03/17/11 |
42602_2000 14202KB (250374KB) 03/17/11 |
42602_1999 13928KB (244225KB) 05/03/10 |
42602_1998 13709KB (241171KB) 05/03/10 |
42602_1997 13357KB (234150KB) 05/03/10 |
42602_1996 12885KB (225170KB) 05/03/10 |
42602_1995 12850KB (223615KB) 05/03/10 |
42602_1994 12350KB (214924KB) 03/19/10 |
42602_1993 11410KB (207834KB) 03/19/10 |
Ozone (44201) - hourly RD_501_44201_yyyy.ZIP |
44201_2011 936 KB (15017KB) 03/28/11 |
44201_2010 37040 KB (580691KB) 03/17/11 |
44201_2009 37131KB (598919KB) 03/17/11 |
44201_2008 35952KB (595254KB) 03/17/11 |
44201_2007 35393KB (592707KB) 03/17/11 |
44201_2006 34521KB (577753KB) 03/17/11 |
44201_2005 34171KB (571826KB) 03/17/11 |
44201_2004 34293KB (576694KB) 03/17/11 |
44201_2003 34305KB (573415KB) 09/16/10 |
44201_2002 33845KB (564171KB) 09/16/10 |
44201_2001 33208KB (553675KB) 09/16/10 |
44201_2000 32152KB (536082KB) 03/17/11 |
44201_1999 31629KB (516593KB) 05/03/10 |
44201_1998 30369KB (506172KB) 05/03/10 |
44201_1997 29536KB (492660KB) 09/16/10 |
44201_1996 28350KB (475202KB) 05/03/10 |
44201_1995 28307KB (473813KB) 05/03/10 |
44201_1994 27604KB (463624KB) 05/03/10 |
44201_1993 26315KB (457394KB) 03/22/10 |
Oxides of Nitrogen - NOX (42603) RD_501_42603_yyyy.ZIP |
42603_2011 325 KB (4889KB) 03/28/11 |
42603_2010 11200 KB (184773KB) 03/21/11 |
42603_2009 12258 KB (203701KB) 03/21/11 |
42603_2008 12255KB (210325KB) 03/21/11 |
42603_2007 12044KB (208592KB) 03/21/11 |
42603_2006 10620KB (181694KB) 09/16/10 |
42603_2005 10461KB (177721KB) 09/16/10 |
42603_2004 10434KB (179108KB) 05/05/10 |
42603_2003 10413KB (175607KB) 05/05/10 |
42603_2002 10409KB (174900KB) 05/05/10 |
42603_2001 9979KB (166840KB) 05/05/10 |
42603_2000 9901KB (164951KB) 05/05/10 |
42603_1999 9866KB (163132KB) 09/16/10 |
42603_1998 9416KB (156798KB) 09/16/10 |
42603_1997 9129KB (151451KB) 09/16/10 |
42603_1996 8989KB (14357KB) 09/16/10 |
42603_1995 8813KB (145045KB) 09/16/10 |
42603_1994 8162KB (133755KB) 05/05/10 |
42603_1993 5426KB (90515KB) 3/25/10 |
PAMS VOC1 RD_501_PAMS VOC_yyyy.ZIP |
PVOC 2011 35785 KB (565725KB) 03/28/11 |
PVOC 2010 34306 KB (544000KB) 03/21/11 |
PVOC_2009 39051KB (611804KB) 03/21/11 |
PVOC_2008 39326KB (613039KB) 03/21/11 |
PVOC_2007 43325KB (664027KB) 03/21/11 |
PVOC_2006 41151KB (627076KB) 03/21/11 |
PVOC_2005 38199KB (576387KB) 03/21/11 |
PVOC_2004 34803KB (526181KB) 03/21/11 |
PVOC_2003 34157KB (511560KB) 03/21/11 |
PVOC_2002 33661KB (521077KB) 03/21/11 |
PVOC_2001 36691KB (565563KB) 03/21/11 |
PVOC_2000 32731KB (507879KB) 03/21/11 |
PVOC_1999 31388KB (492740KB) 05/06/10 |
PVOC_1998 30508KB (471894KB) 05/06/10 |
PVOC_1997 25102KB (386472KB) 05/06/10 |
PVOC_1996 19572KB (300425KB) 05/06/10 |
PVOC_1995 14472KB (223349KB) 05/06/10 |
PVOC_1994 5715KB (83678KB) 05/06/10 |
PVOC_1993 2193KB (33724KB) 4/1/10 |
PM 2.5 - Local Conditions (88101) RD_501_88101_yyyy.ZIP |
88101_2011 289 KB (4313KB) 03/28/11 |
88101_2010 6065 KB (93922KB) 03/22/11 |
88101_2009 3631KB (56575KB) 03/22/11 |
88101_2008 1155KB (16391KB) 03/22/11 |
88101_2007 837KB (11186KB) 03/22/11 |
88101_2006 799KB (10680KB) 10/1/10 |
88101_2005 847KB (11257KB) 10/1/10 |
88101_2004 845KB (11408KB) 10/1/10 |
88101_2003 860KB (11594KB) 10/1/10 |
88101_2002 950KB (12913KB) 10/1/10 |
88101_2001 947KB (12797KB) 10/1/10 |
88101_2000 896KB (12056KB) 10/1/10 |
88101_1999 624KB (8392KB) 10/1/10 |
88101_1998 4KB (48KB) 6/04/09 |
88101_1997 4KB (9KB) 4/2/10 |
no data reported |
no data reported |
no data reported |
no data reported |
PM Fine Speciation2,3,5 RD_501_SPEC_yyyy.ZIP |
SPEC_2011 1.7 KB (19KB) 03/27/11 |
SPEC_2010 5783 KB (63391KB) 03/22/11 |
SPEC_2009 6240KB (68605KB) 03/22/11 |
SPEC_2008 6915KB (80947KB) 03/22/11 |
SPEC_2007 7085KB (80666KB) 09/17/10 |
SPEC_2006 7750KB (86013KB) 09/17/10 |
SPEC_2005 8999KB (99430KB) 09/17/10 |
SPEC_2004 9178KB (103442KB) 09/17/10 |
SPEC_2003 8762KB (97091KB) 09/17/10 |
SPEC_2002 7568KB (86644KB) 09/17/10 |
SPEC_2001 3555KB (42552KB) 09/17/10 |
SPEC_2000 1197KB (14330KB) 09/17/10 |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
PM Fine Speciation-Blanks6 RD_503_Blanks_yyyy.ZIP |
No Data Reported |
BLANKS_2010 798KB (10863KB) 03/22/11 |
BLANKS_2009 700KB (9259KB) 03/22/11 |
BLANKS_2008 717KB (9259KB) 03/22/11 |
BLANKS_2007 979KB (12034KB) 03/22/11 |
BLANKS_2006 1186KB (14060KB) 03/22/11 |
BLANKS_2005 1414KB (16784KB) 10/1/10 |
BLANKS_2004 1619KB (20115KB) 10/1/10 |
BLANKS_2003 1441KB (17148KB) 10/1/10 |
BLANKS_2002 1025KB (11994KB) 10/1/10 |
BLANKS_2001 514KB (71484KB) 10/1/10 |
BLANKS_2000 126KB (1658KB) 10/1/10 |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
no data reported |
PM Fine Speciation-IMPROVE7 RD_501_IMPROVE_yyyy.ZIP |
No Data Reported |
No Data Reported |
IMPROVE_2009 7105 KB (72406KB) 03/23/11 |
IMPROVE_2008 7226KB (72858KB) 03/23/11 |
IMPROVE_2007 8854KB (85581KB) 03/23/11 |
IMPROVE_2006 8566KB (81956KB) 03/23/11 |
IMPROVE_2005 9050KB (86335KB) 03/23/11 |
IMPROVE_2004 10911KB (104936KB) 03/23/11 |
IMPROVE_2003 9991KB (94935KB) 03/23/11 |
IMPROVE_2002 9090KB (85601KB) 03/23/11 |
IMPROVE_2001 7651KB (71484KB) 03/23/11 |
IMPROVE_2000 4960KB (47694KB) 10/1/10 |
IMPROVE_1999 3668KB (37661KB) 10/1/10 |
IMPROVE_1998 3757KB (38032KB) 10/1/10 |
IMPROVE_1997 3816KB (38172KB) 10/1/10 |
IMPROVE_1996 3642KB (36436KB) 10/1/10 |
IMPROVE_1995 3554KB (35289KB) 10/1/10 |
IMPROVE_1994 3437KB (33450KB) 10/1/10 |
IMPROVE_1993 2914KB (28455KB) 10/1/10 |
PM 10 (81102) RD_501_81102_yyyy.ZIP |
81102_2011 213 KB (3345KB) 03/28/11 |
81102_2010 8788 KB (131152KB) 03/23/11 |
81102_2009 9279KB (141373KB) 03/23/11 |
81102_2008 8883KB (136308KB) 03/23/11 |
81102_2007 8391KB (129251KB) 10/12/10 |
81102_2006 8333KB (128192KB) 10/12/10 |
81102_2005 8175KB (125694KB) 10/7/10 |
81102_2004 7586KB (116266KB) 10/7/10 |
81102_2003 6999KB (106660KB) 10/7/10 |
81102_2002 6639KB (101271KB) 10/7/10 |
81102_2001 6382KB (97413KB) 10/7/10 |
81102_2000 5151KB (78079KB) 10/7/10 |
81102_1999 4329KB (65520KB) 10/7/10 |
81102_1998 4682KB (72454KB) 10/7/10 |
81102_1997 5194KB (81215KB) 10/7/10 |
81102_1996 4659KB (72796KB) 05/06/10 |
81102_1995 3972KB (61752KB) 05/06/10 |
81102_1994 3116KB (48195KB) 05/06/10 |
81102_1993 1963KB (29861KB) 05/06/10 |
PM 2.5 Non Reference Method -Hourly (88501 & 88502 ) RD_501_88501_2_yyyy.ZIP |
88501/2 2011 1255 KB (18122KB) 03/28/11 |
88501/2 2010 25568 KB (385114KB) 03/23/11 |
88501/2_2009 27303KB (413642KB) 03/23/11 |
88501/2_2008 26933KB (416504KB) 03/23/11 |
88501/2 2007 24769KB (382249KB) 03/23/11 |
88501/2_2006 20353KB (316682KB) 03/23/11 |
88501/2_2005 18071KB (280894KB) 03/23/11 |
88501/2_2004 15495KB (240986KB) 03/23/11 |
88501/2_2003 12037KB (193075KB) 03/23/11 |
88501/2_2002 8741KB (137352KB) 03/23/11 |
88501/2_2001 6092KB (95154KB) 03/23/11 |
88501/2_2000 3691KB (56681KB) 10/13/10 |
88501/2_1999 1060KB (16410KB) 5/14/10 |
88501/2_1998 208KB (3345KB) 5/14/10 |
88501/2_1997 42KB (734KB) 5/14/10 |
no data reported |
no data reported |
no data reported |
no data reported |
Reactive Oxides of Nitrogen - NOY (42600) RD_501_42600_yyyy.ZIP |
42600_2011 81KB (1180KB) 03/28/11 |
42600_2010 1516 KB (22350KB) 03/21/11 |
42600_2009 1420KB (20929KB) 03/21/11 |
42600_2008 1335KB (19554KB) 4/7/10 |
42600_2007 1023KB (15140KB) 05/06/10 |
42600_2006 878KB (13468KB) 05/06/10 |
42600_2005 745KB (11744KB) 4/7/10 |
42600_2004 644KB (10041KB) 4/7/10 |
42600_2003 567KB (9182KB) 4/7/10 |
42600_2002 524KB (8311KB) 4/7/10 |
42600_2001 633KB (9994KB) 4/7/10 |
42600_2000 517KB (8101KB) 4/7/10 |
42600_1999 544KB (8486KB) 4/7/10 |
42600_1998 561KB (9108KB) 4/7/10 |
42600_1997 325KB (4973KB) 4/7/10 |
42600_1996 280KB (4279KB) 4/7/10 |
42600_1995 224KB (3472KB) 4/7/10 |
no data reported |
no data reported |
Sulfur Dioxide (42401) RD_501_42401_ 1H_yyyy.ZIP (Hourly data) |
42401 2011 635KB (11128KB) 03/28/11 |
42401 2010 13302KB (257089KB) 03/23/11 |
42401_2009 13973KB (275189KB) 03/23/11 |
42401_2008 14853KB (292350KB) 03/23/11 |
42401_2007 15664KB (309245KB) 03/23/11 |
42401_2006 15480KB (307893KB) 03/23/11 |
42401_2005 16024KB (316340KB) 03/23/11 |
42401_2004 16353KB (322704KB) 09/13/10 |
42401_2003 18289KB (360213KB) 05/06/10 |
42401_2002 22145KB (437885KB) 05/06/10 |
42401_2001 18455KB (360265KB) 05/06/10 |
42401_2000 19038KB (366918KB) 05/06/10 |
42401_1999 19643KB (373825KB) 05/06/10 |
42401_1998 20058KB (386980KB) 05/06/10 |
42401_1997 20537KB (396496KB) 05/06/10 |
42401_1996 21075KB (407630KB) 05/06/10 |
42401_1995 21343KB (412689KB) 05/06/10 |
42401_1994 21562KB (410096KB) 4/7/10 |
42401_1993 21680KB (414204KB) 4/7/10 |
Sulfur Dioxide (42401) RD_501_42401_5M_yyyy.ZIP (5 minute data) |
42401 2011 2869KB (429513KB) 03/28/11 |
42401 2010 20765KB (121096KB) 03/23/11 |
42401_2009 775KB (15658KB) 03/23/11 |
42401_2008 1087KB (22404KB) 03/23/11 |
42401_2007 1455KB (30298KB) 03/23/11 |
42401_2006 1462KB (30490KB) 03/23/11 |
42401_2005 1887KB (39611KB) 03/23/11 |
42401_2004 1953KB (40540KB) 03/24/11 |
42401_2003 1608KB (32639KB) 03/24/11 |
42401_2002 4523KB (91482KB) 03/24/11 |
42401_2001 519KB (9585KB) 03/24/11 |
42401_2000 486KB (7121KB) 03/24/11 |
42401_1999 532KB (5666KB) 03/24/11 |
42401_1998 20058KB (386980KB) 05/06/10 |
42401_1997 20537KB (396496KB) 05/06/10 |
42401_1996 21075KB (407630KB) 05/06/10 |
42401_1995 21343KB (412689KB) 05/06/10 |
42401_1994 21562KB (410096KB) 4/7/10 |
42401_1993 21680KB (414204KB) 4/7/10 |
1 parmcodesbyclasscode.xls (9/27/07, 84K) Look in spreadsheet for "Volatile Organic Compound subset of the PAMS Parameters"
2 parmcodesbyclasscode.xls (9/27/07, 84K) Look in spreadsheet for "PM2.5 Speciation"
3 Current speciation data files contain the "raw" speciation data from the national PM2.5 network. The organic carbon data are reported as measured and have not been blank-corrected. The EPA is currently exploring options for correcting carbon data. Guidance will be posted when available. Please review the attached technical note from Phil Lorang.
4 "RD_501_88101_LC_Daily_yyyy.ZIP" - These data files on the AQS web site contain the data collected by EPA approved reference and equivalent methods for sampling for PM2.5. This is the highest quality data . These samples are collected for 24-hrs from midnight to midnight local standard time either every day, every 3rd day or every 6th day. This is the data that is used by EPA to determine whether an area is in attainment or nonattainment of the National Ambient Air Quality standards. Hourly PM2.5 samples are no longer provided here, though they are available upon request. These data have more uncertainty associated with them which the user should be aware of. For example, these data are not collected with approved referenced or equivalent methods so the data should not be compared with the standards for attainment determinations or other regulatory purposes. These samplers are more variable in the data quality with the dependency including more variation dependent on the particulate composition. Also, some of this data has been corrected for sampler variation by the submitting agencies while other data submitted by other agencies has not been. (The sampling method code can provide some insight into what correction has been applied.) The continuous PM2.5 samplers report hourly averages which must be summarized to compute a midnight to midnight average.
5 "RD_501_SPEC_yyyy.ZIP" - These files contain the PM2.5 data concentrations as well as analysis of the particulate for metals, sulfate, nitrate, carbon, etc. that helps to determine what is the main cause of the particulate concentrations. These data (including the different chemical analysis that are performed) are not collected with EPA approved reference or equivalent methods, but rather methods designed specifically for this type of analyses and as such for PM2.5. There is more uncertainty associated with these data. These data are generally not used for regulatory purposes but more for research and to assist in control strategy development. These samples are collected with 24-hr samplers midnight to midnight local standard time with different sampling frequencies depending on the site location.
6 "RD_503_Blanks_yyyy.ZIP" (PM Fine Speciation-Blanks) - The Blanks data files are for the PM2.5 speciation sites and parameters, and reflect the concentrations of the individual species determined for both “TRIP” and “FIELD”. These data values are reported to AQS beginning in 2003. These files use a different format - "RB" instead of RD. The "503" in the file names also indicates this different format.
7 "RD_501_IMPROVE_yyyy.ZIP" (PM Fine Speciation–IMPROVE) - The “Interagency Monitoring of Protected Visual Environments” data for 1988 to 2004 (also available from http://vista.cira.colostate.edu/IMPROVE/) are available here in AQS format to simplify the combined analysis with the PM2.5 speciation data. Data for earlier years not included in the table above are available upon request.
SO2 is displayed Hourly
More information about PM2.5 monitoring methods can be found on EPA's Ambient Monitoring Technology Center web site at www.epa.gov/ttn/amtic. Information about the new PM rule is available at http://epa.gov/pm/actions.html.
New files may be added from time to time, and some files may be updated from time to time. Files for the more current years, will be updated 30 - 45 days after the end of a calendar quarter. The date of extraction for each file is noted in the table above along with the file name and size.
File names beginning with "RD_501" indicate the file was created using the AMP501 - Extract Raw Data Report. AMP501 produces a zipped file that includes a "pdf" file that is actually the cover page showing the criteria used to create the file, and a "txt" file with the reported sample values.
File names beginning with "RB_503" indicate the file was created using the AMP503 - Extract Blanks Data Report. Like AMP501, AMP503 produces a zipped file that includes a "pdf" file that is the cover page showing the criteria used to create the file, and a "txt" file with the reported sample values.
If you find an error in AQS, we hope you will let us know so that we may correct it. You may use the Contact Us link or you may contact the people directly responsible for the data. Air monitoring: state environmental agencies
For data not otherwise available, please use the AQS Data Mart.