Download Detailed AQS Data
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, 28.0M) as of 8/6/08. This
file unzips to a large text file (264.3M) 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, 48.3M) as of 8/6/08. This file unzips to a PDF in a report format with
one page per site (6686 pp, 64M).
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") |
2008 (As of file date) |
2007 |
2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 | 1999 | 1998 | 1997 | 1996 | 1995 | 1994 | 1993 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Carbon Monoxide (42101) RD_501_42101_yyyy.ZIP |
42101_2008 3737KB (70515KB) 7/30/08 |
42101_2007 11180KB (215388KB) 7/23/08 |
42101_2006 11352KB (224318KB) 4/9/08 |
42101_2005 12201KB (240815KB) 4/9/08 |
42101_2004 12957KB (248989KB) 8/8/08 |
42101_2003 13129KB (255802KB) 4/9/08 |
42101_2002 13849KB (261809KB) 6/20/07 |
42101_2001 14359KB (269337KB) 6/20/07 |
42101_2000 15169KB (283490KB) 6/20/07 |
42101_1999 15412KB (283883KB) 6/20/07 |
42101_1998 15827KB (290265KB) 6/20/07 |
42101_1997 15974KB (292328KB) 6/20/07 |
42101_1996 16276KB (296916KB) 6/20/07 |
42101_1995 16441KB (297692KB) 6/20/07 |
42101_1994 16138KB (290900KB) 6/20/07 |
42101_1993 15771KB (292069KB) 6/20/07 |
Lead - PB - daily (12128) RD_501_12128_yyyy.ZIP |
12128_2008 15KB (195KB) 7/24/08 |
12128_2007 64 KB (857KB) 7/24/08 |
12128_2006 75KB (1038KB) 7/24/08 |
12128_2005 75KB (1055KB) 7/24/08 |
12128_2004 75KB (1072KB) 7/24/08 |
12128_2003 73KB (1025KB) 7/24/08 |
12128_2002 74KB (1054KB) 7/24/08 |
12128_2001 71KB (991KB) 4/9/08 |
12128_2000 62KB (898KB) 6/20/07 |
12128_1999 67KB (965KB) 6/20/07 |
12128_1998 80KB (1157KB) 6/20/07 |
12128_1997 97KB (1444KB) 6/20/07 |
12128_1996 111KB (1643KB) 6/20/07 |
12128_1995 116KB (1714KB) 6/20/07 |
12128_1994 126KB (1836KB) 6/20/07 |
12128_1993 128KB (1901KB) 6/20/07 |
Nitrogen Dioxide (42602) RD_501_42602_yyyy.ZIP |
42602_2008 4184KB (75570KB) 7/24/08 |
42602_2007 12942KB (238461KB) 7/24/08 |
42602_2006 13308KB (243463KB) 7/24/08 |
42602_2005 13397KB (244266KB) 7/24/08 |
42602_2004 13569KB (248038KB) 7/25/08 |
42602_2003 13482KB (244809KB) 7/25/08 |
42602_2002 13698KB (242253KB) 6/20/07 |
42602_2001 13680KB (241294KB) 6/20/07 |
42602_2000 13589KB (239391KB) 6/20/07 |
42602_1999 13348KB (234062KB) 6/20/07 |
42602_1998 13118KB (230821KB) 6/20/07 |
42602_1997 12795KB (224328KB) 6/20/07 |
42602_1996 12474KB (217881KB) 6/20/07 |
42602_1995 12549KB (218328KB) 6/20/07 |
42602_1994 12064KB (209890KB) 6/20/07 |
42602_1993 11146KB (202966KB) 6/20/07 |
Ozone (44201) - hourly RD_501_44201_yyyy.ZIP |
44201_2008 10328KB (175359KB) 7/25/08 |
44201_2007 34016KB (582931KB) 7/25/08 |
44201_2006 33300KB (570087KB) 7/25/08 |
44201_2005 32945KB (563880KB) 7/25/08 |
44201_2004 33062KB (569078KB) 7/25/08 |
44201_2003 33120KB (566575KB) 7/25/08 |
44201_2002 32677KB (557225KB) 4/14/08 |
44201_2001 32033KB (546578KB) 4/10/08 |
44201_2000 30972KB (528441KB) 4/10/08 |
44201_1999 29970KB (510794KB) 4/10/08 |
44201_1998 29286KB (499695KB) 4/10/08 |
44201_1997 28499KB (486666KB) 4/10/08 |
44201_1996 27464KB (471434KB) 4/10/08 |
44201_1995 27598KB (473026KB) 4/10/08 |
44201_1994 26916KB (462890KB) 4/10/08 |
44201_1993 25701KB (457394KB) 4/10/08 |
Oxides of Nitrogen - NOX (42603) RD_501_42603_yyyy.ZIP |
42603_2007 3730KB (64987KB) 7/25/08 |
42603_2007 11340KB (201161KB) 7/25/08 |
42603_2006 10027KB (175689KB) 4/14/08 |
42603_2005 9910KB (172416KB) 4/14/08 |
42603_2004 9890KB (172734KB) 4/14/08 |
42603_2003 9893KB (170826KB) 4/14/08 |
42603_2002 9881KB (169769KB) 4/14/08 |
42603_2001 9443KB (161425KB) 4/14/08 |
42603_2000 9366KB (159504KB) 4/14/08 |
42603_1999 9317KB (157635KB) 4/14/08 |
42603_1998 8860KB (147512KB) 6/20/07 |
42603_1997 8587KB (142386KB) 6/20/07 |
42603_1996 8604KB (141825KB) 6/20/07 |
42603_1995 8599KB (141460KB) 6/20/07 |
42603_1994 7974KB (130624KB) 6/20/07 |
42603_1993 5302KB (88397KB) 6/20/07 |
PAMS VOC1 RD_501_PVOC_yyyy.ZIP |
PVOC_2008 8283KB (130217KB) 7/25/08 |
PVOC_2007 40150KB (627669KB) 7/25/08 |
PVOC_2006 40107KB (625932KB) 7/25/08 |
PVOC_2005 37299KB (576195KB) 4/15/08 |
PVOC_2004 33951KB (525770KB) 4/15/08 |
PVOC_2003 33335KB (511117KB) 4/15/08 |
PVOC_2002 32859KB (520882KB) 4/15/08 |
PVOC_2001 35824KB (565398KB) 4/15/08 |
PVOC_2000 31959KB (507751KB) 4/15/08 |
PVOC_1999 30649KB (481092KB) 6/20/07 |
PVOC_1998 29779KB (460632KB) 6/20/07 |
PVOC_1997 24487KB (377053KB) 6/20/07 |
PVOC_1996 19091KB (293060KB) 6/20/07 |
PVOC_1995 14124KB (217988KB) 6/20/07 |
PVOC_1994 5579KB (81662KB) 6/20/07 |
PVOC_1993 2142KB (32873KB) 6/20/07 |
PM 2.5 - Local Conditions -daily (88101) RD_501_88101_LC_Daily_ yyyy.ZIP |
88101_2008 250KB (3391KB) 7/25/08 |
88101_2007 815KB (11114KB) 7/25/08 |
88101_2006 780KB (10638KB) 7/25/08 |
88101_2005 828KB (11242KB) 7/25/08 |
88101_2004 827KB (11394KB) 7/25/08 |
88101_2003 842KB (11580KB) 7/25/08 |
88101_2002 929KB (12899KB) 7/25/08 |
88101_2001 927KB (12784KB) 7/25/08 |
88101_2000 877KB (12049KB) 7/25/08 |
88101_1999 612KB (8390KB) 7/25/08 |
88101_1998 7KB (46KB) 7/25/08 |
88101_1997 4KB (9KB) 4/10/08 |
no data reported |
no data reported |
no data reported |
no data reported |
PM Fine Speciation2,3,5 RD_501_SPEC_yyyy.ZIP |
SPEC_2008 2034KB (22968KB) 7/28/08 |
SPEC_2007 7047KB (82015KB) 7/28/08 |
SPEC_2006 7572KB (86009KB) 7/28/08 |
SPEC_2005 8791KB (99425KB) 7/28/08 |
SPEC_2004 8967KB (103438KB) 7/28/08 |
SPEC_2003 8570KB (97104KB) 7/28/08 |
SPEC_2002 7409KB (86674KB) 7/28/08 |
SPEC_2001 3483KB (41568KB) 7/28/08 |
SPEC_2000 1202KB (14336KB) 7/28/08 |
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 RB_503_Blanks_yyyy.ZIP |
BLANKS_2008 224KB (86674KB) 7/30/08 |
BLANKS_2007 908KB (11227KB) 7/30/08 |
BLANKS_2006 1161KB (14060KB) 7/30/08 |
BLANKS_2005 1384KB (16784KB) 7/30/08 |
BLANKS_2004 1584KB (20115KB) 7/30/08 |
BLANKS_2003 1414KB (17150KB) 7/30/08 |
BLANKS_2002 |
BLANKS_2001 |
BLANKS_2000 |
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_2006 8676KB (83094KB) 8/6/08 |
IMPROVE_2005 9159KB (87383KB) 8/6/08 |
IMPROVE_2004 10891KB (106412KB) 4/15/08 |
IMPROVE_2003 9984KB (96314KB) 4/15/08 |
IMPROVE_2002 9081KB (86871KB) 4/15/08 |
IMPROVE_2001 7660KB (72718KB) 4/14/08 |
IMPROVE_2000 4961KB (48511KB) 4/14/08 |
IMPROVE_1999 3651KB (38085KB) 4/15/08 |
IMPROVE_1998 3744KB (38479KB) 4/15/08 |
IMPROVE_1997 3800KB (38628KB) 4/15/08 |
IMPROVE_1996 3628KB (36872KB) 4/15/08 |
IMPROVE_1995 3540KB (4115KB) 4/15/08 |
IMPROVE_1994 3425KB (33862KB) 4/15/08 |
No data |
PM 10 (81102) RD_501_81102_yyyy.ZIP |
81102_2008 2648KB (41894KB) 7/28/08 |
81102_2007 7932KB (125012KB) 7/28/08 |
81102_2006 7928KB (124749KB) 7/28/08 |
81102_2005 7874KB (123946KB) 7/28/08 |
81102_2004 7381KB (115809KB) 7/28/08 |
81102_2003 6811KB (106311KB) 7/28/08 |
81102_2002 6479KB (101167KB) 7/28/08 |
81102_2001 6227KB (97309KB) 7/28/08 |
81102_2000 5025KB (77974KB) 7/28/08 |
81102_1999 4223KB (63890KB) 6/20/07 |
81102_1998 4569KB (70,677KB) 6/20/07 |
81102_1997 5070KB (79,252KB) 6/20/07 |
81102_1996 4550KB (71,050KB) 6/20/07 |
81102_1995 3880KB (60281KB) 6/20/07 |
81102_1994 3044KB (47042KB) 6/20/07 |
81102_1993 1919KB (29152KB) 6/20/07 |
PM 2.5 Non Reference Method -Hourly (88502) RD_501_88502_yyyy.ZIP |
88502_2008 4975KB (77114KB) 7/28/08 |
88502_2007 13856KB (217731KB) 7/28/08 |
88502_2006 10470KB (164341KB) 7/28/08 |
88502_2005 8386KB (134063KB) 7/28/08 |
88502_2004 5737KB (90161KB) 7/28/08 |
88502_2003 3735KB (58215KB) 7/28/08 |
88502_2002 2134KB (31903KB) 7/28/08 |
88502_2001 1421KB (21007KB) 7/28/08 |
88502_2000 944KB (13768KB) 7/28/08 |
88502_1999 332KB (4316KB) 7/28/08 |
88502_1998 119KB (1142KB) 7/28/08 |
88502_1997 95KB (743KB) 7/28/08 |
88502_1996 90KB (703KB) 7/28/08 |
88502_1995 90KB (677KB) 7/28/08 |
88502_1994 92KB (653KB) 7/28/08 |
88502_1993 78KB (550KB) 7/28/08 |
Reactive Oxides of Nitrogen - NOY (42600) RD_501_42600_yyyy.ZIP |
42600_2008 343KB (5104KB) 7/28/08 |
42600_2007 976KB (15063KB) 7/28/08 |
42600_2006 861KB (13468KB) 4/10/08 |
42600_2005 739KB (11744KB) 4/10/08 |
42600_2004 632KB (9810KB) 6/20/07 |
42600_2003 557KB (8970KB) 6/20/07 |
42600_2002 515KB (8120KB) 6/20/07 |
42600_2001 622KB (9763KB) 6/20/07 |
42600_2000 508KB (7915KB) 6/20/07 |
42600_1999 535KB (8291KB) 6/20/07 |
42600_1998 551KB (8898KB) 6/20/07 |
42600_1997 321KB (4861KB) 6/20/07 |
42600_1996 276KB (4182KB) 6/20/07 |
42600_1995 222KB (3394KB) 6/20/07 |
no data reported |
no data reported |
Sulfur Dioxide (42401) RD_501_42401_yyyy.ZIP (Hourly data) |
42401_2008 5240KB (104291KB) 7/28/08 |
42401_2007 16151KB (328978KB) 7/28/08 |
42401_2006 16018KB (328123KB) 7/28/08 |
42401_2005 17058KB (346884KB) 7/28/08 |
42401_2004 17372KB (352911KB) 7/28/08 |
42401_2003 16135B (316936KB) 6/20/07 |
42401_2002 16941KB (332979KB) 6/20/07 |
42401_2001 17279KB (337690KB) 6/20/07 |
42401_2000 17875KB (346577KB) 6/20/07 |
42401_1999 17341KB (369644KB) 4/10/08 |
42401_1998 19350KB (382084KB) 4/10/08 |
42401_1997 19835KB (391980KB) 4/10/08 |
42401_1996 20483KB (405536KB) 4/10/08 |
42401_1995 20794KB (402498KB) 6/20/07 |
42401_1994 21014KB (400033KB) 6/20/07 |
42401_1993 21132KB (404104KB) 6/20/07 |
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.
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.