Year,Jan.,Feb.,Mar.,Apr.,May.,Jun.,Jul.,Aug.,Sep.,Oct.,Nov.,Dec.,24-Hour Annual Avg., 1990,9836,10712,12600,13064,13584,15414,15733,16012,13913,13006,12379,9682,13006, 1991,9460,11644,12755,12941,13329,16007,16646,17212,14960,13913,12835,13092,13745, 1992,11233,12436,14430,14317,15116,18139,17437,18014,16200,15771,13787,12103,14962, 1993,10407,11912,14175,15246,16433,19720,18734,19190,16990,16348,14319,13459,15597, 1994,11929,12771,15395,15731,16847,18477,19194,19447,17482,16961,14488,13527,16042, 1995,13122,14177,15980,16247,17277,19262,19582,19973,17967,17309,15986,14427,16776, 1996,12671,14215,16794,17003,18313,19417,20313,,18880,18220,16917,14767,, 1997,13735,14863,17066,16966,17800,,,,,,,16143,, 1998,14768,16261,18158,18398,19139,21811,21505,21430,20169,19279,17960,16467,18779, 1999,15930,16275,19004,18963,20146,22412,22968,23192,20952,20275,19076,17050,19687, 2000,15288,17292,19465,19594,20660,22564,23111,23735,20859,19800,18121,16953,19787, 2001,15542,17169,19935,19866,21134,22760,22975,23593,21538,20963,19686,16790,20163, 2002,16021,18624,20640,20296,22092,23808,23683,24470,21834,21619,19702,18453,20937, 2003,16778,17989,19684,19677,21290,23617,23594,24436,21741,21319,19224,17822,20598, 2004,,17277,21203,20999,21748,23558,23970,23986,21679,21250,19613,18544,, 2005,16281,18411,20741,20569,21115,23309,23888,23488,21457,20490,19502,18021,20606, 2006,16685,18635,20676,21320,21987,23978,23930,24210,22678,21925,20871,19188,21340, 2007,17869,19469,21948,21804,22751,24307,24460,25197,23012,22585,,,, 2008,,,,,21520,22286,22413,23181,20393,19949,19243,16419,, 2009,15911,17801,19940,20500,21955,23095,24001,23590,22873,20743,19865,17616,20658, 2010,16681,18338,20481,20663,21636,23367,24567,24426,22302,21363,18861,17612,20858, 2011,16821,17936,19946,20165,21277,23129,24028,23731,22082,21150,19847,18814,20744, 2012,16852,18526,20175,20949,22313,24181,24588,24802,22402,22083,20622,18755,21354, 2013,15989,18441,21411,21062,22822,24939,24867,25444,22718,22220,20510,18913,21611, 2014,17711,18546,21779,21968,23214,25139,24883,24244,23061,22544,20925,19945,21997, 2015,18922,20878,23193,22906,24286,26603,26848,26036,24826,23754,21886,19895,23336, 2016,18985,21416,24501,24601,26322,28720,29122,28731,26733,25946,24617,19914,24967, 2017,17299,21201,26860,26313,27822,30127,30588,29959,27665,27377,25433,22681,26110, 2018,21482,22944,26233,27037,28724,31441,31143,30616,28555,27659,26360,22673,27072, 2019,21998,21467,26969,28023,29252,31762,32624,31522,29648,28874,26307,24218,27722, 2020,21856,23945,23098,17684,24287,28801,30036,30308,30557,28852,24804,23750,25665, 2021,23062,22943,28961,30199,32110,34836,35104,34094,32232,31281,30145,25790,30063, 2022,23841,26920,29923,30227,32021,33962,33251,32870,31796,31146,27959,24307,29852, 2023,24020,25697,27918,29509,32310,34532,34694,34380,32826,32268,30246,26573,30414, 2024,22443,26920, , , , , , , , , , , ,