Year,Jan.,Feb.,Mar.,Apr.,May.,Jun.,Jul.,Aug.,Sep.,Oct.,Nov.,Dec.,24-Hour Annual Avg., 1990,3211,3441,3673,3784,3744,3800,3745,4177,3852,3518,3355,3171,3623, 1991,3107,3394,3617,3719,3803,3823,3886,4289,3923,3703,3501,3610,3700, 1992,3385,3593,3869,3990,3997,3927,3938,4322,4100,3795,3509,3590,3846, 1993,3255,3458,3810,4067,4052,4022,3926,4361,4208,3876,3661,3729,3871, 1994,3539,3673,4057,4401,4141,4208,4134,4251,4258,3921,3602,3719,3993, 1995,3467,3685,3815,4037,4147,4064,4222,4277,4258,4041,3854,3944,3984, 1996,3474,3833,4056,4129,4044,3896,3969,4460,4216,3926,3843,3773,3968, 1997,3646,3832,3951,4169,4328,4526,4139,4496,4165,3886,3734,3838,4059, 1998,3547,3752,3963,4147,4147,4131,4176,4501,4313,4128,3940,4036,4065, 1999,3779,4021,4316,4490,4693,4824,4648,4616,4359,4284,4093,4249,4364, 2000,3784,4036,4185,4207,4316,4442,,,4594,4226,3776,4248,, 2001,3863,4065,4195,4346,4365,4347,4285,4667,4394,4205,4516,4225,4289, 2002,4110,3996,4369,4724,4531,4687,4496,4734,4545,4522,4121,4233,4422, 2003,3964,4098,4195,4471,4543,4612,4409,4724,4427,4322,4071,4099,4328, 2004,3836,4061,4237,4401,4367,4378,4621,4722,4419,4311,4155,4389,4325, 2005,4046,4206,4293,4433,4560,4615,4713,4802,4493,4237,4229,4352,4415, 2006,4076,4260,4307,4496,4569,4590,3708,3670,3716,4005,4131,4161,4141, 2007,3925,4140,4270,4358,4480,4214,4201,4491,4130,4073,3958,4127,4197, 2008,3863,4045,4095,4305,4414,4288,4353,4553,,4237,3984,4210,, 2009,3944,4077,4149,4501,4688,4454,4633,4792,4548,4470,4125,4369,4396, 2010,4004,4212,4625,4610,4179,4659,4791,5214,4603,4358,4109,4457,4485, 2011,4155,4261,4603,4612,4799,4916,4793,4937,4717,4586,4135,4463,4581, 2012,4068,4308,4382,4475,4407,4451,4429,4702,4887,4642,4218,4467,4453, 2013,4054,4005,4297,4474,4423,4461,4317,4940,4814,4203,3864,4097,4329, 2014,3847,4101,3975,4235,4385,4393,4245,4499,4540,4462,4129,,4148, 2015,3749,4164,4185,4389,4448,4576,4456,4695,4477,4436,4140,4449,4347, 2016,4137,4248,4415,4598,4584,4747,4565,4607,4707,4658,4318,4382,4497, 2017,4017,4322,4604,4998,6052,6475,5243,5627,5654,5579,4590,4683,5154, 2018,4278,4498,4636,5247,5483,5536,5420,5625,5401,5353,4550,4641,5056, 2019,4295,4498,4739,5652,5593,6192,5398,5815,5409,5251,4730,4423,5166, 2020,4078,4234,3867,3427,4143,4039,4388,4693,5034,4607,4176,3979,4222, 2021,3915,4093,4374,4621,4745,4752,4634,4554,4589,4480,4009,4055,4402, 2022,3793,3945,4242,4267,4506,4625,4519,4731,4578,4655,4078,4146,4339, 2023,4032,4141,4283,4648,4865,4663,4670,5096,4864,4867,4316,4412,4571, 2024,4168,4317, , , , , , , , , , , ,