Oklahoma Department of Environmental Quality
2026 Carbon Monoxide
8-Hour Daily Maximum through January 25, 2026
Standard: 8-hour daily maximums shall not exceed 9 ppm more than once per year.
Site	Highest 8-hour Maximums (ppm)
	2023		2024		2025		2026*
	1st	2nd	1st	2nd	1st	2nd	1st	2nd
Tulsa Central**	1.0	1.0	1.1	0.9	0.7	0.7	0.0	0.0
OKC North	0.9	0.9	1.2	1.2	0.9	0.8	0.8	0.6
OKC Near Road	1.2	1.2	1.4	1.4	1.3	1.1	0.9	0.9
*All data is subject to change upon QA/QC -- data collection for 2026 is ongoing.