Oklahoma Department of Environmental Quality
2026 Carbon Monoxide
8-Hour Daily Maximum through March 9, 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	0.5	0.3
OKC North	0.9	0.9	1.2	1.2	0.9	0.8	1.1	0.9
OKC Near Road	1.2	1.2	1.4	1.4	1.3	1.1	1.2	1.2
*All data is subject to change upon QA/QC -- data collection for 2026 is ongoing. The software function we use to pull these values is nonoperational, this chart will be updated when possible.