| Oklahoma Department of Environmental Quality | ||||||
| 2026 SO2 | ||||||
| 4th Highest 1-Hour Average through October 18, 2026 | ||||||
| Standard: The 99th percentile of 1-hour daily max concentrations averaged across 3 years must be below 75 ppb. | ||||||
| Site | 99th Percentile (ppb) | 3-Yr Avg. | ||||
| 2023 | 2024 | 2025 | 2026* | 23-25 | 24-26* | |
| Ponca City | 5.0 | 7.0 | 9.0 | 4.0 | 7.0 | 6.7 |
| OKC North | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| Tulsa Newblock | 8.0 | 4.0 | 4.0 | 6.0 | 5.3 | 4.7 |
| Tulsa TCWD | 5.0 | 1.0 | 2.0 | 1.0 | 2.7 | 1.3 |
| Tulsa Central | 3.1 | 2.8 | 1.6 | 1.4 | 2.5 | 1.9 |
| Oxbow/Kremlin | 37.0 | 47.0 | 28.0 | 53.0 | 37.3 | 42.7 |
| 4th highs are considered 99th percentile until end of year data completeness is calculated. *All data is subject to change upon QA/QC -- data collection for the current year is ongoing. | ||||||