Daily CO2 readings are updated here automatically with the latest atmospheric CO2 readings available from the Mauna Loa Observatory in Hawaii.
Data sources:
March 1958 to April 1974: Scripps Institution of Oceanography, May 1974 to present day: Dr. Pieter Tans, NOAA/GML
Last update: 3:35:02 AM on Jan. 23, 2025, Hawaii local time (UTC -10)
| Latest | One year ago | Change from previous year | ||
|---|---|---|---|---|
| Date | Reading | Date | Reading | |
| Jan. 22, 2025 | 425.77 ppm | Jan. 23, 2024 | 422.65 ppm | 3.12 ppm increase (0.74 %) |
| Jan. 21, 2025 | 426.34 ppm | Jan. 22, 2024 | 422.87 ppm | 3.47 ppm increase (0.82 %) |
| Jan. 20, 2025 | 426.74 ppm | Jan. 21, 2024 | 422.77 ppm | 3.97 ppm increase (0.94 %) |
| Jan. 19, 2025 | 428.37 ppm | Jan. 20, 2024 | 422.89 ppm | 5.48 ppm increase (1.30 %) |
| Jan. 18, 2025 | 426.76 ppm | Jan. 19, 2024 | 422.80 ppm | 3.96 ppm increase (0.94 %) |
| Jan. 17, 2025 | 425.93 ppm | Jan. 18, 2024 | 422.83 ppm | 3.10 ppm increase (0.73 %) |
| Jan. 16, 2025 | 427.67 ppm | Jan. 17, 2024 | 423.30 ppm | 4.37 ppm increase (1.03 %) |
| Jan. 15, 2025 | 426.70 ppm | Jan. 16, 2024 | 422.83 ppm | 3.87 ppm increase (0.92 %) |
| Jan. 14, 2025 | 426.24 ppm | Jan. 15, 2024 | 422.36 ppm | 3.88 ppm increase (0.92 %) |
| Jan. 13, 2025 | Unavailable | Jan. 14, 2024 | 422.85 ppm | n/a |