The 2022 eruption of the Mauna Loa volcano cut off road access to the Mauna Loa Baseline Observatory. Construction on the temporary Mauna Loa Access road was completed on 26 March, 2026.
At this time, there is no site access for the general public to the Mauna Loa Observatory and NOAA has not yet established a public opening date. GML and scientific partners are working together to bring mission critical scientific projects back online. It is still unclear when utility infrastructure will be replaced and power re-established to the site.
We will provide another update as more information becomes available.
Media contact: Theo Stein at (303) 819-7409 or theo.stein@noaa.gov.
News
2013 State of the Climate: Carbon dioxide tops 400 ppm
On May 9, 2013, the daily average concentration of carbon dioxide (CO2) in the atmosphere surpassed 400 parts per million (ppm) for the first time at the Mauna Loa Observatory in Hawaii, where the modern record of observations began back in 1958. Other Northern Hemisphere sites also reported CO2 concentrations exceeding 400 ppm in 2013. By summer, the high concentrations at these sites had dropped as vegetation began taking up carbon dioxide for photosynthesis.