The coastal plain at the end of Chain of Craters Road is often hot, dry, and windy. Bring rain gear, light sweaters and windbreakers, sturdy shoes, hats, water bottles, sun glasses and high UV factor sunscreen. In the Mauna Loa backcountry, be prepared for severe weather conditions any time of year, including blizzards, whiteouts, snow and driving rain. Temperatures drop below freezing at night. Do not lose sight of the ahu behind you and you look for the ahu ahead, as it is easy to become disoriented.
Sunlight is intense, especially with snow cover.
Pace yourself as you ascend Mauna Loa, and be prepared for rigorous conditions. Altitude sickness is common there, so be ready for the necessity of moving back to lower elevations. Eruptions are possible at any time. Always stay upslope from active lava flows and remain on higher ground. Stay upwind of volcanic gases.