Bernardo O'Higgins Base experiences a borderline polar tundra climate (Köppen ET) that is extremely close to a polar ice cap climate (Köppen EF). Average annual precipitation amounts to 771 mm (30.35 in), and is distributed fairly evenly throughout the year, typically peaking marginally during the austral spring. Temperatures are frigid all year-round; the warmest month is January with an average monthly temperature of 1 °C (34 °F), while the coldest month is July with an average monthly temperature of −9 °C (16 °F).