Lake ice clearance and formation data for Green Lakes Valley from 1981 - ongoing.

Records were based on intermittent observation of the extent of ice cover on Silver Lake, Lake Albion, and Green Lakes 1-5, dependent on observers present for other reasons. Dates of freeze-up (formation), breakup (first melt or open water). and lake-ice clearance were recorded, along with visual estimates of percent ice cover at various dates prior to complete meltout in spring. The latter estimates are not included in this data set.本数据集的记录基于对西尔弗湖（Silver Lake）、阿尔比恩湖（Lake Albion）以及1-5号绿湖（Green Lakes 1-5）冰封覆盖范围的间断性观测，相关观测由因其他事由到场的观测人员完成。记录内容包括湖泊封冻（冰层形成）、解冻（首次融冰或出现开阔水面）以及湖冰完全消融的日期，同时涵盖春季完全融冰前多个观测日期的冰层覆盖百分比目视估算值。但此类目视估算值未纳入本数据集。