Pictographic calendars called waniyetu wówapi or “winter counts” kept by several Great Plains Indian cultures (principally the Sioux or Lakota) preserve a record of events important to these peoples from roughly the seventeenth through the nineteenth centuries. A number of these memorable events include natural phenomena, such as meteor storms, eclipses, and unusual weather and climate. Examination of a selection of the available winter count records and related interpretive writings indicates that the Lakota and other native plains cultures recorded many instances of unusual weather or climate and associated impacts. An analysis of the winter count records in conjunction with observational and proxy climate records and other historical documentation suggests that the winter counts preserve a unique record of some of the most unusual and severe climate events of the early American period and provide valuable insight into the impacts upon people and their perceptions of such events in the ethnographically important region of the Great Plains.