1881 Minnesota tornado outbreak
On July 15–16, 1881, a deadly tornado outbreak struck southern Minnesota, featuring at least least six tornadoes, 24 deaths, and 123 injuries. The deadliest tornado of the outbreak, retroactively rated F4 on the Fujita scale, killed 20 people in and near New Ulm; it was likely a long-tracked tornado family and may have caused F5 damage to rural farmsteads. An F4 tornado elsewhere in Minnesota killed four more people, and additional strong tornadoes occurred in the state.
Confirmed tornadoes
Prior to 1990, there is a likely undercount of tornadoes, particularly E/F0–1, with reports of weaker tornadoes becoming more common as population increased. A sharp increase in the annual average E/F0–1 count by approximately 200 tornadoes was noted upon the implementation of NEXRAD Doppler weather radar in 1990–1991. 1974 marked the first year where significant tornado counts became homogenous with contemporary values, attributed to the consistent implementation of Fujita scale assessments. Numerous discrepancies on the details of tornadoes in this outbreak exist between sources. The total count of tornadoes and ratings differs from various agencies accordingly. The list below documents information from the most contemporary official sources alongside assessments from tornado historian Thomas P. Grazulis.
Bird Island–New Ulm, Minnesota
A potent, long-lived tornado family—likely of F5 intensity—devastated farms and the western side of New Ulm. It struck five farms in Wellington Township, obliterating every building on each of them and causing a few deaths. The tornado killed five more people in Cairo Township, all in one family. A boy and his herd of 40 cattle perished as well. On the Minnesota River, the tornado razed nine homes in West Newton, claiming five more lives. Observers reported two parallel damage swaths nearby, indicating two or more tornadoes in the area and possible reformation into a distinct event. Next, the tornado veered sharply to the left as it entered the western side of New Ulm, destroying that section of town, demolishing 47 structures, and killing half a dozen people. The town was hard hit, with 247 buildings damaged or destroyed; many homes in town were leveled as well. In New Ulm the tornado was up to wide, following a zigzag track.