From June 8âÂÂ10, 1974, a significant tornado outbreak affected portions of the southern Great Plains and the Upper Midwest. The outbreak produced 42 tornadoes, at least 24 of them significant or intense, and is the second-deadliest June tornado event in Oklahoma history, with 16 deaths reported in the state, second only to the 35 people killed by an F4 tornado on June 12, 1942, in Oklahoma City. The deadliest tornado of the outbreak was a powerful F4 that struck the town of Drumright in Oklahoma, killing 14 people, 12 of whom were killed at Drumright. Another deadly and destructive F4 tornado struck the town of Emporia in Kansas, killing six more people. The outbreak also produced two F3 tornadoes in the Tulsa metropolitan area that, combined with flooding, produced the costliest natural disaster in that city's history up to that timeâÂÂa disaster worth $30,000,000 (1974 USD). Tornadoes hit Oklahoma City five times, a single-day record for the city as of 2010.
Prior to 1990, there is a likely undercount of tornadoes, particularly E/F0âÂÂ1, with reports of weaker tornadoes becoming more common as population increased. A sharp increase in the annual average E/F0âÂÂ1 count by approximately 200 tornadoes was noted upon the implementation of NEXRAD Doppler weather radar in 1990âÂÂ1991. 1974 marked the first year where significant tornado (E/F2+) 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.