Ohio - State Climate Summaries 2022

Agriculture is an important component of Ohio’s economy, and this sector is particularly vulnerable to extreme weather conditions. In 2007, unusually warm March temperatures were followed by a hard freeze in April, which devastated much of the state’s apple crop. This scenario was again observed in 2012, when March temperatures were 9° to 15°F above average for the state but a cool April followed, with hard freezes. Seasonal precipitation can vary, with no real trend in winter or summer precipitation (Figures 2d and 2e). In 2012, an intense drought throughout the Midwest had severe impacts on Ohio. Rainfall totals for the summer were several inches below average. In addition to low precipitation, the period from January to June was the warmest in 120 years of record, with the warm temperatures compounding the dry conditions. By the end of the year, 86 of Ohio’s 88 counties had been declared drought disaster areas.

Under a higher emissions pathway, historically unprecedented warming is projected to continue through this century (Figure 1). Even under a lower emissions pathway, annual average temperatures are projected to most likely exceed historical record levels by the middle of this century. However, a large range of temperature increases is projected under both pathways, and under the lower pathway, a few projections are only slightly warmer than historical records. Increases in extreme heat are a particular concern for Cincinnati, Columbus, and other urban areas, where the urban heat island effect raises summer temperatures. High temperatures combined with high humidity can create dangerous heat index values. From July 17 to 24, 2011, the Ohio River Valley experienced a prolonged heat wave. With temperatures above 90°F for several days in a row and dewpoints in the mid to upper 70s (°F), heat index values rose to between 100° and 110°F during the day. These occurrences are likely to become more common as temperatures continue to rise. However, there have been exceptionally cold winters in recent years. During the winters of 2013–2014 and 2014–2015, persistent weather patterns brought frigid air southward from the Arctic, causing temperatures from December to February to be more than 3°F below average. Although the state averages approximately 6 very cold nights annually, these two winters averaged 18 very cold nights. The intensity of such events is projected to decrease in the future.

Although annual precipitation projections are uncertain, winter and spring precipitation is projected to increase (Figure 5). In addition, extreme precipitation is projected to increase, potentially causing more frequent and intense floods. Heavier precipitation and higher temperatures increase the risk of springtime flooding, posing a threat to Ohio’s agricultural industry by delaying planting and resulting in a loss of yield.

The intensity of future droughts is projected to increase. Even if precipitation increases in the future, rising temperatures will increase the rate of loss of soil moisture during dry spells. Thus, future summer droughts, a natural part of the Ohio climate, are likely to be more intense.