MENU

NOAA National Centers
for Environmental Information

State Climate Summaries

OHIO

Key Messages   Narrative   Downloads  

Ohio sunset
Photo by Lior Shapira

OHIO

Ohio’s mid-latitude location in the interior and away from the coasts of the North American continent results in a climate with a large range in temperature, with warm, humid summers and cold winters. The lack of large mountain barriers to the north or south also contributes to the range of conditions that affect the state, allowing for incursions of very cold air masses from the Arctic in the winter as well as warm and humid air masses from the Gulf of Mexico in the summer. Lake Erie has a large influence on the local climate. Near-shore locations are considerably warmer during the winter and cooler during the summer than locations farther away from the shores. Lake effect snow, caused by the warming and moistening of arctic air masses over the Great Lakes, is a hazard along the southeastern shoreline of Lake Erie.

 

Figure 1

Observed and Projected Temperature Change

VIEW

Figure 1: Observed and projected changes (compared to the 1901–1960 average) in near-surface air temperature for Ohio. Observed data are for 1900–2014. Projected changes for 2006–2100 are from global climate models for two possible futures: one in which greenhouse gas emissions continue to increase (higher emissions) and another in which greenhouse gas emissions increase at a slower rate (lower emissions). Temperatures in Ohio (orange line) have risen about 1°F since the beginning of the 20th century. Shading indicates the range of annual temperatures from the set of models. Observed temperatures are generally within the envelope of model simulations of the historical period (gray shading). Historically unprecedented warming is projected to continue through the 21st century. Less warming is expected under a lower emissions future (the coldest years being about as warm as the hottest year in the historical record; green shading) and more warming under a higher emissions future (the hottest years being about 10°F warmer than the hottest year in the historical record; red shading). Source: CICS-NC and NOAA NCEI.

Since the beginning of the 20th century, temperatures have risen 1.1°F , and temperatures in the 2000s have been warmer than any other historical period (Figure 1). The warming has not been steady. The 1930s through the mid 1950s were generally above the long-term average, followed by the coldest period on record, the 1960s and 1970s. Since the 1970s, mean annual temperature has risen by about 2°F. Based on observations through 2014, 1998 was the hottest on record, with an average annual temperature for the state of 54.1°F. The second hottest year was 2012, with an average temperature of 54.0°F. This warming has been concentrated in the winter and spring. Summers have not warmed substantially in the state, a feature characteristic of much of the Midwest. This trend is reflected in a below average occurrence of very hot days (maximum temperature above 95°F) (Figure 2a). In addition to the overall trend of higher average temperatures, the state has experienced an increase in the number of warm nights (minimum temperature above 70°F; Figure 3). Both Cleveland and Columbus have experienced statistically significant increases in the number of warm nights since 1950. Since 2000, the number has averaged 11 and 14 days per year at Cleveland and Columbus, respectively, compared to an average of 5 days per year at both cities in the 1950s through 1970s. Although both cities also experienced high temperatures in the 1930s, those temperatures were mostly due to extreme high daytime temperatures. Ohio has also experienced a below average number of very cold nights (minimum temperature below 0°F) since 1990 (Figure 2b).

Figure 2

2a-b

Figure 2a

 

Figure 2a-1

VIEW

Figure 2b

 

Figure 2b-1

VIEW
 

2c

2c

2d

Figure 2d-1

 

Figure 2d-1

VIEW

Figure 2d-2

 

Figure 2d-2

VIEW

Figure 2: The observed (a) number of very hot days (maximum temperature above 95°F), (b) number of very cold nights (minimum temperature below 0°F), (c) annual precipitation, and (d) winter and summer precipitation, averaged over 5-year periods. The values Figures 2a and b are from are averages from 26 long-term reporting stations. The values in Figures 2c and 2d are from NCEI’s version 2 climate division dataset. The dark horizontal line represents the long-term average. The number of very hot days has been below the long-term average since the mid-1950s. The number of very cold night has also been below average since the 1990s, which is indicative of winter warming. Both annual and seasonal (winter and summer) precipitation amounts have been above the long-term average in recent decades. Source: CICS-NC and NOAA NCEI.

 

Observed Number of Warm Nights

 Observed Number of Warm Nights

Figure 3: The observed number of warm nights (minimum temperature above 70°F) for 1900–2014, averaged over 5-year periods; these values are averages from 26 available long-term reporting stations. The dark horizontal line represents the long-term average. During the most recent 5-year period (2010–2014), Ohio has experienced the second highest frequency of warm nights, almost double the long-term average. This frequency was only surpassed by the extreme heat of the early 1930s. Source: CICS-NC and NOAA NCEI.

Annual precipitation varies regionally, with the northwestern part of the state averaging 32 inches each year and the south averaging 42 inches each year. Statewide average annual precipitation has ranged from a low of 26.79 inches in 1963 to a high of 55.95 inches in 2011. The driest multi-year periods were in the 1930s and 1960s, and the wettest multi-year periods have been in the 2000s (Figure 2c). Average annual precipitation during the driest and wettest 5-yr periods has ranged from a low of 33.56 inches during 1930–1934 to a high of 42.92 inches during 2003–2007. Snowfall also varies across the state, with the southern shores of Lake Erie receiving 60 inches or more annually, while the southern portion of the state receives less than 16 inches annually.

Ohio has experienced a significant increase in the number of extreme precipitation events (precipitation greater than 2 inches) since the mid 1990s (Figure 4). Past episodes of heavy rains have caused severe flooding in the state. The Great Flood of 1913 was one of the deadliest floods in U.S. history and Ohio’s greatest weather disaster. From March 23 to 26, heavy rains caused extreme runoff from soils saturated from winter storms. Levees along the Great Miami River failed, flooding the entire Great Miami River watershed. Downtown Dayton was particularly hard hit, with floodwaters reaching depths of 20 feet. The flooding caused over $70 million in damages and more than 400 people died. One of the worst floods in recent years occurred in March 1997. Between March 1 and 3, 6–12 inches of rain fell in parts of southern Ohio causing serious flooding, particularly along Brush Creek and the Scioto and Great Miami Rivers. Levels on the main stem of the Ohio River were the highest in over 30 years. Seventeen counties were declared federal disaster areas and more than 5,000 homes were damaged or destroyed, resulting in around $180 million in damages (in 1997 dollars).

 

Observed Number of Extreme Precipitation Events

Observed Number of Extreme Precipitation Events

Figure 4: The observed number of days with extreme precipitation events (precipitation greater than 2 inches) for 1900–2014, averaged over 5-year periods; these values are averages 25 long-term reporting stations. The dark horizontal line represents the long-term average. A typical station experiences 1 such event each year. Ohio has experienced a dramatic increase in the number of heavy rain events, with the past two decades experiencing the highest levels on record since the historic peak from 1910 to 1914. Source: CICS-NC and NOAA NCEI.

Dangerous storms can occur in every season and can cause major impacts, including loss of life, property damage, and disruptions to economic activity. Winter can bring snowstorms and ice storms, while convective storms (including thunderstorms, flood-producing rainstorms, hail, and tornadoes) are common in the warmer months. Although Ohio does not experience as many tornadoes as other states in the Midwest and Great Plains, the state has experienced several deadly tornado outbreaks. On June 28, 1924, Ohio’s deadliest tornado struck the towns of Sandusky and Lorain, killing 85 people and causing more than $1 billion (adjusted to 1997 dollars) in damages. Other notable storms include the Palm Sunday Outbreak (April 11, 1965) which produced 10 tornadoes in the state (4 of which were F4) and caused 60 deaths, the Xenia tornado, an F5 intensity storm in the Super Outbreak of 1974 that killed 34 people, and the outbreak of April 8–9, 1999, which produced 54 tornadoes, including an F4 intensity tornado in Blue Ash and Montgomery that killed 4 people.

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, followed by a hard freeze in April, devastated much of the state’s apple crop. This scenario was again observed in 2012, where March temperatures were 9–15°F above average for the state. A cool April again followed with hard freezes. Seasonal precipitation can vary, with no real trend in summer or winter precipitation (Figure 2d). In 2012, an intense drought across 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 year’s end, 86 of Ohio’s 88 counties had been declared drought disaster areas.

Under a higher emissions pathway, historically unprecedented warming is projected by the end of the 21st century (Figure 1). Even under a pathway of lower of greenhouse gas emissions, average annual temperatures are projected to most likely exceed historical record levels by the middle of the 21st century. However, there is a large range of temperature increases under both pathways, and under the lower pathway, a few projections are only slightly warmer than historical records. Increases in extreme heat are of 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. During July 17–24, 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, heat index values rose to between 100°F 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. The winters of 2013–2014 and 2014–2015 had average temperatures from December to February more than 3°F below average, due to persistent weather patterns bringing frigid air southward from the Arctic. Although the state averages approximately 2.3 days below 0°F annually, these two winters averaged 7.5 days. The intensity of such events is projected to decrease in the future.

Although annual precipitation projections are uncertain, winter and spring precipitation are 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 raise the risk of springtime flooding, posing a threat to Ohio’s agricultural industry by delaying planting and resulting in loss of yield.

The intensity of future droughts is projected to increase. Even if precipitation increases in the future, increases in temperature 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.

 

Projected Change in Spring Precipitation

Projected Change in Spring Precipitation

Figure 5: Climate model projections of changes (%) in spring precipitation by the middle of the 21st century compared to the late 20th century under a higher emissions pathway. Hatching represents portions of the state where the majority of climate models indicate a statistically significant change. Ohio is part of a large area of projected increases in spring precipitation in the Northeast and Midwest. Source: CICS-NC, NOAA NCEI, and NEMAC.

Lead Authors:
Rebekah Frankson, Kenneth E. Kunkel
Contributing Authors:
David Easterling and Sarah Champion
Recommended Citation:
Frankson, R., K. Kunkel, S. Champion and D. Easterling, 2017: Ohio State Climate Summary. NOAA Technical Report NESDIS 149-OH, 4 pp.

Resources

  1. Austin, G., K. Rizzo, A. Matte, and B. Finnerty, 1998: Ohio River Valley flood of March 1997, National Oceanic and Atmospheric Administration Service Assessment, 35 pp. [Available online at http://www.nws.noaa.gov/oh/Dis_Svy/OhioR_Mar97/Ohio.pdf]
  2. Brooks, H.E. and C.A. Doswell III, 2000: Normalized damage from major tornadoes in the United States: 1890-1999, National Oceanic and Atmospheric Administration /National Severe Storms Laboratory. [Available online at http://www.nssl.noaa.gov/users/brooks/public_html/damage/tdam1.html]
  3. Jackson, K.S. and S.A. Vivian, 1997: Flood of March 1997 in Southern Ohio, Columbus, Ohio, United States Geological Survey. [Available online at http://oh.water.usgs.gov/reports/Flood/flood.rpt.html]
  4. Kunkel, K.E, L.E. Stevens, S.E. Stevens, L. Sun, E. Janssen, D. Wuebbles, S.D. Hilberg, M.S. Timlin, L. Stoecker, N.E. Westcott, and J.G. Dobson, 2013: Regional Climate Trends and Scenarios for the U.S. National Climate Assessment. Part 3. Climate of the Midwest U.S., NOAA Technical Report NESDIS 142-3, 95 pp. [Available online at https://www.nesdis.noaa.gov/content/technical-reports]
  5. Midwestern Regional Climate Center, cited 2016: “(1981-2010) Maps of gridded data long-term averages; Average Temp — Ohio” [Available online at http://mrcc.isws.illinois.edu/CLIMATE/]
  6. MRCC, 2013: The great flood of 1913: 100 years later, Midwestern Regional Climate Center. [Available online at http://mrcc.isws.illinois.edu/1913Flood/storms_wx/rivers.shtml]
  7. NOAA, cited 2016. The Easter Freeze of April 2017: A Climatological Perspective and Assessment of Impacts and Services, Technical Report 2008-01, A National Oceanic and Atmospheric Administration /United States Department of Agriculture technical report, 56 pp. [Available online at http://www1.ncdc.noaa.gov/pub/data/techrpts/tr200801/tech-report-200801.pdf]
  8. NOAA, cited 2016: April 11th 1965 Palm Sunday tornado outbreak, Norther Indiana office, National Oceanic and Atmospheric Administration National Weather Service. [Available online at http://www.weather.gov/iwx/1965_palmsunday_50]
  9. NOAA, cited 2016: Climate at a Glance: U.S. Time Series, published October 2016, retrieved on October 18, 2016, National Oceanic and Atmospheric Administration National Centers for Environmental information. [Available online at http://www.ncdc.noaa.gov/cag/]
  10. NOAA, cited 2016: Climate of Ohio, National Oceanic and Atmospheric Administration. [Available online at https://www.ncdc.noaa.gov/climatenormals/clim60/states/Clim_OH_01.pdf]
  11. NOAA, cited 2016: The super outbreak of April 3-4, 1974, National Oceanic and Atmospheric Administration National Weather service. [Available online at https://www.weather.gov/iln/19740403]
  12. USDA, cited 2016: Secretarial disaster designations - CY 2012, United States Department of Agriculture. [Available online at http://www.fsa.usda.gov/Assets/USDA-FSA-Public/usdafiles/Disaster-Assist/disaster_map_cropyr_2012.pdf]
>