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State Climate Summaries

INDIANA

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INDIANA

 

Figure 1

Observed and Projected Temperature Change

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Observed and projected changes (compared to the 1901–1960 average) in near-surface air temperature for Indiana. 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 Indiana (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 during 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 11°F warmer than the hottest year in the historical record; red shading). Source: CICS-NC and NOAA NCEI.

Indiana’s location in the interior of the North American continent exposes it to a climate with large ranges in temperature, resulting in warm, humid summers and cold winters. The lack of mountains to the north or south allows very cold air masses from the Arctic in the winter and warm, humid air masses from the Gulf of Mexico in the summer to move into the state, further increasing the range of conditions that affect Indiana. Average annual temperature ranges about 10°F from north to south. Lake Michigan moderates the temperature of the far northwest portion of the state, causing cooler summers and warmer winters. Lake Michigan also is the source of lake-effect snows, which can extend as far inland as Elkhart (north-central Indiana).

Since the beginning of the 20th century, temperatures in Indiana have risen approximately 1°F (Figure 1). Temperatures in the 2000s have been higher than any other historical period with the exception of the early 1930s “Dust Bowl” era. Warming has been concentrated in winter and spring while summers have not warmed substantially in the state, a feature characteristic of much of the Midwest (Figure 2a). The lack of summer warming is reflected in a below average occurrence of very hot days (maximum temperature above 95°F) (Figure 2b) although the number of very warm nights (minimum temperature above 75°F) has been average since the mid 1990s (Figure 2c). Due to extreme drought and poor land management practices, the summers of the 1930s remain the warmest on record. The winter warming trend is reflected in a below average number of very cold nights (minimum temperature below 0°F) since the 1990s (Figure 3).

Figure 2

2a

Figure 2a-1

 

Observed Spring Temperature

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Figure 2a-2

 

Observed Summer Temperature

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2b

2b
 

2c

2c

2d

Figure 2d-1

 

Observed Spring Precipitation

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Figure 2d-2

 

Observed Summer Precipitation

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Figure 2: The observed a) spring and summer temperatures, b) number of very hot days (maximum temperature above 95°F), c) number of very warm nights (minimum temperature above 75°F), and d) spring and summer precipitation, averaged over 5-year periods; the dark horizontal lines represent the long-term average. The values in Figures 2a and 2d are from NCEI’s version 2 climate division dataset. Values in Figures 2b and 2c are averages from 21 available long-term reporting stations. Since 1955, Indiana has experienced a below average number of very hot days and a generally upward trend in very warm nights. Additionally, the state has generally experienced an upward trend in seasonal temperatures and precipitation. Source: CICS-NC and NOAA NCEI.

 

Observed Number of Very Cold Nights

Observed Number of Very Cold Nights

Figure 3: The observed number of very cold nights (annual number of days with minimum temperature below 0°F) for 1900–2014, averaged over 5-year periods; these values are averages from 21 available long-term reporting stations. The dark horizontal line represents the long-term average. The number of extremely cold nights has been below average since the 1990s. From 2005 to 2009, the number of days with minimum temperature less than 0°F was about half of the long-term average, indicative of overall winter warming in the region. Source: CICS-NC and NOAA NCEI.

Annual precipitation has varied from a low of 29.11 inches in 1963 to a high of 55.21 inches in 2011. The driest multi-year periods were in the 1930s, 1940s, and 1960s, and the wettest in the 2000s (Figure 4). The driest 5-year period was 1940-1944 and the wettest was 2007-2011. Annual precipitation also varies widely across the state, ranging from 47 inches annually in the south to 37 inches in the north. For snowfall, the pattern is reversed, with the southwest averaging 14 inches, while some northern locations near Lake Michigan average over 70 inches. The proximity to Lake Michigan occasionally results in heavy winter precipitation from lake-effect snows. On January 21–22, 2014, a lake-effect storm dropped 18 inches of snow in Gary over a 5-hour period.

 

Observed Annual Precipitation

Observed Annual Precipitation

Figure 4: The observed annual precipitation across Indiana for 1895–2014, averaged over 5-year periods; these values are from NCEI's version 2 climate division dataset. Annual precipitation varies widely, but has been above average since 1990. The dark horizontal line represents the long-term average. Annual precipitation during the driest period on record (1940–1944) averaged 35.16 inches, while 46.03 inches was the annual average during the wettest period (2007–2011). 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 snow and ice storms, while convective storms capable of producing floods, hail, and tornadoes are common in the warmer months. One of the state’s worst winter storms occurred on December 22–23, 2004. More than 20 inches of snow fell across the southern part of the state. Many locations reported record snowfall amounts, including the city of Washington, with 32 inches of snow. With temperatures below freezing, the snow lingered for several days, shutting down airports and interstates and stranding holiday travelers. The storm killed 5 people and a state of emergency was declared for 50 counties.

Indiana has a long and deadly history of tornadic storms. On March 18, 1925, the deadliest tornado in U.S. history—the “Tri-State Tornado”—struck southwestern Indiana after tracking across Missouri and Illinois. The tornado destroyed parts of Griffin, Owensville, and Princeton and caused hundreds of injuries and 76 deaths. The Palm Sunday Outbreak on April 11, 1965 included several tornadoes in Indiana, eight of them at F4 intensity. The outbreak injured hundreds in the state and killed more than 130 people. Indiana’s largest tornado outbreak occurred on June 2, 1990, when 37 tornadoes occurred, several of which were classified as F4 intensity.

Agriculture is an important sector of Indiana’s economy and is particularly vulnerable to a variety of extreme weather conditions. In 2007, unusually warm March temperatures, followed by a hard freeze in April, devastated much of the state’s fruit crops, with total agricultural losses estimated at $48 million. In 2012, a large drought across the Midwest severely impacted the state. Rainfall for May, June, and July totaled 6.57 inches, more than 5 inches below average, and the 4th driest such period (after 1936, 1930, and 1988) in 120 years of record. By early August, almost 70% of the state was in extreme drought, with a quarter of the state experiencing exceptional drought. The drought caused major damage to crops, particularly in the southern third of the state.

On average, Indiana has experienced wet springs and summers over the past two decades (Figure 2d). While precipitation during these critical growth months is important for adequate soil moisture, it can also make it difficult for farmers to plant crops. Indiana has also experienced an increase in the number of heavy precipitation events (more than 2 inches of precipitation) (Figure 5), which can cause severe flooding. The Great Flood of 1913 was the worst flood in Indiana history. Heavy rains fell from March 23 to 26, causing many rivers across the state to reach flood stage. More than 100 people were killed, with damages estimated at $25 million (in 1913 dollars). Heavy rains on saturated ground were also responsible for severe flooding in June 2008. From June 6 to 7, heavy rain fell across central and southern Indiana, with some stations reporting up to 10 inches of rain. Many streams reached record flood levels. In total, 39 counties were declared disaster areas and damages were estimated at hundreds of millions of dollars. In the summer of 2015, central Indiana experienced historic levels of rainfall characterized by the wettest July on record at Indianapolis (8.6 inches above normal). Flooding in June and July exceeded flood control capacity in three reservoirs for the first time since they were built in the late 1960s. The extremity of this event rivals in magnitude the exceptional drought that impacted the state in 2012, highlighting the extremes in climate that the state has experienced in recent years.

 

Observed Number of Extreme Precipitation Events

Observed Number of Extreme Precipitation Events

Figure 5: The observed number of days with extreme precipitation events (annual number of days with precipitation above 2 inches) for 1900–2014, averaged over 5-year periods; these values are averages from 21 available long-term reporting stations. The dark horizontal line represents the long-term average. A typical station experiences between 1 and 2 such events per year. The number of extreme precipitation events has been above average since the late 1980s. Between 2005 and 2009, Indiana experienced a record high number of events when stations averaged almost 3 events annually. Source: CICS-NC and NOAA NCEI.

Water levels in the Great Lakes have fluctuated over a range of three to six feet since the late 19th century (Figure 6). Higher lake levels were generally noted in the latter part of the 19th century and early 20th century, the 1940s, 1950s, and 1980s. Lower lake levels were observed in the 1920s and 1930s and again in the 1960s. Overall, Lake Michigan-Huron has shown a statistically significant downward trend over the past 150 years. The trend is largely due to the high levels early in the period and the extremely low levels in the past 10 years. However, rapid increases in water levels have been observed in the Great Lakes following historic lows in 2013. In fact, Lakes Michigan and Huron have experienced a remarkable recovery with a rise of more than 3 feet from low levels in 2013. This unexpectedly rapid rise in water levels have been associated with negative impacts along lakeshore areas during high wind and wave events, including beach erosion and damage to piers and other structures built during “low” water years.

Annual Lake-Wide Average Water Levels for Lake Michigan-Huron

Annual Lake-Wide Average Water Levels for Lake Michigan-Huron

Figure 6: Annual time series of the water level of Lake Michigan-Huron. Water levels in the Great Lakes have varied widely over the years. Lake Michigan-Huron has shown a statistically significant downward trend over the past 150 years. The trend is largely due to the high levels early in the period and extremely low levels during the 21st century. Source: NOAA NOS and Canadian Hydrographic Service.

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 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. If the warming trend continues, future heat waves are likely to be more intense. Extreme heat is of particular concern for Indianapolis and other urban areas where high temperatures, combined with high humidity, can cause dangerous heat index values, a phenomenon known as the urban heat island effect. By contrast, the intensity of cold waves is projected to decrease.

Precipitation is projected to increase in Indiana, with increases most likely during the winter and spring (Figure 7). Extreme precipitation is also projected to increase, potentially increasing the frequency and intensity of floods. Heavier precipitation not only increases the risk of springtime flooding, but also poses a threat to Indiana’s important agricultural economy by delaying planting and resulting in loss of yield.
 

 

Projected Change in Spring Precipitation

Projected Change in Spring Precipitation

Figure 7: Projected change in spring precipitation (%) for 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. Spring precipitation is projected to increase in the range of 10-20% by 2050. Source: CICS-NC, NOAA NCEI, and NEMAC.

The intensity of future droughts is projected to increase. Even if precipitation increases in the future, increases in temperature will increase evaporation rates and the rate of loss of soil moisture. Thus, future summer droughts, a natural part of the Indiana climate, are likely to be more intense.

Lead Authors:
Rebekah Frankson and Kenneth E. Kunkel
Contributing Authors:
Sarah Champion, Brooke C. Stewart, and Jennifer Runkle
Recommended Citation:
Frankson, R., K. Kunkel, S. Champion, B. Stewart, and J. Runkle, 2017: Indiana State Summary. NOAA Technical Report NESDIS 149-IN, 4 pp.

Resources

  1. Changnon, S.A. and D. Changnon, 2005: The pre-Christmas 2004 snowstorm disaster in the Ohio River Valley, Illinois State Water Survey, Center for Atmospheric Science, Contract Report 2005-03, 26 pp. [Available online at http://www.isws.illinois.edu/pubdoc/CR/ISWSCR2005-03.pdf]
  2. Indiana Geological Survey, cited 2016: Geologic hazards - Flooding in Indiana: Not “If”, but “When”. [Available online at http://igs.indiana.edu/Hazards/Flooding.cfm]
  3. Indiana Historical Bureau, cited 2016: Tri-state tornado. [Available online at http://www.in.gov/history/markers/16.htm]
  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. Morlock, S.E., C.D. Menke, D.V. Arvin, and M.H. Kim, 2008: Flood of June 7–9, 2008, in central and southern Indiana: U.S. Geological Survey Open File Report 2008–1322, 15 p., 3 app. [Available online at http://pubs.usgs.gov/of/2008/1322/pdf/ofr2008-1322.pdf]
  6. NOAA, 2008: 2008 Midwestern U.S. floods, National Oceanic and Atmospheric Administration National Climatic Data Center, 10pp. [Available online at ftp.ncdc.noaa.gov/pub/data/extremeevents/specialreports/2008-Midwestern-US-Floods.pdf]
  7. NOAA, 2014: Water levels of the Great Lakes, National Oceanic and Atmospheric Administration.[Available online at http://www.glerl.noaa.gov/pubs/brochures/lakelevels/lakelevels_09_2014.pdf]
  8. NOAA, 2015: National - Significant Events for June-August 2015, Quarterly Climate Impacts and Outlook, Midwest Region, 2pp, National Oceanic and Atmospheric Administration. [Available online at http://mrcc.isws.illinois.edu/pubs/docs/RC_Midwest_201509Sept_Final.pdf]
  9. NOAA, cited 2016: Climate at a Glance: U.S. Time Series, published December 2016, retrieved on December 19, 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 Indiana, National Oceanic and Atmospheric Administration. [Available online at https://www.ncdc.noaa.gov/climatenormals/clim60/states/Clim_IN_01.pdf]
  11. NOAA, cited 2016: State of the Climate: National Snow and Ice for January 2014, published online February 2014, retrieved on December 19, 2016, National Oceanic and Atmospheric Administration National Centers for Environmental Information. [Available online at http://www.ncdc.noaa.gov/sotc/snow/201401]
  12. NOAA, cited 2016: Winter Storm, December 22-23, 2004, National Oceanic and Atmospheric Administration. [Available online at http://www.crh.noaa.gov/Image/lmk/pdf/dec2004snow.pdf]
  13. NOAA, cited 2016. The Easter Freeze of April 2017: A Climatological Perspective and Assessment of Impacts and Services, Technical Report 2008-01, A NOAA/USDA technical report, 56 pp, National Oceanic and Atmospheric Administration, United States Department of Agriculture. [Available online at http://www1.ncdc.noaa.gov/pub/data/techrpts/tr200801/tech-report-200801.pdf]
  14. NWS, cited 2016: 1925 Tornado: NOAA/NWS 1925 tri-state tornado website--Tornado track, National Oceanic and Atmospheric Administration National Weather Service. [Available online at http://www.weather.gov/pah/1925Tornado_tt]
  15. NWS, cited 2016: April 11th 1965 Palm Sunday tornado outbreak, National Oceanic and Atmospheric Administration National Weather Service. [Available online at http://www.weather.gov/iwx/1965_palmsunday_50]
  16. NWS, cited 2016: Flooding in Indiana, National Oceanic and Atmospheric Administration National Weather Service. [Available online at http://www.floodsafety.noaa.gov/states/in-flood.shtml]
  17. NWS, cited 2016: June 2, 1990 tornado outbreak, National Oceanic and Atmospheric Administration National Weather Service. [Available online at http://www.weather.gov/ind/june2_1990tor]
  18. United States Drought Monitor, cited 2016: Maps and Data. [Available online at http://droughtmonitor.unl.edu/MapsAndData.aspx]
  19. Weather.gov, cited 2016: Central Indiana July 2015 Climate Summary, 4pp. [Available online at http://www.weather.gov/media/ind/climate/July2015.pdf]
 
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