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What were Oklahoma's worst recent drought and wet years?

Reviewed by Preston, Oklahoma foundation repair consultant · Updated 2026-10-14

In short: Oklahoma swung from one of its worst droughts, covering nearly the whole state in 2011 and 2012, to its wettest month on record in May 2015. Another severe drought in 2022 dried soils to at least 32 inches deep. These swings drive the shrinking and swelling of clay under foundations.

Why does weather history matter for foundations?

Oklahoma's expansive clays shrink as they dry and swell as they wet. The upper layer that responds to weather, called the active zone, is estimated at about 0.5 to 4 meters (1.6 to 13 feet) deep across the state, and the shallowest soil responds most strongly to climate 5. Long droughts tend to show up as settlement, especially at the edges of a house, while sudden wet periods after drought can cause heave (upward movement). See drought and wet cycles and heave vs settlement.

What were Oklahoma's historic drought and wet periods?

The U.S. Geological Survey identifies four major 20th-century drought periods in Oklahoma by water year: 1929 to 1941, 1952 to 1956, 1961 to 1972 and 1976 to 1981 8.

Period What the records show
1910 Driest year on record statewide: 19.04 inches 6
1950 to 1956 Driest seven-year period of the century, averaging 28.51 inches a year; 1952 to 1956 averaged 25.81 inches 7
May 1957 Heavy rains ended the drought with major flooding on the Cimarron, Arkansas and Canadian rivers; 1957 became the wettest year of the century at the time 7
June to July 2007 13.14 inches statewide, the wettest June-July on record since 1895 9
October 2010 to September 2014 34 of 48 months drier than normal, with a statewide deficit of over 30 inches 10
Summer 2011 Warmest June-August on record statewide, averaging 86.9°F 6
2015 Wettest year on record: 53.88 inches (preliminary), 17.38 inches above normal 11
March 2018 Exceptional drought (D4) jumped from 0% to 15% of the state, in the far northwest and Panhandle 12
May 2019 10.48 inches statewide, third-wettest May since 1895; the Arkansas River crested near or above record levels and Tulsa had its worst flooding since 1986 13
Mid-October 2022 Extreme and exceptional drought (D3 to D4) reached 86% of the state 14

What were the recent weather extremes?

Period What the records show
August 2011 93% of Oklahoma in extreme to exceptional drought (D3 to D4), with 65% exceptional (D4) 1
August 2012 About 97% in D3 to D4, the highest coverage since the U.S. Drought Monitor began in 2000; D4 at 16% 1
May 1 to early August 2012 Statewide rain averaged 5.87 inches, 7.03 inches below normal, second driest such period since 1921 1
Start of May 2015 59% of Oklahoma in drought after about five years of drought 2
May 2015 Wettest month ever for Oklahoma: 14.40 inches statewide, 9.58 inches above normal 2
End of May 2015 Drought coverage fell to 3%, the lowest since October 2010 2
September 2022 Critically dry soils to at least 32 inches; 64% of the state in D3 to D4 and 94% in D2 or worse 3

Drought levels come from the U.S. Drought Monitor: D2 is severe, D3 extreme, and D4 exceptional.

The 2011 to 2012 drought

By August 2012, the Mesonet reported 63 days without a daily rain of at least 0.10 inch at its Norman site, and the January through July 2012 statewide average temperature of 63.7°F was on pace to challenge the 1954 record 1. North-central Oklahoma had its driest May-to-early-August period since 1921, with 3.95 inches 1.

May 2015 and 2019: drought to flood

May 2015 broke the previous statewide monthly record of 10.75 inches set in October 1941 2. Local totals were higher still:

The rains nearly ended a drought that had lasted about five years 2, and 2015 went on to become Oklahoma's wettest year on record 11. In May 2019, statewide rain of 10.48 inches pushed the Arkansas River near or above record levels from the Kansas line to the Arkansas line, and flooding in Tulsa was the worst since 1986 13. See creeks and flood history.

After years of drying, a sudden soaking like this can rewet clay along the perimeter of a house first; see perimeter wetting heave and over-lift heave after drought lift.

2022

From the September 2022 summary: the Mesonet measured critically dry soils down to at least 32 inches, and severe-or-worse drought covered about 94% of the state on September 27 3. By mid-October, extreme to exceptional drought covered 86% of the state 14. Deep drying like this is associated with perimeter drying settlement.

How much water does Oklahoma lose to evaporation?

Evaporation pulls water out of exposed soil and water surfaces during the warm season. OSU Extension fact sheet BAE-1529 reports average May to October evaporation from shallow water bodies 4:

Region (climate division) May to October evaporation
Panhandle (CD-1) 44.4 inches 4
West central and southwest (CD-4, CD-7) 40.9 and 40.3 inches 4
Northeast (CD-3) 30.1 inches 4
Southeast (CD-9) 28.1 inches 4

Losses increase from east to west and can be higher in drought years 4. Higher evaporation in western Oklahoma means soils there face stronger drying than in the east.

Free, plain-English answers. It asks a few questions and walks you to the repair that fits.

Common questions

What was the wettest month in Oklahoma history?

May 2015, when the statewide average was 14.40 inches, beating the old record of 10.75 inches from October 1941. Oklahoma City received 19.48 inches that month.

How bad was the 2011 to 2012 drought in Oklahoma?

In August 2011, 93% of Oklahoma was in extreme or exceptional drought, including 65% in exceptional drought. In August 2012, about 97% of the state was in extreme or exceptional drought.

How dry was the soil in the 2022 drought?

The Oklahoma Mesonet measured critically dry soils down to at least 32 inches in September 2022, when about 94% of the state was in severe drought or worse.

Does Oklahoma lose more water to evaporation than it gets in rain?

Evaporation is high. OSU Extension reports May to October evaporation from shallow water of about 28 to 30 inches in eastern Oklahoma and about 40 to 44 inches in the southwest, west central and Panhandle divisions.

What was Oklahoma's worst drought on record?

The 1950s drought stands out: 1950 to 1956 was the driest seven-year period of the 20th century, averaging 28.51 inches of rain a year statewide, and it ended with major flooding in May 1957.

What was Oklahoma's wettest year?

2015, with a preliminary statewide total of 53.88 inches, breaking the 1957 record of 47.88 inches.

Sources

  1. Extreme to Exceptional Drought Covers Most of Oklahoma Oklahoma Mesonet
  2. Oklahoma Monthly Climate Summary, May 2015 Oklahoma Climatological Survey
  3. Oklahoma Monthly Climate Summary, September 2022 Oklahoma Climatological Survey
  4. Evaporation Losses from Shallow Water Bodies in Oklahoma (BAE-1529) Oklahoma State University Extension
  5. Soil matric suction and active zone depth in Oklahoma Oklahoma State University (SHAREOK repository)
  6. Oklahoma State Climate Records Oklahoma Climatological Survey
  7. Oklahoma Weather Timeline: 1950-1959 Oklahoma Climatological Survey
  8. Hydrologic Drought of Water Year 2006 Compared with Four Major Drought Periods of the 20th Century in Oklahoma (SIR 2008-5199) U.S. Geological Survey
  9. Oklahoma Monthly Climate Summary, July 2007 Oklahoma Climatological Survey
  10. Oklahoma Monthly Climate Summary, September 2014 Oklahoma Climatological Survey
  11. Oklahoma Monthly Climate Summary, December 2015 Oklahoma Climatological Survey
  12. Oklahoma Monthly Climate Summary, March 2018 Oklahoma Climatological Survey
  13. Oklahoma Monthly Climate Summary, May 2019 Oklahoma Climatological Survey
  14. Oklahoma Monthly Climate Summary, October 2022 Oklahoma Climatological Survey

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