Highest listed crest 22.54 ft June 2, 1972; 44,700 cubic feet per second
Flood stage 15.0 ft Major flooding from 18.0 ft
Crests at major 8 15th of 70 gauges in Washington
Most recent flood crest November 17, 2021 15.48 ft, minor flooding Listed crests at the Okanogan River near Tonasket, 1929 to 2024 5 10 15 20 25 ft Flood stage 15.0 ft Major 18.0 ft Jun 10, 1929: 10.16 ft, below flood stage; 8,500 cubic feet per second Jun 9, 1930: 10.06 ft, below flood stage; 8,310 cubic feet per second May 16, 1931: 10.23 ft, below flood stage; 8,480 cubic feet per second May 12, 1932: 11.52 ft, below flood stage; 10,600 cubic feet per second Jun 18, 1933: 15.37 ft, minor flooding; 20,200 cubic feet per second Apr 27, 1934: 18.31 ft, major flooding; 26,600 cubic feet per second Jun 2, 1935: 14.08 ft, action stage; 14,900 cubic feet per second May 16, 1936: 12.60 ft, below flood stage; 11,800 cubic feet per second Jun 5, 1937: 14.16 ft, action stage; 15,100 cubic feet per second May 28, 1938: 16.51 ft, minor flooding; 21,400 cubic feet per second May 17, 1939: 12.35 ft, below flood stage; 11,200 cubic feet per second May 26, 1940: 10.61 ft, below flood stage; 7,540 cubic feet per second May 3, 1941: 9.81 ft, below flood stage; 5,180 cubic feet per second May 28, 1942: 15.78 ft, minor flooding; 18,900 cubic feet per second Jun 11, 1943: 13.41 ft, below flood stage; 13,500 cubic feet per second Jun 3, 1944: 13.43 ft, below flood stage; 10,200 cubic feet per second Jun 2, 1945: 15.74 ft, minor flooding; 18,200 cubic feet per second May 29, 1946: 15.12 ft, minor flooding; 16,900 cubic feet per second May 10, 1947: 13.47 ft, below flood stage; 13,400 cubic feet per second May 31, 1948: 21.79 ft, major flooding; 40,900 cubic feet per second May 17, 1949: 18.05 ft, major flooding; 27,200 cubic feet per second Jun 18, 1950: 18.66 ft, major flooding; 29,600 cubic feet per second May 25, 1951: 16.77 ft, minor flooding; 23,600 cubic feet per second May 21, 1952: 14.04 ft, action stage; 16,200 cubic feet per second Jun 15, 1953: 13.86 ft, below flood stage; 15,800 cubic feet per second May 22, 1954: 15.21 ft, minor flooding; 19,100 cubic feet per second Jun 14, 1955: 18.12 ft, major flooding; 27,600 cubic feet per second May 26, 1956: 17.37 ft, moderate flooding; 25,000 cubic feet per second May 22, 1957: 16.71 ft, minor flooding; 23,600 cubic feet per second May 26, 1958: 13.93 ft, below flood stage; 16,100 cubic feet per second Jun 6, 1959: 15.99 ft, minor flooding; 21,500 cubic feet per second Jun 5, 1960: 13.46 ft, below flood stage; 14,100 cubic feet per second Jun 6, 1961: 16.59 ft, minor flooding; 22,300 cubic feet per second May 30, 1962: 12.50 ft, below flood stage; 12,300 cubic feet per second May 25, 1963: 12.70 ft, below flood stage; 12,700 cubic feet per second Jun 12, 1964: 16.30 ft, minor flooding; 22,100 cubic feet per second Jun 12, 1965: 14.08 ft, action stage; 16,000 cubic feet per second May 11, 1966: 11.21 ft, below flood stage; 9,620 cubic feet per second Jun 6, 1967: 15.82 ft, minor flooding; 20,700 cubic feet per second May 22, 1968: 13.91 ft, below flood stage; 15,600 cubic feet per second May 25, 1969: 14.24 ft, action stage; 16,400 cubic feet per second Jun 5, 1970: 13.42 ft, below flood stage; 14,400 cubic feet per second May 15, 1971: 15.74 ft, minor flooding; 20,500 cubic feet per second Jun 2, 1972: 22.54 ft, major flooding; 44,700 cubic feet per second Jun 19, 1973: 11.75 ft, below flood stage; 10,700 cubic feet per second Jun 19, 1974: 18.79 ft, major flooding; 30,500 cubic feet per second Jun 4, 1975: 14.19 ft, action stage; 16,500 cubic feet per second Jun 9, 1977: 9.80 ft, below flood stage; 6,860 cubic feet per second Jun 8, 1978: 14.69 ft, action stage; 17,800 cubic feet per second May 27, 1979: 11.30 ft, below flood stage; 9,800 cubic feet per second May 7, 1980: 12.81 ft, below flood stage; 13,700 cubic feet per second May 27, 1981: 13.60 ft, below flood stage; 15,700 cubic feet per second Jun 16, 1982: 14.17 ft, action stage; 17,000 cubic feet per second Jun 1, 1983: 16.11 ft, minor flooding; 22,400 cubic feet per second Jun 17, 1984: 14.15 ft, action stage; 16,300 cubic feet per second May 25, 1985: 13.56 ft, below flood stage; 15,600 cubic feet per second Jun 2, 1986: 16.88 ft, minor flooding; 24,900 cubic feet per second May 13, 1987: 13.40 ft, below flood stage; 15,100 cubic feet per second May 15, 1988: 10.55 ft, below flood stage; 13,300 cubic feet per second Jun 7, 1989: 12.57 ft, below flood stage; 13,100 cubic feet per second Jun 12, 1990: 13.76 ft, below flood stage; 16,100 cubic feet per second May 23, 1991: 17.37 ft, moderate flooding; 26,400 cubic feet per second May 9, 1992: 10.45 ft, below flood stage; 8,430 cubic feet per second May 16, 1993: 13.58 ft, below flood stage; 15,600 cubic feet per second May 11, 1994: 11.33 ft, below flood stage; 10,200 cubic feet per second Jun 9, 1996: 15.36 ft, minor flooding; 20,400 cubic feet per second May 18, 1997: 17.80 ft, moderate flooding; 27,700 cubic feet per second May 8, 1998: 13.90 ft, below flood stage; 16,400 cubic feet per second Jun 18, 1999: 14.89 ft, action stage; 19,100 cubic feet per second May 23, 2000: 11.59 ft, below flood stage; 10,800 cubic feet per second May 25, 2001: 10.47 ft, below flood stage; 8,470 cubic feet per second Jun 1, 2002: 14.89 ft, action stage; 19,100 cubic feet per second Jun 1, 2003: 11.22 ft, below flood stage; 10,000 cubic feet per second Oct 22, 2003: 11.34 ft, below flood stage; 10,300 cubic feet per second Jan 25, 2005: 13.70 ft, below flood stage; 6,550 cubic feet per second May 22, 2006: 14.11 ft, action stage; 18,000 cubic feet per second Jun 1, 2007: 12.45 ft, below flood stage; 13,700 cubic feet per second May 22, 2008: 15.10 ft, minor flooding; 20,500 cubic feet per second Jun 1, 2009: 11.70 ft, below flood stage; 11,800 cubic feet per second Jun 4, 2010: 12.42 ft, below flood stage; 13,600 cubic feet per second Jun 11, 2011: 17.62 ft, moderate flooding; 23,300 cubic feet per second May 18, 2012: 15.02 ft, minor flooding; 16,003 cubic feet per second May 15, 2013: 17.15 ft, moderate flooding; 23,079 cubic feet per second May 19, 2014: 15.80 ft, minor flooding; 18,746 cubic feet per second May 25, 2014: 15.83 ft, minor flooding; 18,817 cubic feet per second May 25, 2015: 12.17 ft, below flood stage; 10,600 cubic feet per second Apr 25, 2016: 15.73 ft, minor flooding; 18,500 cubic feet per second May 14, 2017: 15.34 ft, minor flooding; 17,508 cubic feet per second Jun 2, 2017: 17.04 ft, moderate flooding; 22,422 cubic feet per second May 12, 2018: 19.71 ft, major flooding; 32,036 cubic feet per second May 18, 2019: 11.71 ft, below flood stage; 10,900 cubic feet per second Jun 2, 2020: 15.81 ft, minor flooding; 19,900 cubic feet per second Nov 17, 2021: 15.48 ft, minor flooding; 19,000 cubic feet per second Jun 7, 2022: 14.15 ft, action stage; 16,000 cubic feet per second May 7, 2023: 14.38 ft, action stage; 16,800 cubic feet per second May 18, 2024: 10.61 ft, below flood stage; 8,870 cubic feet per second Highest, 22.54 ft, Jun 2, 1972 1940 1960 1980 2000 2020 Crests at or above flood stage, by decade Crests at or above flood stage per decade, Okanogan River near Tonasket 1920s: 0 1930s: 3 1940s: 5 1950s: 7 1960s: 3 1970s: 3 1980s: 2 1990s: 3 2000s: 1 2010s: 9 9 2020s: 2 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s 2020s These are the crests the local National Weather Service office lists for the gauge: the highest on record and recent crests. Lesser floods between them may be missing, so counts by decade are a floor. Categories use today's flood stages. Levees, dams and channel changes since a crest can make old and new stages not directly comparable. 05 Other gauges in Okanogan County Okanogan County: every hazard · River floods across the country · Washington
NOAA National Water Prediction Service, gauge TONW1, retrieved October 30, 2026. Stages in feet on the gauge's own datum, not elevation. Crests are as the National Weather Service lists them; preliminary values may be revised.