Source- https://www.weather.gov/aprfc/breakupDB?site=271
Source- https://www.weather.gov/aprfc/breakupDB?site=271
For more than a century, residents of Bethel have watched the annual breakup of the Kuskokwim River as one of the defining events of spring. A newly compiled historical dataset spanning from 1924 through 2025 reveals not only when the river broke each year, but also how dramatically breakup conditions have changed over time.
The records document official breakup dates along with other important milestones, including when the ice first moved, when river travel became unsafe for people and vehicles, when the first boats appeared, and when the last ice disappeared from the river system. Together, the data paints a remarkably detailed picture of life along the Kuskokwim and the importance of the river to transportation, subsistence, and daily life in Western Alaska.
Historically, breakup in Bethel most often occurs between early and mid-May. Many years cluster around May 5 through May 15, though the river has shown enormous variability over the decades.
One of the latest recorded breakups occurred in 1964, when the river did not officially break until June 3. In contrast, one of the earliest and most remarkable breakups happened in 2019, when the ice went out on April 12 — nearly two months earlier than the latest year on record.
The dataset also reveals how breakup affects much more than simply the movement of ice. Before breakup, the river serves as a winter road connecting communities by snowmachine and vehicle. As spring approaches, dangerous “shoulder season” conditions emerge when the ice is no longer safe for travel but boats still cannot navigate freely. Dates marking “unsafe person” and “unsafe vehicle” travel help document this hazardous transition period that has long been a part of life along the Kuskokwim.
Several entries also contain notes about unusual breakup conditions. In 2000, observers described a “very mild breakup” with little high water and small ice movement. Other years recorded exceptionally thick ice, including 1999 with measured ice thickness exceeding 50 inches.
The historical record also highlights several interesting patterns and coincidences:
- The earliest recorded breakup was April 12, 2019.
- The latest recorded breakup was June 3, 1964.
- Several years shared the exact same breakup date, especially around the first and second weeks of May.
- The 2010s produced both one of the latest modern breakups (May 29, 2013) and the all-time earliest breakup in 2019, showing how unpredictable spring conditions can still be.
- The 2024 breakup occurred on May 8, almost exactly matching the long-term historical average.
Recent decades appear to show a gradual trend toward earlier breakup dates overall, though large year-to-year swings still occur. The 2020s have continued this pattern, with breakup dates often arriving earlier than many mid-20th century averages. Still, years like 2023 demonstrated that late breakups remain possible, with the river not moving out until May 20.
Beyond weather and climate, the records preserve an important part of regional history. For generations, residents have watched the river closely each spring because breakup affects nearly every aspect of life — transportation, freight movement, fishing preparation, subsistence activities, and travel between communities.
In many ways, the breakup record serves as both a climate archive and a cultural timeline of the Kuskokwim River itself.
Historical Breakup Dates by Frequency
| Breakup Date | Number of Times | Years |
|---|---|---|
| April 12 | 1 | 2019 |
| April 20 | 1 | 2016 |
| April 24 | 1 | 1940 |
| April 26 | 1 | 1926 |
| May 1 | 1 | 1961 |
| May 2 | 6 | 1927, 1993, 1997, 2003, 2004, 2018 |
| May 3 | 3 | 1938, 2007, 2020 |
| May 4 | 2 | 1934, 1979 |
| May 5 | 1 | 2022 |
| May 6 | 9 | 1941, 1953, 1967, 1969, 1990, 1995, 2017, 2021, 2025 |
| May 7 | 5 | 1951, 1954, 1974, 1994, 2021 |
| May 8 | 5 | 1980, 1981, 1991, 2024 |
| May 9 | 3 | 1996, 2005, 2009 |
| May 10 | 1 | 2000 |
| May 11 | 5 | 1928, 1958, 1983, 1988, 1989 |
| May 12 | 4 | 1932, 1942, 1963, 1970 |
| May 13 | 3 | 1984, 2008, 2011 |
| May 14 | 6 | 1929, 1935, 1968, 1973, 1986, 2002 |
| May 15 | 2 | 1931, 2012 |
| May 16 | 4 | 1936, 1943, 2001, 2010 |
| May 17 | 3 | 1930, 1947, 2010 |
| May 18 | 8 | 1948, 1950, 1960, 1975, 1976, 1982, 1987, 1999 |
| May 19 | 1 | 1955 |
| May 20 | 2 | 1937, 2023 |
| May 21 | 1 | 1959 |
| May 22 | 1 | 1945 |
| May 23 | 5 | 1924, 1925, 1972, 1977, 2006 |
| May 24 | 1 | 1992 |
| May 25 | 3 | 1946, 1949, 1985 |
| May 28 | 2 | 1952, 1962 |
| May 29 | 1 | 2013 |
| June 3 | 1 | 1964 |
Most common breakup date: May 6
Earliest breakup: April 12, 2019
Latest breakup: June 3, 1964
Kuskokwim River Breakup Odds Chart
Bethel, Alaska • 1924–2025
Each █ represents approximately 1% probability based on 101 years of records.
| Date | Odds |
|---|---|
| Apr 12 | █ 1% |
| Apr 20 | █ 1% |
| Apr 24 | █ 1% |
| Apr 26 | █ 1% |
| May 1 | █ 1% |
| May 2 | ██████ 6% |
| May 3 | ███ 3% |
| May 4 | ██ 2% |
| May 5 | █ 1% |
| May 6 | █████████ 9% ← Most Common |
| May 7 | █████ 5% |
| May 8 | ████ 4% |
| May 9 | ███ 3% |
| May 10 | █ 1% |
| May 11 | █████ 5% |
| May 12 | ████ 4% |
| May 13 | ███ 3% |
| May 14 | ██████ 6% |
| May 15 | ██ 2% |
| May 16 | ████ 4% |
| May 17 | ██ 2% |
| May 18 | ████████ 8% |
| May 19 | █ 1% |
| May 20 | ██ 2% |
| May 21 | █ 1% |
| May 22 | █ 1% |
| May 23 | █████ 5% |
| May 24 | █ 1% |
| May 25 | ███ 3% |
| May 28 | ██ 2% |
| May 29 | █ 1% |
| Jun 3 | █ 1% |
Probability Windows
| Time Window | Odds |
|---|---|
| Before May 1 | ████ 4% |
| May 1 – May 7 | ███████████████████████████ 27% |
| May 8 – May 14 | ██████████████████████████████ 30% |
| May 15 – May 21 | ███████████████████ 19% |
| May 22 – May 31 | ████████████ 12% |
| June or Later | █ 1% |
Historical Summary
- Peak breakup season: May 6 – May 18
- Highest single-day probability: May 6
- Historically, breakup before May is rare.
- Breakup after May 25 is also uncommon.
- Nearly 60% of all breakups occur between May 1 and May 14.
