Koolau Dam 833 Weather Records (USC00514766)
Record envelope, standing records and threshold days for Koolau Dam 833 (USC00514766), Hawaii, United States, with 81 years of record.
Key Facts for Koolau Dam 833
- Koolau Dam 833 (USC00514766) is a weather station in Hawaii, United States at 21.50 latitude and -157.97 longitude, 354 m (1,160 ft) above sea level.
- The station reports from 1919 to 1999, 81 years of record.
- 0 records set at Koolau Dam 833 still stand.
- Records are tracked for prcp, snow, snwd: an element needs 30 years of data to be eligible.
- Koolau Dam 833 set a daily record precipitation of 58.4 mm (2.3 in) on 26 October 1993.
About the Station
- Location: Hawaii, United States, 21.50 latitude, -157.97 longitude.
- Elevation: 354 m (1,160 ft).
- Period of record: 1919 to 1999, 81 years.
- Eligible elements: prcp, snow, snwd.
Daily Record Envelope and 2026
0 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | n/a | n/a | n/a | n/a |
| Feb | n/a | n/a | n/a | n/a |
| Mar | n/a | n/a | n/a | n/a |
| Apr | n/a | n/a | n/a | n/a |
| May | n/a | n/a | n/a | n/a |
| Jun | n/a | n/a | n/a | n/a |
| Jul | n/a | n/a | n/a | n/a |
| Aug | n/a | n/a | n/a | n/a |
| Sep | n/a | n/a | n/a | n/a |
| Oct | n/a | n/a | n/a | n/a |
| Nov | n/a | n/a | n/a | n/a |
| Dec | n/a | n/a | n/a | n/a |
Which Years Hold Standing Records
0 standing records| Year set | Standing records |
|---|
All-Time Record Progression
1 new records| Date | Kind | Detail |
|---|---|---|
| 1954-11-29 | Record daily precipitation | Record daily precipitation 335.3 mm (13.2 in) |
Wettest Day of Each Month
Nov: 335.3 mm (13.2 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 188.0 mm (7.4 in) | 5 January 1988 |
| Feb | 222.3 mm (8.8 in) | 27 February 1935 |
| Mar | 241.3 mm (9.5 in) | 19 March 1980 |
| Apr | 218.4 mm (8.6 in) | 19 April 1977 |
| May | 152.4 mm (6.0 in) | 6 May 1986 |
| Jun | 122.4 mm (4.8 in) | 12 June 1986 |
| Jul | 198.1 mm (7.8 in) | 26 July 1970 |
| Aug | 135.9 mm (5.4 in) | 7 August 1983 |
| Sep | 126.5 mm (5.0 in) | 9 September 1986 |
| Oct | 217.7 mm (8.6 in) | 28 October 1981 |
| Nov | 335.3 mm (13.2 in) | 29 November 1954 |
| Dec | 152.9 mm (6.0 in) | 25 December 1927 |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 26 October 1993 | Koolau Dam 833, US | daily rain | 58.4 mm (2.3 in) | 1.2 mm (0.05 in) | 46 years | 20 of 100 (Routine) |
| 13 September 1990 | Koolau Dam 833, US | daily rain | 42.4 mm (1.7 in) | 10.6 mm (0.4 in) | 41 years | 27 of 100 (Routine) |
| 1 August 1989 | Koolau Dam 833, US | daily rain | 88.4 mm (3.5 in) | 18.0 mm (0.7 in) | 4 years | 21 of 100 (Routine) |
| 4 April 1989 | Koolau Dam 833, US | daily rain | 99.6 mm (3.9 in) | 27.2 mm (1.1 in) | 26 years | 29 of 100 (Routine) |
| 11 July 1988 | Koolau Dam 833, US | daily rain | 85.3 mm (3.4 in) | 4.0 mm (0.16 in) | 34 years | 19 of 100 (Routine) |
| 5 April 1988 | Koolau Dam 833, US | daily rain | 132.3 mm (5.2 in) | 71.3 mm (2.8 in) | 14 years | 51 of 100 (Notable) |
| 5 January 1988 | Koolau Dam 833, US | monthly rain | 188.0 mm (7.4 in) | 2.6 mm (0.10 in) | 37 years | 29 of 100 (Routine) |
| 7 July 1987 | Koolau Dam 833, US | daily rain | 105.2 mm (4.1 in) | 54.4 mm (2.1 in) | 4 years | 43 of 100 (Notable) |
| 2 December 1986 | Koolau Dam 833, US | daily rain | 73.7 mm (2.9 in) | 19.1 mm (0.8 in) | 32 years | 25 of 100 (Routine) |
| 9 September 1986 | Koolau Dam 833, US | monthly rain | 126.5 mm (5.0 in) | 15.2 mm (0.6 in) | 63 years | 47 of 100 (Notable) |
| 8 July 1986 | Koolau Dam 833, US | daily rain | 95.3 mm (3.8 in) | 11.2 mm (0.4 in) | 15 years | 17 of 100 (Routine) |
| 12 June 1986 | Koolau Dam 833, US | monthly rain | 122.4 mm (4.8 in) | 18.3 mm (0.7 in) | 52 years | 46 of 100 (Notable) |
| 6 May 1986 | Koolau Dam 833, US | monthly rain | 152.4 mm (6.0 in) | 2.5 mm (0.10 in) | 20 years | 23 of 100 (Routine) |
| 3 December 1985 | Koolau Dam 833, US | daily rain | 58.4 mm (2.3 in) | 19.0 mm (0.7 in) | 8 years | 18 of 100 (Routine) |
| 1 August 1985 | Koolau Dam 833, US | daily rain | 70.4 mm (2.8 in) | 28.7 mm (1.1 in) | 55 years | 43 of 100 (Notable) |
| 4 March 1985 | Koolau Dam 833, US | daily rain | 132.1 mm (5.2 in) | 81.3 mm (3.2 in) | 40 years | 56 of 100 (Notable) |
| 27 April 1984 | Koolau Dam 833, US | daily rain | 39.1 mm (1.5 in) | 2.0 mm (0.08 in) | 35 years | 17 of 100 (Routine) |
| 16 February 1984 | Koolau Dam 833, US | daily rain | 43.9 mm (1.7 in) | 7.6 mm (0.30 in) | 56 years | 26 of 100 (Routine) |
| 4 October 1983 | Koolau Dam 833, US | daily rain | 160.0 mm (6.3 in) | 107.9 mm (4.2 in) | 10 years | 49 of 100 (Notable) |
| 7 August 1983 | Koolau Dam 833, US | monthly rain | 135.9 mm (5.4 in) | 0.8 mm (0.03 in) | 0 years | 16 of 100 (Routine) |
Extremes by Year
1919 to 1999| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Wettest day (Rx1day) | 335.3 mm (13.2 in) | 1954 | 117.5 mm (4.6 in) | 80 |
| Wettest five days (Rx5day) | 447.8 mm (17.6 in) | 1980 | 224.0 mm (8.8 in) | 79 |
| Longest dry spell (CDD) | 22 days | 1931 | 9 days | 80 |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1919 | 108.0 mm (4.3 in) |
| 1920 | 135.9 mm (5.4 in) |
| 1921 | 121.9 mm (4.8 in) |
| 1922 | 166.4 mm (6.6 in) |
| 1923 | 118.6 mm (4.7 in) |
| 1924 | 146.1 mm (5.8 in) |
| 1925 | 86.9 mm (3.4 in) |
| 1926 | 77.2 mm (3.0 in) |
| 1927 | 152.9 mm (6.0 in) |
| 1928 | 73.9 mm (2.9 in) |
| 1929 | 77.5 mm (3.1 in) |
| 1930 | 128.3 mm (5.1 in) |
| 1931 | 51.8 mm (2.0 in) |
| 1932 | 160.5 mm (6.3 in) |
| 1933 | 116.3 mm (4.6 in) |
| 1934 | 78.7 mm (3.1 in) |
| 1935 | 222.3 mm (8.8 in) |
| 1936 | 139.2 mm (5.5 in) |
| 1937 | 65.8 mm (2.6 in) |
| 1938 | 61.7 mm (2.4 in) |
| 1939 | 90.9 mm (3.6 in) |
| 1940 | 141.2 mm (5.6 in) |
| 1941 | 84.3 mm (3.3 in) |
| 1942 | 85.9 mm (3.4 in) |
| 1943 | 100.3 mm (3.9 in) |
| 1944 | 55.9 mm (2.2 in) |
| 1945 | 182.9 mm (7.2 in) |
| 1946 | 116.8 mm (4.6 in) |
| 1947 | 93.5 mm (3.7 in) |
| 1948 | 111.5 mm (4.4 in) |
| 1949 | 183.9 mm (7.2 in) |
| 1950 | 185.4 mm (7.3 in) |
| 1951 | 130.0 mm (5.1 in) |
| 1952 | 96.5 mm (3.8 in) |
| 1953 | 102.4 mm (4.0 in) |
| 1954 | 335.3 mm (13.2 in) |
| 1955 | 127.8 mm (5.0 in) |
| 1956 | 84.6 mm (3.3 in) |
| 1957 | 118.9 mm (4.7 in) |
| 1958 | 220.5 mm (8.7 in) |
| 1959 | 109.2 mm (4.3 in) |
| 1960 | 97.8 mm (3.9 in) |
| 1961 | 103.1 mm (4.1 in) |
| 1962 | 131.6 mm (5.2 in) |
| 1963 | 118.1 mm (4.6 in) |
| 1964 | 89.4 mm (3.5 in) |
| 1965 | 162.6 mm (6.4 in) |
| 1966 | 175.3 mm (6.9 in) |
| 1967 | 100.1 mm (3.9 in) |
| 1968 | 206.2 mm (8.1 in) |
| 1969 | 206.8 mm (8.1 in) |
| 1970 | 198.1 mm (7.8 in) |
| 1971 | 119.4 mm (4.7 in) |
| 1972 | 95.3 mm (3.8 in) |
| 1973 | 103.6 mm (4.1 in) |
| 1974 | 178.3 mm (7.0 in) |
| 1975 | 125.2 mm (4.9 in) |
| 1976 | 114.3 mm (4.5 in) |
| 1977 | 218.4 mm (8.6 in) |
| 1978 | 119.9 mm (4.7 in) |
| 1979 | 147.3 mm (5.8 in) |
| 1980 | 241.3 mm (9.5 in) |
| 1981 | 217.7 mm (8.6 in) |
| 1982 | 152.4 mm (6.0 in) |
| 1983 | 160.0 mm (6.3 in) |
| 1984 | 53.3 mm (2.1 in) |
| 1985 | 132.1 mm (5.2 in) |
| 1986 | 152.4 mm (6.0 in) |
| 1987 | 105.2 mm (4.1 in) |
| 1988 | 188.0 mm (7.4 in) |
| 1989 | 118.1 mm (4.6 in) |
| 1990 | 71.1 mm (2.8 in) |
| 1991 | 6.1 mm (0.24 in) |
| 1992 | 0.8 mm (0.03 in) |
| 1993 | 58.4 mm (2.3 in) |
| 1994 | 0.0 mm (0.00 in) |
| 1995 | 11.4 mm (0.4 in) |
| 1996 | 4.8 mm (0.19 in) |
| 1997 | 0.0 mm (0.00 in) |
| 1998 | 0.0 mm (0.00 in) |
| 1999 | n/a |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1919 | 168.7 mm (6.6 in) |
| 1920 | 260.8 mm (10.3 in) |
| 1921 | 292.1 mm (11.5 in) |
| 1922 | 305.1 mm (12.0 in) |
| 1923 | 293.3 mm (11.5 in) |
| 1924 | 219.5 mm (8.6 in) |
| 1925 | 163.1 mm (6.4 in) |
| 1926 | 133.1 mm (5.2 in) |
| 1927 | 242.8 mm (9.6 in) |
| 1928 | 209.5 mm (8.2 in) |
| 1929 | 160.6 mm (6.3 in) |
| 1930 | 174.5 mm (6.9 in) |
| 1931 | 94.4 mm (3.7 in) |
| 1932 | 274.8 mm (10.8 in) |
| 1933 | 224.0 mm (8.8 in) |
| 1934 | 133.5 mm (5.3 in) |
| 1935 | 327.1 mm (12.9 in) |
| 1936 | 281.9 mm (11.1 in) |
| 1937 | 287.0 mm (11.3 in) |
| 1938 | 123.7 mm (4.9 in) |
| 1939 | 228.0 mm (9.0 in) |
| 1940 | 150.6 mm (5.9 in) |
| 1941 | 182.7 mm (7.2 in) |
| 1942 | 115.6 mm (4.6 in) |
| 1943 | 149.1 mm (5.9 in) |
| 1944 | 111.8 mm (4.4 in) |
| 1945 | 308.6 mm (12.1 in) |
| 1946 | 256.9 mm (10.1 in) |
| 1947 | 226.8 mm (8.9 in) |
| 1948 | 242.1 mm (9.5 in) |
| 1949 | 320.5 mm (12.6 in) |
| 1950 | 256.2 mm (10.1 in) |
| 1951 | 257.4 mm (10.1 in) |
| 1952 | 174.8 mm (6.9 in) |
| 1953 | 167.2 mm (6.6 in) |
| 1954 | 411.4 mm (16.2 in) |
| 1955 | 262.9 mm (10.4 in) |
| 1956 | 163.9 mm (6.5 in) |
| 1957 | 285.8 mm (11.3 in) |
| 1958 | 294.6 mm (11.6 in) |
| 1959 | 199.0 mm (7.8 in) |
| 1960 | 169.9 mm (6.7 in) |
| 1961 | 201.1 mm (7.9 in) |
| 1962 | 183.1 mm (7.2 in) |
| 1963 | 315.9 mm (12.4 in) |
| 1964 | 225.3 mm (8.9 in) |
| 1965 | 424.0 mm (16.7 in) |
| 1966 | 311.1 mm (12.2 in) |
| 1967 | 244.7 mm (9.6 in) |
| 1968 | 224.6 mm (8.8 in) |
| 1969 | 345.0 mm (13.6 in) |
| 1970 | 272.0 mm (10.7 in) |
| 1971 | 280.2 mm (11.0 in) |
| 1972 | 199.8 mm (7.9 in) |
| 1973 | 224.4 mm (8.8 in) |
| 1974 | 413.1 mm (16.3 in) |
| 1975 | 376.5 mm (14.8 in) |
| 1976 | 331.9 mm (13.1 in) |
| 1977 | 257.3 mm (10.1 in) |
| 1978 | 305.3 mm (12.0 in) |
| 1979 | 197.9 mm (7.8 in) |
| 1980 | 447.8 mm (17.6 in) |
| 1981 | 299.5 mm (11.8 in) |
| 1982 | 260.1 mm (10.2 in) |
| 1983 | 5.6 mm (0.22 in) |
| 1984 | 133.8 mm (5.3 in) |
| 1985 | 0.8 mm (0.03 in) |
| 1986 | 0.0 mm (0.00 in) |
| 1987 | n/a |
| 1988 | 90.4 mm (3.6 in) |
| 1989 | 14.2 mm (0.6 in) |
| 1990 | 0.0 mm (0.00 in) |
| 1991 | 0.0 mm (0.00 in) |
| 1992 | 0.0 mm (0.00 in) |
| 1993 | 58.4 mm (2.3 in) |
| 1994 | 0.0 mm (0.00 in) |
| 1995 | 0.0 mm (0.00 in) |
| 1996 | 0.0 mm (0.00 in) |
| 1997 | 0.0 mm (0.00 in) |
| 1998 | 0.0 mm (0.00 in) |
| 1999 | n/a |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1919 | 13 days |
| 1920 | 11 days |
| 1921 | 11 days |
| 1922 | 9 days |
| 1923 | 9 days |
| 1924 | 19 days |
| 1925 | 14 days |
| 1926 | 12 days |
| 1927 | 12 days |
| 1928 | 17 days |
| 1929 | 15 days |
| 1930 | 8 days |
| 1931 | 22 days |
| 1932 | 6 days |
| 1933 | 17 days |
| 1934 | 11 days |
| 1935 | 11 days |
| 1936 | 10 days |
| 1937 | 9 days |
| 1938 | 6 days |
| 1939 | 5 days |
| 1940 | 18 days |
| 1941 | 16 days |
| 1942 | 20 days |
| 1943 | 7 days |
| 1944 | 20 days |
| 1945 | 10 days |
| 1946 | 13 days |
| 1947 | 14 days |
| 1948 | 10 days |
| 1949 | 7 days |
| 1950 | 8 days |
| 1951 | 10 days |
| 1952 | 14 days |
| 1953 | 8 days |
| 1954 | 12 days |
| 1955 | 8 days |
| 1956 | 9 days |
| 1957 | 17 days |
| 1958 | 9 days |
| 1959 | 15 days |
| 1960 | 7 days |
| 1961 | 10 days |
| 1962 | 12 days |
| 1963 | 10 days |
| 1964 | 8 days |
| 1965 | 8 days |
| 1966 | 10 days |
| 1967 | 8 days |
| 1968 | 9 days |
| 1969 | 8 days |
| 1970 | 3 days |
| 1971 | 4 days |
| 1972 | 8 days |
| 1973 | 13 days |
| 1974 | 8 days |
| 1975 | 11 days |
| 1976 | 6 days |
| 1977 | 8 days |
| 1978 | 13 days |
| 1979 | 10 days |
| 1980 | 8 days |
| 1981 | 9 days |
| 1982 | 7 days |
| 1983 | 12 days |
| 1984 | 13 days |
| 1985 | 7 days |
| 1986 | 7 days |
| 1987 | 2 days |
| 1988 | 5 days |
| 1989 | 8 days |
| 1990 | 9 days |
| 1991 | 5 days |
| 1992 | 9 days |
| 1993 | 6 days |
| 1994 | 7 days |
| 1995 | 5 days |
| 1996 | 7 days |
| 1997 | 7 days |
| 1998 | 7 days |
| 1999 | n/a |
Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.
Rainfall Return Levels
54 years, 1919 to 1981A day with at least 120.5 mm (4.7 in) of rain is expected about once in 2 years. A day with at least 328.3 mm (12.9 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 120.5 mm (4.7 in) | |
| 5 years | 167.8 mm (6.6 in) | |
| 10 years | 202.2 mm (8.0 in) | |
| 25 years | 249.5 mm (9.8 in) | |
| 50 years | 287.7 mm (11.3 in) | |
| 100 years | 328.3 mm (12.9 in) | Longer than the 54 years of record |
The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 54 years of values from 1919 to 1981.
A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.
The largest wettest-day totals in the fit: 335.3 mm (13.2 in) in 1954; 241.3 mm (9.5 in) in 1980; 222.3 mm (8.8 in) in 1935.
Download the Data
Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-13 (13 October 2026). Records are computed by this site and are not official.
Data as of . Last revised (2025-12-31).