Mahinahina 466 Weather Records (USC00515715)

Record envelope, standing records and threshold days for Mahinahina 466 (USC00515715), Hawaii, United States, with 107 years of record.

Key Facts for Mahinahina 466

Mahinahina 466 (USC00515715) is a weather station in Hawaii, United States at 20.96 latitude and -156.65 longitude, 257 m (842 ft) above sea level.
The station reports from 1919 to 2025, 107 years of record.
1,464 records set at Mahinahina 466 still stand.
Records are tracked for prcp, snow, snwd: an element needs 30 years of data to be eligible.
Mahinahina 466 set a daily record precipitation of 14.7 mm (0.6 in) on 13 July 2025.

About the Station

Location: Hawaii, United States, 20.96 latitude, -156.65 longitude.
Elevation: 257 m (842 ft).
Period of record: 1919 to 2025, 107 years.
Eligible elements: prcp, snow, snwd.

Daily Record Envelope and 2026

0 days at or beyond a record

The band shows the record high and record low for each calendar day at Mahinahina 466. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at Mahinahina 466, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	27.8 C (82.0 F)	12.8 C (55.0 F)	n/a	n/a
Feb	29.4 C (84.9 F)	11.7 C (53.1 F)	n/a	n/a
Mar	28.9 C (84.0 F)	11.7 C (53.1 F)	n/a	n/a
Apr	29.4 C (84.9 F)	12.8 C (55.0 F)	n/a	n/a
May	31.1 C (88.0 F)	15.0 C (59.0 F)	n/a	n/a
Jun	30.0 C (86.0 F)	15.0 C (59.0 F)	n/a	n/a
Jul	30.6 C (87.1 F)	15.0 C (59.0 F)	n/a	n/a
Aug	31.1 C (88.0 F)	17.8 C (64.0 F)	n/a	n/a
Sep	31.7 C (89.1 F)	15.6 C (60.1 F)	n/a	n/a
Oct	31.1 C (88.0 F)	15.0 C (59.0 F)	n/a	n/a
Nov	31.1 C (88.0 F)	15.6 C (60.1 F)	n/a	n/a
Dec	30.6 C (87.1 F)	12.2 C (54.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Mahinahina 466 still stand. 1957 holds the most, with 246.

Wettest Day of Each Month

Jan: 240.0 mm (9.4 in)

The wettest day on record for each calendar month at Mahinahina 466. The most was 240.0 mm (9.4 in) on 14 January 1923.

Record daily precipitation for each month at Mahinahina 466
Month	Record daily precipitation (mm)	Date
Jan	240.0 mm (9.4 in)	14 January 1923
Feb	167.6 mm (6.6 in)	5 February 1937
Mar	229.9 mm (9.1 in)	14 March 1951
Apr	146.3 mm (5.8 in)	9 April 1938
May	111.8 mm (4.4 in)	6 May 1987
Jun	45.7 mm (1.8 in)	11 June 1926
Jul	93.5 mm (3.7 in)	23 July 1993
Aug	185.4 mm (7.3 in)	2 August 1982
Sep	78.7 mm (3.1 in)	26 September 1924
Oct	104.1 mm (4.1 in)	18 October 1985
Nov	200.7 mm (7.9 in)	18 November 1930
Dec	233.9 mm (9.2 in)	25 December 1927

Period of Record Coverage

1942 to 1963

9 years of record at Mahinahina 466, 1942 to 1963. 9 years have data for under 90 percent of days and are left out of rankings: 1942, 1956, 1957, 1958, 1959, 1960, 1961, 1962 and others.

Latest Records

Latest records at Mahinahina 466
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
13 July 2025	Mahinahina 466, US	daily rain	14.7 mm (0.6 in)	2.0 mm (0.08 in)	8 years	14 of 100 (Routine)
18 June 2025	Mahinahina 466, US	daily rain	22.9 mm (0.9 in)	5.6 mm (0.22 in)	95 years	20 of 100 (Routine)
2 September 2024	Mahinahina 466, US	daily rain	24.1 mm (0.9 in)	4.8 mm (0.19 in)	26 years	20 of 100 (Routine)
15 April 2024	Mahinahina 466, US	daily rain	53.3 mm (2.1 in)	13.7 mm (0.5 in)	9 years	22 of 100 (Routine)
19 July 2023	Mahinahina 466, US	daily rain	34.3 mm (1.4 in)	17.5 mm (0.7 in)	101 years	63 of 100 (Major)
13 June 2022	Mahinahina 466, US	daily rain (Tie)	11.4 mm (0.4 in)	tie	9 years	3 of 100 (Routine)
2 May 2022	Mahinahina 466, US	daily rain	49.8 mm (2.0 in)	29.0 mm (1.1 in)	7 years	46 of 100 (Notable)
29 October 2020	Mahinahina 466, US	daily rain	45.2 mm (1.8 in)	15.7 mm (0.6 in)	55 years	39 of 100 (Notable)
4 January 2020	Mahinahina 466, US	daily rain	53.3 mm (2.1 in)	3.8 mm (0.15 in)	97 years	40 of 100 (Notable)
3 October 2019	Mahinahina 466, US	daily rain	27.2 mm (1.1 in)	4.3 mm (0.17 in)	29 years	21 of 100 (Routine)
1 July 2019	Mahinahina 466, US	daily rain	25.1 mm (1.0 in)	3.3 mm (0.13 in)	80 years	38 of 100 (Notable)
18 May 2019	Mahinahina 466, US	daily rain	26.9 mm (1.1 in)	2.8 mm (0.11 in)	52 years	28 of 100 (Routine)
14 February 2019	Mahinahina 466, US	daily rain	57.2 mm (2.3 in)	23.9 mm (0.9 in)	95 years	53 of 100 (Notable)
20 October 2018	Mahinahina 466, US	daily rain	23.4 mm (0.9 in)	8.7 mm (0.34 in)	35 years	20 of 100 (Routine)
29 September 2018	Mahinahina 466, US	daily rain	26.2 mm (1.0 in)	2.8 mm (0.11 in)	87 years	39 of 100 (Notable)
28 September 2018	Mahinahina 466, US	daily rain	52.8 mm (2.1 in)	14.7 mm (0.6 in)	79 years	51 of 100 (Notable)
13 September 2018	Mahinahina 466, US	daily rain	54.4 mm (2.1 in)	43.0 mm (1.7 in)	91 years	77 of 100 (Major)
12 September 2018	Mahinahina 466, US	daily rain	50.8 mm (2.0 in)	30.0 mm (1.2 in)	95 years	75 of 100 (Major)
27 August 2018	Mahinahina 466, US	daily rain	46.2 mm (1.8 in)	30.2 mm (1.2 in)	20 years	45 of 100 (Notable)
8 July 2018	Mahinahina 466, US	daily rain	36.6 mm (1.4 in)	17.0 mm (0.7 in)	51 years	47 of 100 (Notable)

Extremes by Year

1919 to 2025

Yearly extremes at Mahinahina 466: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	31.7 C (89.1 F)	1959	30.6 C (87.1 F)	9
Coldest night (TNn)	11.7 C (53.1 F)	1942	12.8 C (55.0 F)	9
Wettest day (Rx1day)	240.0 mm (9.4 in)	1923	86.9 mm (3.4 in)	107
Wettest five days (Rx5day)	351.0 mm (13.8 in)	1923	137.6 mm (5.4 in)	107
Longest dry spell (CDD)	53 days	1977	18 days	107

Hottest day (TXx)

The hottest day of the year at Mahinahina 466, 1919 to 2025. The record is 31.7 C (89.1 F) in 1959, marked on the chart; the median year is 30.6 C (87.1 F).

Hottest day (TXx) at Mahinahina 466 by year
Year	Hottest day (TXx)
1919	n/a
1920	n/a
1921	n/a
1922	n/a
1923	n/a
1924	n/a
1925	n/a
1926	n/a
1927	n/a
1928	n/a
1929	n/a
1930	n/a
1931	n/a
1932	n/a
1933	n/a
1934	n/a
1935	n/a
1936	n/a
1937	n/a
1938	n/a
1939	n/a
1940	n/a
1941	n/a
1942	30.6 C (87.1 F)
1943	n/a
1944	n/a
1945	n/a
1946	n/a
1947	n/a
1948	n/a
1949	n/a
1950	n/a
1951	n/a
1952	n/a
1953	n/a
1954	n/a
1955	n/a
1956	28.9 C (84.0 F)
1957	30.6 C (87.1 F)
1958	30.6 C (87.1 F)
1959	31.7 C (89.1 F)
1960	31.1 C (88.0 F)
1961	31.1 C (88.0 F)
1962	31.1 C (88.0 F)
1963	28.9 C (84.0 F)
1964	n/a
1965	n/a
1966	n/a
1967	n/a
1968	n/a
1969	n/a
1970	n/a
1971	n/a
1972	n/a
1973	n/a
1974	n/a
1975	n/a
1976	n/a
1977	n/a
1978	n/a
1979	n/a
1980	n/a
1981	n/a
1982	n/a
1983	n/a
1984	n/a
1985	n/a
1986	n/a
1987	n/a
1988	n/a
1989	n/a
1990	n/a
1991	n/a
1992	n/a
1993	n/a
1994	n/a
1995	n/a
1996	n/a
1997	n/a
1998	n/a
1999	n/a
2000	n/a
2001	n/a
2002	n/a
2003	n/a
2004	n/a
2005	n/a
2006	n/a
2007	n/a
2008	n/a
2009	n/a
2010	n/a
2011	n/a
2012	n/a
2013	n/a
2014	n/a
2015	n/a
2016	n/a
2017	n/a
2018	n/a
2019	n/a
2020	n/a
2021	n/a
2022	n/a
2023	n/a
2024	n/a
2025	n/a

Coldest night (TNn)

The coldest night of the year at Mahinahina 466, 1919 to 2025. The record is 11.7 C (53.1 F) in 1942, marked on the chart; the median year is 12.8 C (55.0 F).

Coldest night (TNn) at Mahinahina 466 by year
Year	Coldest night (TNn)
1919	n/a
1920	n/a
1921	n/a
1922	n/a
1923	n/a
1924	n/a
1925	n/a
1926	n/a
1927	n/a
1928	n/a
1929	n/a
1930	n/a
1931	n/a
1932	n/a
1933	n/a
1934	n/a
1935	n/a
1936	n/a
1937	n/a
1938	n/a
1939	n/a
1940	n/a
1941	n/a
1942	11.7 C (53.1 F)
1943	n/a
1944	n/a
1945	n/a
1946	n/a
1947	n/a
1948	n/a
1949	n/a
1950	n/a
1951	n/a
1952	n/a
1953	n/a
1954	n/a
1955	n/a
1956	14.4 C (57.9 F)
1957	12.2 C (54.0 F)
1958	12.8 C (55.0 F)
1959	13.9 C (57.0 F)
1960	12.8 C (55.0 F)
1961	13.3 C (55.9 F)
1962	11.7 C (53.1 F)
1963	12.8 C (55.0 F)
1964	n/a
1965	n/a
1966	n/a
1967	n/a
1968	n/a
1969	n/a
1970	n/a
1971	n/a
1972	n/a
1973	n/a
1974	n/a
1975	n/a
1976	n/a
1977	n/a
1978	n/a
1979	n/a
1980	n/a
1981	n/a
1982	n/a
1983	n/a
1984	n/a
1985	n/a
1986	n/a
1987	n/a
1988	n/a
1989	n/a
1990	n/a
1991	n/a
1992	n/a
1993	n/a
1994	n/a
1995	n/a
1996	n/a
1997	n/a
1998	n/a
1999	n/a
2000	n/a
2001	n/a
2002	n/a
2003	n/a
2004	n/a
2005	n/a
2006	n/a
2007	n/a
2008	n/a
2009	n/a
2010	n/a
2011	n/a
2012	n/a
2013	n/a
2014	n/a
2015	n/a
2016	n/a
2017	n/a
2018	n/a
2019	n/a
2020	n/a
2021	n/a
2022	n/a
2023	n/a
2024	n/a
2025	n/a

Wettest day (Rx1day)

The wettest day of the year at Mahinahina 466, 1919 to 2025. The record is 240.0 mm (9.4 in) in 1923, marked on the chart; the median year is 86.9 mm (3.4 in).

Wettest day (Rx1day) at Mahinahina 466 by year
Year	Wettest day (Rx1day)
1919	35.3 mm (1.4 in)
1920	87.4 mm (3.4 in)
1921	175.0 mm (6.9 in)
1922	79.0 mm (3.1 in)
1923	240.0 mm (9.4 in)
1924	198.4 mm (7.8 in)
1925	112.0 mm (4.4 in)
1926	110.5 mm (4.4 in)
1927	233.9 mm (9.2 in)
1928	96.5 mm (3.8 in)
1929	134.6 mm (5.3 in)
1930	200.7 mm (7.9 in)
1931	41.1 mm (1.6 in)
1932	96.5 mm (3.8 in)
1933	106.7 mm (4.2 in)
1934	59.7 mm (2.4 in)
1935	53.3 mm (2.1 in)
1936	48.3 mm (1.9 in)
1937	167.6 mm (6.6 in)
1938	146.3 mm (5.8 in)
1939	101.6 mm (4.0 in)
1940	101.6 mm (4.0 in)
1941	76.2 mm (3.0 in)
1942	94.0 mm (3.7 in)
1943	86.9 mm (3.4 in)
1944	83.8 mm (3.3 in)
1945	47.2 mm (1.9 in)
1946	94.7 mm (3.7 in)
1947	46.7 mm (1.8 in)
1948	92.5 mm (3.6 in)
1949	101.1 mm (4.0 in)
1950	122.7 mm (4.8 in)
1951	229.9 mm (9.1 in)
1952	108.0 mm (4.3 in)
1953	53.3 mm (2.1 in)
1954	48.3 mm (1.9 in)
1955	172.2 mm (6.8 in)
1956	72.6 mm (2.9 in)
1957	58.4 mm (2.3 in)
1958	71.4 mm (2.8 in)
1959	114.3 mm (4.5 in)
1960	92.7 mm (3.6 in)
1961	118.6 mm (4.7 in)
1962	95.5 mm (3.8 in)
1963	68.6 mm (2.7 in)
1964	135.9 mm (5.4 in)
1965	99.1 mm (3.9 in)
1966	57.9 mm (2.3 in)
1967	102.9 mm (4.1 in)
1968	103.1 mm (4.1 in)
1969	75.4 mm (3.0 in)
1970	58.4 mm (2.3 in)
1971	81.3 mm (3.2 in)
1972	114.3 mm (4.5 in)
1973	85.9 mm (3.4 in)
1974	94.0 mm (3.7 in)
1975	66.0 mm (2.6 in)
1976	66.0 mm (2.6 in)
1977	103.9 mm (4.1 in)
1978	48.3 mm (1.9 in)
1979	100.3 mm (3.9 in)
1980	119.4 mm (4.7 in)
1981	99.8 mm (3.9 in)
1982	185.4 mm (7.3 in)
1983	168.9 mm (6.6 in)
1984	38.9 mm (1.5 in)
1985	152.4 mm (6.0 in)
1986	55.9 mm (2.2 in)
1987	111.8 mm (4.4 in)
1988	95.0 mm (3.7 in)
1989	77.5 mm (3.1 in)
1990	46.7 mm (1.8 in)
1991	59.7 mm (2.4 in)
1992	48.8 mm (1.9 in)
1993	93.5 mm (3.7 in)
1994	96.5 mm (3.8 in)
1995	20.3 mm (0.8 in)
1996	68.6 mm (2.7 in)
1997	35.6 mm (1.4 in)
1998	27.4 mm (1.1 in)
1999	33.3 mm (1.3 in)
2000	33.0 mm (1.3 in)
2001	5.1 mm (0.20 in)
2002	0.0 mm (0.00 in)
2003	0.0 mm (0.00 in)
2004	88.9 mm (3.5 in)
2005	74.9 mm (2.9 in)
2006	139.2 mm (5.5 in)
2007	118.1 mm (4.6 in)
2008	53.3 mm (2.1 in)
2009	76.7 mm (3.0 in)
2010	117.6 mm (4.6 in)
2011	97.8 mm (3.9 in)
2012	71.9 mm (2.8 in)
2013	97.3 mm (3.8 in)
2014	90.7 mm (3.6 in)
2015	98.3 mm (3.9 in)
2016	57.2 mm (2.3 in)
2017	57.2 mm (2.3 in)
2018	62.2 mm (2.4 in)
2019	60.2 mm (2.4 in)
2020	53.8 mm (2.1 in)
2021	57.2 mm (2.3 in)
2022	49.8 mm (2.0 in)
2023	41.7 mm (1.6 in)
2024	54.6 mm (2.1 in)
2025	50.8 mm (2.0 in)

Wettest five days (Rx5day)

The wettest five days of the year at Mahinahina 466, 1919 to 2025. The record is 351.0 mm (13.8 in) in 1923, marked on the chart; the median year is 137.6 mm (5.4 in).

Wettest five days (Rx5day) at Mahinahina 466 by year
Year	Wettest five days (Rx5day)
1919	53.3 mm (2.1 in)
1920	126.5 mm (5.0 in)
1921	238.7 mm (9.4 in)
1922	226.0 mm (8.9 in)
1923	351.0 mm (13.8 in)
1924	310.9 mm (12.2 in)
1925	206.5 mm (8.1 in)
1926	119.9 mm (4.7 in)
1927	316.7 mm (12.5 in)
1928	169.2 mm (6.7 in)
1929	232.6 mm (9.2 in)
1930	283.8 mm (11.2 in)
1931	73.2 mm (2.9 in)
1932	182.7 mm (7.2 in)
1933	262.2 mm (10.3 in)
1934	95.0 mm (3.7 in)
1935	86.0 mm (3.4 in)
1936	98.6 mm (3.9 in)
1937	285.8 mm (11.3 in)
1938	345.0 mm (13.6 in)
1939	195.1 mm (7.7 in)
1940	120.6 mm (4.7 in)
1941	151.4 mm (6.0 in)
1942	263.6 mm (10.4 in)
1943	131.3 mm (5.2 in)
1944	130.5 mm (5.1 in)
1945	119.3 mm (4.7 in)
1946	303.5 mm (11.9 in)
1947	112.2 mm (4.4 in)
1948	284.8 mm (11.2 in)
1949	154.6 mm (6.1 in)
1950	190.1 mm (7.5 in)
1951	253.2 mm (10.0 in)
1952	115.6 mm (4.6 in)
1953	77.4 mm (3.0 in)
1954	110.8 mm (4.4 in)
1955	310.9 mm (12.2 in)
1956	98.8 mm (3.9 in)
1957	117.8 mm (4.6 in)
1958	121.9 mm (4.8 in)
1959	189.5 mm (7.5 in)
1960	137.6 mm (5.4 in)
1961	165.6 mm (6.5 in)
1962	122.2 mm (4.8 in)
1963	113.3 mm (4.5 in)
1964	204.7 mm (8.1 in)
1965	244.9 mm (9.6 in)
1966	85.4 mm (3.4 in)
1967	147.6 mm (5.8 in)
1968	232.7 mm (9.2 in)
1969	166.2 mm (6.5 in)
1970	137.8 mm (5.4 in)
1971	152.4 mm (6.0 in)
1972	136.9 mm (5.4 in)
1973	148.6 mm (5.9 in)
1974	150.0 mm (5.9 in)
1975	84.1 mm (3.3 in)
1976	109.5 mm (4.3 in)
1977	227.1 mm (8.9 in)
1978	126.5 mm (5.0 in)
1979	185.9 mm (7.3 in)
1980	213.4 mm (8.4 in)
1981	99.8 mm (3.9 in)
1982	219.7 mm (8.6 in)
1983	168.9 mm (6.6 in)
1984	47.0 mm (1.9 in)
1985	152.4 mm (6.0 in)
1986	71.1 mm (2.8 in)
1987	62.3 mm (2.5 in)
1988	79.5 mm (3.1 in)
1989	183.9 mm (7.2 in)
1990	67.0 mm (2.6 in)
1991	46.2 mm (1.8 in)
1992	47.5 mm (1.9 in)
1993	49.8 mm (2.0 in)
1994	20.9 mm (0.8 in)
1995	39.4 mm (1.6 in)
1996	33.8 mm (1.3 in)
1997	35.6 mm (1.4 in)
1998	29.2 mm (1.1 in)
1999	19.1 mm (0.8 in)
2000	30.5 mm (1.2 in)
2001	0.0 mm (0.00 in)
2002	0.0 mm (0.00 in)
2003	0.0 mm (0.00 in)
2004	149.1 mm (5.9 in)
2005	213.1 mm (8.4 in)
2006	194.3 mm (7.6 in)
2007	301.5 mm (11.9 in)
2008	154.9 mm (6.1 in)
2009	104.8 mm (4.1 in)
2010	253.0 mm (10.0 in)
2011	148.1 mm (5.8 in)
2012	153.0 mm (6.0 in)
2013	205.8 mm (8.1 in)
2014	146.5 mm (5.8 in)
2015	138.6 mm (5.5 in)
2016	117.7 mm (4.6 in)
2017	123.2 mm (4.9 in)
2018	139.2 mm (5.5 in)
2019	182.7 mm (7.2 in)
2020	125.2 mm (4.9 in)
2021	134.1 mm (5.3 in)
2022	78.5 mm (3.1 in)
2023	56.8 mm (2.2 in)
2024	108.8 mm (4.3 in)
2025	56.1 mm (2.2 in)

Longest dry spell (CDD)

The longest dry spell of the year at Mahinahina 466, 1919 to 2025. The record is 53 days in 1977, marked on the chart; the median year is 18 days.

Longest dry spell (CDD) at Mahinahina 466 by year
Year	Longest dry spell (CDD)
1919	30 days
1920	18 days
1921	18 days
1922	19 days
1923	13 days
1924	20 days
1925	16 days
1926	34 days
1927	14 days
1928	16 days
1929	17 days
1930	13 days
1931	20 days
1932	38 days
1933	21 days
1934	14 days
1935	21 days
1936	20 days
1937	10 days
1938	23 days
1939	13 days
1940	15 days
1941	17 days
1942	15 days
1943	31 days
1944	25 days
1945	43 days
1946	20 days
1947	19 days
1948	17 days
1949	12 days
1950	14 days
1951	18 days
1952	12 days
1953	18 days
1954	17 days
1955	19 days
1956	17 days
1957	19 days
1958	16 days
1959	18 days
1960	16 days
1961	21 days
1962	34 days
1963	14 days
1964	16 days
1965	17 days
1966	20 days
1967	23 days
1968	23 days
1969	15 days
1970	14 days
1971	21 days
1972	31 days
1973	17 days
1974	34 days
1975	25 days
1976	27 days
1977	53 days
1978	19 days
1979	26 days
1980	19 days
1981	28 days
1982	20 days
1983	19 days
1984	25 days
1985	14 days
1986	14 days
1987	15 days
1988	15 days
1989	18 days
1990	14 days
1991	16 days
1992	19 days
1993	10 days
1994	16 days
1995	21 days
1996	49 days
1997	11 days
1998	17 days
1999	30 days
2000	39 days
2001	9 days
2002	7 days
2003	7 days
2004	12 days
2005	19 days
2006	19 days
2007	11 days
2008	19 days
2009	13 days
2010	9 days
2011	14 days
2012	24 days
2013	19 days
2014	10 days
2015	12 days
2016	14 days
2017	14 days
2018	12 days
2019	15 days
2020	10 days
2021	19 days
2022	26 days
2023	20 days
2024	11 days
2025	14 days

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

71 years, 1920 to 2021

A day with at least 88.4 mm (3.5 in) of rain is expected about once in 2 years. A day with at least 248.6 mm (9.8 in) of rain is expected about once in 100 years.

Rainfall return levels at Mahinahina 466: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	88.4 mm (3.5 in)
5 years	123.2 mm (4.9 in)
10 years	149.1 mm (5.9 in)
25 years	185.7 mm (7.3 in)
50 years	215.9 mm (8.5 in)
100 years	248.6 mm (9.8 in)	Longer than the 71 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, 71 years of values from 1920 to 2021.

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: 240.0 mm (9.4 in) in 1923; 233.9 mm (9.2 in) in 1927; 229.9 mm (9.1 in) in 1951.

Download the Data

Data for Mahinahina 466 standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Mahinahina 466 threshold days by year: CSV or JSON. Field meanings are on the data page.

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 2025-12-31. Last revised 31 December 2025 (2025-12-31).

Days with data per year at Mahinahina 466
Year	Days with data	Share of year	Complete
1942	116	32%	No
1956	21	6%	No
1957	255	70%	No
1958	237	65%	No
1959	256	70%	No
1960	255	70%	No
1961	255	70%	No
1962	268	73%	No
1963	87	24%	No