Haleakala Exp Farm 434 Weather Records (USC00510995)

Record envelope, standing records and threshold days for Haleakala Exp Farm 434 (USC00510995), Hawaii, United States, with 54 years of record.

Key Facts for Haleakala Exp Farm 434

Haleakala Exp Farm 434 (USC00510995) is a weather station in Hawaii, United States at 20.85 latitude and -156.30 longitude, 640 m (2,100 ft) above sea level.
The station reports from 1939 to 1992, 54 years of record.
1,464 records set at Haleakala Exp Farm 434 still stand.
Records are tracked for prcp, snow, snwd: an element needs 30 years of data to be eligible.
Haleakala Exp Farm 434 set a daily record precipitation of 10.9 mm (0.4 in) on 17 June 1992.

About the Station

Location: Hawaii, United States, 20.85 latitude, -156.30 longitude.
Elevation: 640 m (2,100 ft).
Period of record: 1939 to 1992, 54 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 Haleakala Exp Farm 434. 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 Haleakala Exp Farm 434, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	26.1 C (79.0 F)	8.3 C (46.9 F)	n/a	n/a
Feb	26.7 C (80.1 F)	6.7 C (44.1 F)	n/a	n/a
Mar	25.0 C (77.0 F)	8.9 C (48.0 F)	n/a	n/a
Apr	26.7 C (80.1 F)	9.4 C (48.9 F)	n/a	n/a
May	30.0 C (86.0 F)	10.6 C (51.1 F)	n/a	n/a
Jun	30.0 C (86.0 F)	8.3 C (46.9 F)	n/a	n/a
Jul	27.8 C (82.0 F)	12.8 C (55.0 F)	n/a	n/a
Aug	27.8 C (82.0 F)	11.1 C (52.0 F)	n/a	n/a
Sep	30.0 C (86.0 F)	12.2 C (54.0 F)	n/a	n/a
Oct	28.3 C (82.9 F)	12.2 C (54.0 F)	n/a	n/a
Nov	26.7 C (80.1 F)	10.6 C (51.1 F)	n/a	n/a
Dec	25.6 C (78.1 F)	7.8 C (46.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Haleakala Exp Farm 434 still stand. 1955 holds the most, with 116.

Standing records at Haleakala Exp Farm 434 by the year they were set
Year set	Standing records
1943	65
1944	80
1945	114
1946	94
1947	102
1948	65
1949	89
1950	68
1951	68
1952	66
1953	53
1954	71
1955	116
1956	52
1957	66
1958	88
1959	63
1960	43
1961	43
1962	38
1963	19
1974	1

Wettest Day of Each Month

Nov: 346.2 mm (13.6 in)

The wettest day on record for each calendar month at Haleakala Exp Farm 434. The most was 346.2 mm (13.6 in) on 29 November 1968.

Record daily precipitation for each month at Haleakala Exp Farm 434
Month	Record daily precipitation (mm)	Date
Jan	317.5 mm (12.5 in)	26 January 1948
Feb	241.8 mm (9.5 in)	26 February 1956
Mar	165.6 mm (6.5 in)	7 March 1985
Apr	164.3 mm (6.5 in)	2 April 1961
May	145.0 mm (5.7 in)	15 May 1963
Jun	240.8 mm (9.5 in)	30 June 1941
Jul	72.4 mm (2.9 in)	11 July 1965
Aug	160.5 mm (6.3 in)	8 August 1991
Sep	48.8 mm (1.9 in)	6 September 1941
Oct	176.0 mm (6.9 in)	26 October 1947
Nov	346.2 mm (13.6 in)	29 November 1968
Dec	250.7 mm (9.9 in)	21 December 1946

Period of Record Coverage

1943 to 1974

22 years of record at Haleakala Exp Farm 434, 1943 to 1974. 4 years have data for under 90 percent of days and are left out of rankings: 1943, 1962, 1963, 1974.

Days with data per year at Haleakala Exp Farm 434
Year	Days with data	Share of year	Complete
1943	150	41%	No
1944	364	99%	Yes
1945	365	100%	Yes
1946	365	100%	Yes
1947	362	99%	Yes
1948	362	99%	Yes
1949	364	100%	Yes
1950	359	98%	Yes
1951	351	96%	Yes
1952	362	99%	Yes
1953	361	99%	Yes
1954	363	99%	Yes
1955	364	100%	Yes
1956	366	100%	Yes
1957	364	100%	Yes
1958	361	99%	Yes
1959	358	98%	Yes
1960	360	98%	Yes
1961	357	98%	Yes
1962	254	70%	No
1963	63	17%	No
1974	28	8%	No

Latest Records

Latest records at Haleakala Exp Farm 434
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
17 June 1992	Haleakala Exp Farm 434, US	daily rain	10.9 mm (0.4 in)	0.5 mm (0.02 in)	24 years	12 of 100 (Routine)
5 May 1992	Haleakala Exp Farm 434, US	daily rain	54.4 mm (2.1 in)	11.2 mm (0.4 in)	52 years	28 of 100 (Routine)
11 September 1991	Haleakala Exp Farm 434, US	daily rain	10.9 mm (0.4 in)	0.7 mm (0.03 in)	49 years	19 of 100 (Routine)
27 August 1991	Haleakala Exp Farm 434, US	daily rain	17.8 mm (0.7 in)	7.9 mm (0.31 in)	48 years	20 of 100 (Routine)
8 August 1991	Haleakala Exp Farm 434, US	monthly rain	160.5 mm (6.3 in)	45.9 mm (1.8 in)	9 years	50 of 100 (Notable)
5 June 1991	Haleakala Exp Farm 434, US	daily rain	20.3 mm (0.8 in)	4.0 mm (0.16 in)	38 years	19 of 100 (Routine)
29 May 1991	Haleakala Exp Farm 434, US	daily rain	22.9 mm (0.9 in)	11.5 mm (0.5 in)	50 years	20 of 100 (Routine)
12 March 1991	Haleakala Exp Farm 434, US	daily rain	96.8 mm (3.8 in)	36.1 mm (1.4 in)	13 years	26 of 100 (Routine)
11 October 1990	Haleakala Exp Farm 434, US	daily rain	56.4 mm (2.2 in)	36.1 mm (1.4 in)	49 years	41 of 100 (Notable)
1 October 1990	Haleakala Exp Farm 434, US	daily rain	61.0 mm (2.4 in)	38.1 mm (1.5 in)	4 years	30 of 100 (Routine)
19 September 1990	Haleakala Exp Farm 434, US	daily rain	27.4 mm (1.1 in)	8.1 mm (0.32 in)	48 years	29 of 100 (Routine)
19 June 1990	Haleakala Exp Farm 434, US	daily rain	28.7 mm (1.1 in)	8.9 mm (0.35 in)	48 years	26 of 100 (Routine)
15 June 1990	Haleakala Exp Farm 434, US	daily rain	14.5 mm (0.6 in)	6.1 mm (0.24 in)	36 years	20 of 100 (Routine)
2 March 1990	Haleakala Exp Farm 434, US	daily rain	69.6 mm (2.7 in)	42.2 mm (1.7 in)	8 years	26 of 100 (Routine)
1 February 1990	Haleakala Exp Farm 434, US	daily rain	51.3 mm (2.0 in)	8.1 mm (0.32 in)	14 years	12 of 100 (Routine)
2 January 1990	Haleakala Exp Farm 434, US	daily rain	135.4 mm (5.3 in)	89.4 mm (3.5 in)	48 years	51 of 100 (Notable)
19 July 1989	Haleakala Exp Farm 434, US	daily rain	18.8 mm (0.7 in)	4.6 mm (0.18 in)	8 years	11 of 100 (Routine)
6 July 1989	Haleakala Exp Farm 434, US	daily rain	48.0 mm (1.9 in)	0.5 mm (0.02 in)	20 years	11 of 100 (Routine)
2 June 1989	Haleakala Exp Farm 434, US	daily rain	20.3 mm (0.8 in)	4.0 mm (0.16 in)	22 years	14 of 100 (Routine)
14 April 1989	Haleakala Exp Farm 434, US	daily rain	153.2 mm (6.0 in)	102.9 mm (4.1 in)	44 years	58 of 100 (Notable)

Climate Trend

17 complete years, 1944 to 1961

One stripe for each of 17 complete years at Haleakala Exp Farm 434, 1944 to 1961. Blue stripes are years cooler than the station's own mean of 18.8 C (65.8 F); red stripes are warmer. The coolest year was 1955, at 17.9 C (64.3 F), and the warmest was 1945, at 19.3 C (66.7 F). The strongest colour marks a difference of 0.9 C (1.6 F).

Annual mean temperature at Haleakala Exp Farm 434 as warming stripes, 1944 to 1961
Year	Annual mean temperature	Difference from the station mean
1944	18.9 C	+0.14 C
1945	19.3 C	+0.50 C
1946	19.1 C	+0.28 C
1947	19.0 C	+0.23 C
1948	18.7 C	-0.07 C
1949	18.3 C	-0.51 C
1950	18.7 C	-0.11 C
1952	18.4 C	-0.36 C
1953	19.0 C	+0.24 C
1954	19.0 C	+0.19 C
1955	17.9 C	-0.83 C
1956	18.7 C	-0.12 C
1957	18.7 C	-0.04 C
1958	18.5 C	-0.28 C
1959	19.0 C	+0.22 C
1960	18.8 C	+0.05 C
1961	19.2 C	+0.41 C

This station does not have enough complete years (30 are needed) to fit a temperature trend.

A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.

Extremes by Year

1939 to 1992

Yearly extremes at Haleakala Exp Farm 434: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	30.0 C (86.0 F)	1947	27.2 C (81.0 F)	22
Coldest night (TNn)	6.7 C (44.1 F)	1951	8.9 C (48.0 F)	22
Wettest day (Rx1day)	346.2 mm (13.6 in)	1968	118.8 mm (4.7 in)	54
Wettest five days (Rx5day)	629.5 mm (24.8 in)	1948	196.9 mm (7.8 in)	54
Longest dry spell (CDD)	46 days	1953	17 days	54

Hottest day (TXx)

The hottest day of the year at Haleakala Exp Farm 434, 1939 to 1992. The record is 30.0 C (86.0 F) in 1947, marked on the chart; the median year is 27.2 C (81.0 F).

Hottest day (TXx) at Haleakala Exp Farm 434 by year
Year	Hottest day (TXx)
1939	n/a
1940	n/a
1941	n/a
1942	n/a
1943	27.8 C (82.0 F)
1944	27.2 C (81.0 F)
1945	26.7 C (80.1 F)
1946	29.4 C (84.9 F)
1947	30.0 C (86.0 F)
1948	26.7 C (80.1 F)
1949	26.1 C (79.0 F)
1950	26.7 C (80.1 F)
1951	27.8 C (82.0 F)
1952	27.2 C (81.0 F)
1953	28.3 C (82.9 F)
1954	26.7 C (80.1 F)
1955	26.7 C (80.1 F)
1956	26.1 C (79.0 F)
1957	27.2 C (81.0 F)
1958	26.7 C (80.1 F)
1959	30.0 C (86.0 F)
1960	27.8 C (82.0 F)
1961	28.3 C (82.9 F)
1962	27.2 C (81.0 F)
1963	24.4 C (75.9 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	22.8 C (73.0 F)
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

Coldest night (TNn)

The coldest night of the year at Haleakala Exp Farm 434, 1939 to 1992. The record is 6.7 C (44.1 F) in 1951, marked on the chart; the median year is 8.9 C (48.0 F).

Coldest night (TNn) at Haleakala Exp Farm 434 by year
Year	Coldest night (TNn)
1939	n/a
1940	n/a
1941	n/a
1942	n/a
1943	11.1 C (52.0 F)
1944	9.4 C (48.9 F)
1945	8.9 C (48.0 F)
1946	8.9 C (48.0 F)
1947	8.9 C (48.0 F)
1948	8.9 C (48.0 F)
1949	8.9 C (48.0 F)
1950	8.9 C (48.0 F)
1951	6.7 C (44.1 F)
1952	9.4 C (48.9 F)
1953	10.0 C (50.0 F)
1954	7.8 C (46.0 F)
1955	9.4 C (48.9 F)
1956	8.3 C (46.9 F)
1957	10.0 C (50.0 F)
1958	8.9 C (48.0 F)
1959	10.0 C (50.0 F)
1960	7.8 C (46.0 F)
1961	9.4 C (48.9 F)
1962	8.9 C (48.0 F)
1963	8.9 C (48.0 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	11.7 C (53.1 F)
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

Wettest day (Rx1day)

The wettest day of the year at Haleakala Exp Farm 434, 1939 to 1992. The record is 346.2 mm (13.6 in) in 1968, marked on the chart; the median year is 118.8 mm (4.7 in).

Wettest day (Rx1day) at Haleakala Exp Farm 434 by year
Year	Wettest day (Rx1day)
1939	102.9 mm (4.1 in)
1940	105.7 mm (4.2 in)
1941	240.8 mm (9.5 in)
1942	137.2 mm (5.4 in)
1943	58.4 mm (2.3 in)
1944	96.5 mm (3.8 in)
1945	64.0 mm (2.5 in)
1946	250.7 mm (9.9 in)
1947	176.0 mm (6.9 in)
1948	317.5 mm (12.5 in)
1949	97.8 mm (3.9 in)
1950	105.9 mm (4.2 in)
1951	74.9 mm (2.9 in)
1952	72.4 mm (2.9 in)
1953	89.2 mm (3.5 in)
1954	92.5 mm (3.6 in)
1955	109.0 mm (4.3 in)
1956	241.8 mm (9.5 in)
1957	104.6 mm (4.1 in)
1958	64.3 mm (2.5 in)
1959	144.8 mm (5.7 in)
1960	165.1 mm (6.5 in)
1961	164.3 mm (6.5 in)
1962	85.3 mm (3.4 in)
1963	145.0 mm (5.7 in)
1964	120.9 mm (4.8 in)
1965	125.5 mm (4.9 in)
1966	72.1 mm (2.8 in)
1967	105.9 mm (4.2 in)
1968	346.2 mm (13.6 in)
1969	227.3 mm (8.9 in)
1970	109.2 mm (4.3 in)
1971	111.8 mm (4.4 in)
1972	82.0 mm (3.2 in)
1973	132.1 mm (5.2 in)
1974	123.2 mm (4.9 in)
1975	49.8 mm (2.0 in)
1976	102.4 mm (4.0 in)
1977	84.6 mm (3.3 in)
1978	120.7 mm (4.8 in)
1979	148.6 mm (5.9 in)
1980	155.2 mm (6.1 in)
1981	128.0 mm (5.0 in)
1982	183.6 mm (7.2 in)
1983	82.3 mm (3.2 in)
1984	116.8 mm (4.6 in)
1985	165.6 mm (6.5 in)
1986	106.9 mm (4.2 in)
1987	123.2 mm (4.9 in)
1988	170.2 mm (6.7 in)
1989	153.2 mm (6.0 in)
1990	135.4 mm (5.3 in)
1991	160.5 mm (6.3 in)
1992	54.4 mm (2.1 in)

Wettest five days (Rx5day)

The wettest five days of the year at Haleakala Exp Farm 434, 1939 to 1992. The record is 629.5 mm (24.8 in) in 1948, marked on the chart; the median year is 196.9 mm (7.8 in).

Wettest five days (Rx5day) at Haleakala Exp Farm 434 by year
Year	Wettest five days (Rx5day)
1939	156.5 mm (6.2 in)
1940	193.3 mm (7.6 in)
1941	268.5 mm (10.6 in)
1942	431.9 mm (17.0 in)
1943	122.4 mm (4.8 in)
1944	132.5 mm (5.2 in)
1945	153.1 mm (6.0 in)
1946	607.3 mm (23.9 in)
1947	201.7 mm (7.9 in)
1948	629.5 mm (24.8 in)
1949	108.9 mm (4.3 in)
1950	204.0 mm (8.0 in)
1951	139.1 mm (5.5 in)
1952	146.3 mm (5.8 in)
1953	179.3 mm (7.1 in)
1954	358.7 mm (14.1 in)
1955	267.5 mm (10.5 in)
1956	367.6 mm (14.5 in)
1957	191.2 mm (7.5 in)
1958	137.6 mm (5.4 in)
1959	216.8 mm (8.5 in)
1960	414.0 mm (16.3 in)
1961	266.9 mm (10.5 in)
1962	131.5 mm (5.2 in)
1963	170.2 mm (6.7 in)
1964	306.6 mm (12.1 in)
1965	200.4 mm (7.9 in)
1966	170.9 mm (6.7 in)
1967	207.7 mm (8.2 in)
1968	370.8 mm (14.6 in)
1969	388.8 mm (15.3 in)
1970	301.2 mm (11.9 in)
1971	157.0 mm (6.2 in)
1972	151.1 mm (5.9 in)
1973	193.3 mm (7.6 in)
1974	216.2 mm (8.5 in)
1975	128.7 mm (5.1 in)
1976	134.4 mm (5.3 in)
1977	230.6 mm (9.1 in)
1978	283.7 mm (11.2 in)
1979	429.8 mm (16.9 in)
1980	465.1 mm (18.3 in)
1981	249.9 mm (9.8 in)
1982	435.9 mm (17.2 in)
1983	116.0 mm (4.6 in)
1984	143.7 mm (5.7 in)
1985	376.0 mm (14.8 in)
1986	314.9 mm (12.4 in)
1987	103.4 mm (4.1 in)
1988	189.2 mm (7.4 in)
1989	98.0 mm (3.9 in)
1990	111.6 mm (4.4 in)
1991	43.1 mm (1.7 in)
1992	97.0 mm (3.8 in)

Longest dry spell (CDD)

The longest dry spell of the year at Haleakala Exp Farm 434, 1939 to 1992. The record is 46 days in 1953, marked on the chart; the median year is 17 days.

Longest dry spell (CDD) at Haleakala Exp Farm 434 by year
Year	Longest dry spell (CDD)
1939	11 days
1940	15 days
1941	16 days
1942	21 days
1943	25 days
1944	25 days
1945	31 days
1946	43 days
1947	26 days
1948	12 days
1949	20 days
1950	23 days
1951	20 days
1952	15 days
1953	46 days
1954	18 days
1955	22 days
1956	14 days
1957	30 days
1958	11 days
1959	22 days
1960	13 days
1961	14 days
1962	27 days
1963	13 days
1964	10 days
1965	15 days
1966	15 days
1967	14 days
1968	17 days
1969	11 days
1970	14 days
1971	27 days
1972	21 days
1973	18 days
1974	33 days
1975	25 days
1976	14 days
1977	18 days
1978	10 days
1979	17 days
1980	15 days
1981	20 days
1982	13 days
1983	19 days
1984	27 days
1985	22 days
1986	15 days
1987	8 days
1988	10 days
1989	18 days
1990	7 days
1991	10 days
1992	11 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

41 years, 1940 to 1984

A day with at least 116.6 mm (4.6 in) of rain is expected about once in 2 years. A day with at least 408.9 mm (16.1 in) of rain is expected about once in 100 years.

Rainfall return levels at Haleakala Exp Farm 434: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	116.6 mm (4.6 in)
5 years	172.7 mm (6.8 in)
10 years	217.4 mm (8.6 in)
25 years	284.2 mm (11.2 in)
50 years	342.5 mm (13.5 in)	Longer than the 41 years of record
100 years	408.9 mm (16.1 in)	Longer than the 41 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, 41 years of values from 1940 to 1984.

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: 346.2 mm (13.6 in) in 1968; 317.5 mm (12.5 in) in 1948; 250.7 mm (9.9 in) in 1946.

Download the Data

Data for Haleakala Exp Farm 434 standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Haleakala Exp Farm 434 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 2026-10-14 (14 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).