Wahiawa Dam 863 Weather Records (USC00518945)

Record envelope, standing records and threshold days for Wahiawa Dam 863 (USC00518945), Hawaii, United States, with 39 years of record.

Key Facts for Wahiawa Dam 863

Wahiawa Dam 863 (USC00518945) is a weather station in Hawaii, United States at 21.50 latitude and -158.05 longitude, 260 m (854 ft) above sea level.
The station reports from 1940 to 1978, 39 years of record.
1,092 records set at Wahiawa Dam 863 still stand.
Records are tracked for prcp: an element needs 30 years of data to be eligible.
Wahiawa Dam 863 set a daily record precipitation of 21.3 mm (0.8 in) on 20 April 1978.

About the Station

Location: Hawaii, United States, 21.50 latitude, -158.05 longitude.
Elevation: 260 m (854 ft).
Period of record: 1940 to 1978, 39 years.
Eligible elements: prcp.

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 Wahiawa Dam 863. 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 Wahiawa Dam 863, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	25.6 C (78.1 F)	10.0 C (50.0 F)	n/a	n/a
Feb	26.1 C (79.0 F)	10.6 C (51.1 F)	n/a	n/a
Mar	26.1 C (79.0 F)	11.1 C (52.0 F)	n/a	n/a
Apr	25.6 C (78.1 F)	11.1 C (52.0 F)	n/a	n/a
May	31.7 C (89.1 F)	13.3 C (55.9 F)	n/a	n/a
Jun	28.9 C (84.0 F)	15.0 C (59.0 F)	n/a	n/a
Jul	30.0 C (86.0 F)	13.3 C (55.9 F)	n/a	n/a
Aug	28.3 C (82.9 F)	17.2 C (63.0 F)	n/a	n/a
Sep	31.1 C (88.0 F)	15.0 C (59.0 F)	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

1,092 standing records

1,092 records at Wahiawa Dam 863 still stand. 1949 holds the most, with 1,092.

Wettest Day of Each Month

Mar: 255.8 mm (10.1 in)

The wettest day on record for each calendar month at Wahiawa Dam 863. The most was 255.8 mm (10.1 in) on 6 March 1958.

Record daily precipitation for each month at Wahiawa Dam 863
Month	Record daily precipitation (mm)	Date
Jan	186.7 mm (7.4 in)	21 January 1957
Feb	115.1 mm (4.5 in)	8 February 1949
Mar	255.8 mm (10.1 in)	6 March 1958
Apr	86.4 mm (3.4 in)	9 April 1945
May	90.4 mm (3.6 in)	15 May 1963
Jun	47.0 mm (1.9 in)	22 June 1951
Jul	77.7 mm (3.1 in)	25 July 1966
Aug	110.7 mm (4.4 in)	7 August 1959
Sep	56.4 mm (2.2 in)	6 September 1974
Oct	112.0 mm (4.4 in)	2 October 1940
Nov	130.8 mm (5.1 in)	25 November 1975
Dec	195.3 mm (7.7 in)	18 December 1949

Period of Record Coverage

1949 to 1949

1 years of record at Wahiawa Dam 863, 1949 to 1949. 1 years have data for under 90 percent of days and are left out of rankings: 1949.

Latest Records

Latest records at Wahiawa Dam 863
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
20 April 1978	Wahiawa Dam 863, US	daily rain	21.3 mm (0.8 in)	1.5 mm (0.06 in)	7 years	6 of 100 (Routine)
29 June 1977	Wahiawa Dam 863, US	daily rain	27.9 mm (1.1 in)	21.8 mm (0.9 in)	16 years	47 of 100 (Notable)
28 June 1977	Wahiawa Dam 863, US	daily rain	14.0 mm (0.6 in)	3.1 mm (0.12 in)	16 years	16 of 100 (Routine)
12 May 1977	Wahiawa Dam 863, US	daily rain	46.7 mm (1.8 in)	11.1 mm (0.4 in)	34 years	28 of 100 (Routine)
11 May 1977	Wahiawa Dam 863, US	daily rain	36.3 mm (1.4 in)	26.1 mm (1.0 in)	20 years	45 of 100 (Notable)
30 March 1977	Wahiawa Dam 863, US	daily rain	24.6 mm (1.0 in)	3.5 mm (0.14 in)	28 years	12 of 100 (Routine)
5 October 1976	Wahiawa Dam 863, US	daily rain	32.5 mm (1.3 in)	25.6 mm (1.0 in)	13 years	26 of 100 (Routine)
19 August 1976	Wahiawa Dam 863, US	daily rain	8.9 mm (0.35 in)	5.3 mm (0.21 in)	27 years	16 of 100 (Routine)
1 April 1976	Wahiawa Dam 863, US	daily rain	16.0 mm (0.6 in)	6.9 mm (0.27 in)	9 years	12 of 100 (Routine)
6 February 1976	Wahiawa Dam 863, US	daily rain	102.1 mm (4.0 in)	75.2 mm (3.0 in)	29 years	51 of 100 (Notable)
26 November 1975	Wahiawa Dam 863, US	daily rain	54.9 mm (2.2 in)	47.0 mm (1.9 in)	12 years	46 of 100 (Notable)
25 November 1975	Wahiawa Dam 863, US	monthly rain	130.8 mm (5.1 in)	34.3 mm (1.4 in)	20 years	50 of 100 (Notable)
22 November 1974	Wahiawa Dam 863, US	daily rain	33.3 mm (1.3 in)	17.0 mm (0.7 in)	9 years	20 of 100 (Routine)
19 September 1974	Wahiawa Dam 863, US	daily rain	18.8 mm (0.7 in)	14.2 mm (0.6 in)	16 years	20 of 100 (Routine)
6 September 1974	Wahiawa Dam 863, US	monthly rain	56.4 mm (2.2 in)	3.3 mm (0.13 in)	2 years	19 of 100 (Routine)
5 September 1974	Wahiawa Dam 863, US	daily rain	16.0 mm (0.6 in)	10.2 mm (0.4 in)	15 years	20 of 100 (Routine)
18 July 1974	Wahiawa Dam 863, US	daily rain	37.8 mm (1.5 in)	26.9 mm (1.1 in)	21 years	49 of 100 (Notable)
1 July 1974	Wahiawa Dam 863, US	daily rain	11.7 mm (0.5 in)	3.1 mm (0.12 in)	11 years	12 of 100 (Routine)
24 June 1974	Wahiawa Dam 863, US	daily rain	5.3 mm (0.21 in)	1.7 mm (0.07 in)	12 years	10 of 100 (Routine)
19 June 1974	Wahiawa Dam 863, US	daily rain	8.6 mm (0.34 in)	1.2 mm (0.05 in)	19 years	11 of 100 (Routine)

Extremes by Year

1940 to 1978

Yearly extremes at Wahiawa Dam 863: 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)	1949	31.7 C (89.1 F)	1
Coldest night (TNn)	10.0 C (50.0 F)	1949	10.0 C (50.0 F)	1
Wettest day (Rx1day)	255.8 mm (10.1 in)	1958	89.2 mm (3.5 in)	39
Wettest five days (Rx5day)	443.3 mm (17.5 in)	1957	113.3 mm (4.5 in)	39
Longest dry spell (CDD)	36 days	1945	17 days	39

Hottest day (TXx)

The hottest day of the year at Wahiawa Dam 863, 1940 to 1978. The record is 31.7 C (89.1 F) in 1949, marked on the chart; the median year is 31.7 C (89.1 F).

Hottest day (TXx) at Wahiawa Dam 863 by year
Year	Hottest day (TXx)
1940	n/a
1941	n/a
1942	n/a
1943	n/a
1944	n/a
1945	n/a
1946	n/a
1947	n/a
1948	n/a
1949	31.7 C (89.1 F)
1950	n/a
1951	n/a
1952	n/a
1953	n/a
1954	n/a
1955	n/a
1956	n/a
1957	n/a
1958	n/a
1959	n/a
1960	n/a
1961	n/a
1962	n/a
1963	n/a
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

Coldest night (TNn)

The coldest night of the year at Wahiawa Dam 863, 1940 to 1978. The record is 10.0 C (50.0 F) in 1949, marked on the chart; the median year is 10.0 C (50.0 F).

Coldest night (TNn) at Wahiawa Dam 863 by year
Year	Coldest night (TNn)
1940	n/a
1941	n/a
1942	n/a
1943	n/a
1944	n/a
1945	n/a
1946	n/a
1947	n/a
1948	n/a
1949	10.0 C (50.0 F)
1950	n/a
1951	n/a
1952	n/a
1953	n/a
1954	n/a
1955	n/a
1956	n/a
1957	n/a
1958	n/a
1959	n/a
1960	n/a
1961	n/a
1962	n/a
1963	n/a
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

Wettest day (Rx1day)

The wettest day of the year at Wahiawa Dam 863, 1940 to 1978. The record is 255.8 mm (10.1 in) in 1958, marked on the chart; the median year is 89.2 mm (3.5 in).

Wettest day (Rx1day) at Wahiawa Dam 863 by year
Year	Wettest day (Rx1day)
1940	112.0 mm (4.4 in)
1941	22.6 mm (0.9 in)
1942	102.1 mm (4.0 in)
1943	55.9 mm (2.2 in)
1944	113.8 mm (4.5 in)
1945	86.4 mm (3.4 in)
1946	68.6 mm (2.7 in)
1947	52.1 mm (2.1 in)
1948	54.9 mm (2.2 in)
1949	195.3 mm (7.7 in)
1950	164.6 mm (6.5 in)
1951	144.8 mm (5.7 in)
1952	103.9 mm (4.1 in)
1953	31.2 mm (1.2 in)
1954	63.5 mm (2.5 in)
1955	153.4 mm (6.0 in)
1956	126.5 mm (5.0 in)
1957	186.7 mm (7.4 in)
1958	255.8 mm (10.1 in)
1959	110.7 mm (4.4 in)
1960	74.2 mm (2.9 in)
1961	71.9 mm (2.8 in)
1962	140.2 mm (5.5 in)
1963	90.4 mm (3.6 in)
1964	69.1 mm (2.7 in)
1965	154.9 mm (6.1 in)
1966	79.2 mm (3.1 in)
1967	89.2 mm (3.5 in)
1968	77.5 mm (3.1 in)
1969	162.1 mm (6.4 in)
1970	48.8 mm (1.9 in)
1971	119.4 mm (4.7 in)
1972	50.8 mm (2.0 in)
1973	38.4 mm (1.5 in)
1974	69.1 mm (2.7 in)
1975	130.8 mm (5.1 in)
1976	102.1 mm (4.0 in)
1977	46.7 mm (1.8 in)
1978	31.5 mm (1.2 in)

Wettest five days (Rx5day)

The wettest five days of the year at Wahiawa Dam 863, 1940 to 1978. The record is 443.3 mm (17.5 in) in 1957, marked on the chart; the median year is 113.3 mm (4.5 in).

Wettest five days (Rx5day) at Wahiawa Dam 863 by year
Year	Wettest five days (Rx5day)
1940	177.3 mm (7.0 in)
1941	33.8 mm (1.3 in)
1942	222.5 mm (8.8 in)
1943	144.9 mm (5.7 in)
1944	258.6 mm (10.2 in)
1945	164.6 mm (6.5 in)
1946	138.7 mm (5.5 in)
1947	77.3 mm (3.0 in)
1948	85.3 mm (3.4 in)
1949	364.4 mm (14.3 in)
1950	231.2 mm (9.1 in)
1951	305.4 mm (12.0 in)
1952	142.5 mm (5.6 in)
1953	71.2 mm (2.8 in)
1954	104.2 mm (4.1 in)
1955	299.5 mm (11.8 in)
1956	98.5 mm (3.9 in)
1957	443.3 mm (17.5 in)
1958	145.8 mm (5.7 in)
1959	137.6 mm (5.4 in)
1960	84.6 mm (3.3 in)
1961	129.5 mm (5.1 in)
1962	257.0 mm (10.1 in)
1963	189.7 mm (7.5 in)
1964	120.4 mm (4.7 in)
1965	166.6 mm (6.6 in)
1966	89.1 mm (3.5 in)
1967	93.1 mm (3.7 in)
1968	39.6 mm (1.6 in)
1969	22.6 mm (0.9 in)
1970	53.1 mm (2.1 in)
1971	86.0 mm (3.4 in)
1972	15.0 mm (0.6 in)
1973	23.4 mm (0.9 in)
1974	73.7 mm (2.9 in)
1975	13.8 mm (0.5 in)
1976	113.3 mm (4.5 in)
1977	33.1 mm (1.3 in)
1978	2.5 mm (0.10 in)

Longest dry spell (CDD)

The longest dry spell of the year at Wahiawa Dam 863, 1940 to 1978. The record is 36 days in 1945, marked on the chart; the median year is 17 days.

Longest dry spell (CDD) at Wahiawa Dam 863 by year
Year	Longest dry spell (CDD)
1940	25 days
1941	31 days
1942	18 days
1943	15 days
1944	19 days
1945	36 days
1946	19 days
1947	17 days
1948	15 days
1949	18 days
1950	18 days
1951	14 days
1952	27 days
1953	18 days
1954	13 days
1955	17 days
1956	13 days
1957	30 days
1958	11 days
1959	20 days
1960	20 days
1961	10 days
1962	22 days
1963	16 days
1964	16 days
1965	8 days
1966	13 days
1967	14 days
1968	17 days
1969	10 days
1970	23 days
1971	19 days
1972	16 days
1973	19 days
1974	12 days
1975	14 days
1976	11 days
1977	15 days
1978	4 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.

Download the Data

Data for Wahiawa Dam 863 standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Wahiawa Dam 863 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).