Subiaco Treatment Plant Weather Records (ASN00009151)

Record envelope, standing records and threshold days for Subiaco Treatment Plant (ASN00009151), Australia, with 58 years of record.

Key Facts for Subiaco Treatment Plant

Subiaco Treatment Plant (ASN00009151) is a weather station in Australia at -31.96 latitude and 115.79 longitude, 20 m (66 ft) above sea level.
The station reports from 1967 to 2024, 58 years of record.
1,464 records set at Subiaco Treatment Plant still stand.
Records are tracked for prcp: an element needs 30 years of data to be eligible.
Subiaco Treatment Plant set a daily record precipitation of 67.0 mm (2.6 in) on 5 June 2023.

About the Station

Location: Australia, -31.96 latitude, 115.79 longitude.
Elevation: 20 m (66 ft).
Period of record: 1967 to 2024, 58 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 Subiaco Treatment Plant. 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 Subiaco Treatment Plant, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	45.5 C (113.9 F)	8.0 C (46.4 F)	n/a	n/a
Feb	45.7 C (114.3 F)	10.5 C (50.9 F)	n/a	n/a
Mar	41.5 C (106.7 F)	7.5 C (45.5 F)	n/a	n/a
Apr	35.5 C (95.9 F)	5.5 C (41.9 F)	n/a	n/a
May	31.0 C (87.8 F)	3.4 C (38.1 F)	n/a	n/a
Jun	25.7 C (78.3 F)	-1.0 C (30.2 F)	n/a	n/a
Jul	26.0 C (78.8 F)	0.0 C (32.0 F)	n/a	n/a
Aug	26.5 C (79.7 F)	1.4 C (34.5 F)	n/a	n/a
Sep	31.9 C (89.4 F)	2.5 C (36.5 F)	n/a	n/a
Oct	36.5 C (97.7 F)	3.2 C (37.8 F)	n/a	n/a
Nov	38.4 C (101.1 F)	5.0 C (41.0 F)	n/a	n/a
Dec	42.0 C (107.6 F)	4.5 C (40.1 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Subiaco Treatment Plant still stand. 1987 holds the most, with 135.

All-Time Record Progression

1 new records

1 all-time records were set at Subiaco Treatment Plant between 16 January 2018 and 16 January 2018. Each dot is a new record.

Wettest Day of Each Month

Jan: 132.4 mm (5.2 in)

The wettest day on record for each calendar month at Subiaco Treatment Plant. The most was 132.4 mm (5.2 in) on 16 January 2018.

Record daily precipitation for each month at Subiaco Treatment Plant
Month	Record daily precipitation (mm)	Date
Jan	132.4 mm (5.2 in)	16 January 2018
Feb	95.6 mm (3.8 in)	10 February 2017
Mar	50.4 mm (2.0 in)	23 March 2010
Apr	62.6 mm (2.5 in)	17 April 2002
May	60.2 mm (2.4 in)	19 May 2005
Jun	77.6 mm (3.1 in)	25 June 1986
Jul	98.0 mm (3.9 in)	29 July 1987
Aug	65.4 mm (2.6 in)	4 August 1994
Sep	44.6 mm (1.8 in)	11 September 1994
Oct	60.2 mm (2.4 in)	18 October 1995
Nov	27.4 mm (1.1 in)	8 November 1984
Dec	31.0 mm (1.2 in)	13 December 2011

Period of Record Coverage

1986 to 2000

14 years of record at Subiaco Treatment Plant, 1986 to 2000. 7 years have data for under 90 percent of days and are left out of rankings: 1986, 1987, 1988, 1989, 1997, 1998, 2000.

Days with data per year at Subiaco Treatment Plant
Year	Days with data	Share of year	Complete
1986	94	26%	No
1987	251	69%	No
1988	309	84%	No
1989	113	31%	No
1991	344	94%	Yes
1992	333	91%	Yes
1993	341	93%	Yes
1994	351	96%	Yes
1995	330	90%	Yes
1996	338	92%	Yes
1997	316	87%	No
1998	272	75%	No
1999	338	93%	Yes
2000	233	64%	No

Latest Records

Latest records at Subiaco Treatment Plant
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
5 June 2023	Subiaco Treatment Plant, AU	daily rain	67.0 mm (2.6 in)	48.0 mm (1.9 in)	18 years	50 of 100 (Notable)
31 March 2023	Subiaco Treatment Plant, AU	daily rain	48.4 mm (1.9 in)	27.0 mm (1.1 in)	14 years	42 of 100 (Notable)
18 November 2022	Subiaco Treatment Plant, AU	daily rain	16.2 mm (0.6 in)	1.2 mm (0.05 in)	24 years	14 of 100 (Routine)
24 October 2022	Subiaco Treatment Plant, AU	daily rain	8.4 mm (0.33 in)	3.8 mm (0.15 in)	48 years	20 of 100 (Routine)
13 September 2022	Subiaco Treatment Plant, AU	daily rain	9.6 mm (0.38 in)	0.6 mm (0.02 in)	15 years	9 of 100 (Routine)
7 August 2022	Subiaco Treatment Plant, AU	daily rain	37.6 mm (1.5 in)	13.6 mm (0.5 in)	45 years	35 of 100 (Notable)
2 August 2022	Subiaco Treatment Plant, AU	daily rain	29.6 mm (1.2 in)	9.4 mm (0.37 in)	32 years	26 of 100 (Routine)
24 May 2022	Subiaco Treatment Plant, AU	daily rain	23.8 mm (0.9 in)	4.2 mm (0.17 in)	48 years	20 of 100 (Routine)
11 April 2022	Subiaco Treatment Plant, AU	daily rain	31.6 mm (1.2 in)	5.4 mm (0.21 in)	32 years	20 of 100 (Routine)
3 March 2022	Subiaco Treatment Plant, AU	daily rain	1.8 mm (0.07 in)	0.4 mm (0.02 in)	0 years	5 of 100 (Routine)
10 November 2021	Subiaco Treatment Plant, AU	daily rain	16.4 mm (0.6 in)	1.9 mm (0.07 in)	16 years	13 of 100 (Routine)
26 September 2021	Subiaco Treatment Plant, AU	daily rain	12.4 mm (0.5 in)	3.4 mm (0.13 in)	46 years	20 of 100 (Routine)
21 July 2021	Subiaco Treatment Plant, AU	daily rain	34.2 mm (1.3 in)	10.2 mm (0.4 in)	32 years	24 of 100 (Routine)
10 July 2021	Subiaco Treatment Plant, AU	daily rain	31.0 mm (1.2 in)	1.0 mm (0.04 in)	4 years	7 of 100 (Routine)
20 June 2021	Subiaco Treatment Plant, AU	daily rain	30.6 mm (1.2 in)	6.6 mm (0.26 in)	27 years	19 of 100 (Routine)
5 May 2021	Subiaco Treatment Plant, AU	daily rain	18.8 mm (0.7 in)	1.6 mm (0.06 in)	40 years	18 of 100 (Routine)
30 April 2021	Subiaco Treatment Plant, AU	daily rain	13.8 mm (0.5 in)	3.5 mm (0.14 in)	14 years	13 of 100 (Routine)
4 March 2021	Subiaco Treatment Plant, AU	daily rain	2.0 mm (0.08 in)	1.4 mm (0.06 in)	47 years	20 of 100 (Routine)
3 March 2021	Subiaco Treatment Plant, AU	daily rain	1.4 mm (0.06 in)	0.9 mm (0.04 in)	38 years	17 of 100 (Routine)
2 March 2021	Subiaco Treatment Plant, AU	daily rain	17.2 mm (0.7 in)	2.0 mm (0.08 in)	4 years	8 of 100 (Routine)

Extremes by Year

1967 to 2024

Yearly extremes at Subiaco Treatment Plant: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	45.7 C (114.3 F)	1991	41.5 C (106.7 F)	14
Coldest night (TNn)	-1.0 C (30.2 F)	1998	1.5 C (34.7 F)	15
Wettest day (Rx1day)	132.4 mm (5.2 in)	2018	45.4 mm (1.8 in)	58
Wettest five days (Rx5day)	148.0 mm (5.8 in)	1986	82.2 mm (3.2 in)	58
Longest dry spell (CDD)	108 days	2024	42 days	58

Hottest day (TXx)

The hottest day of the year at Subiaco Treatment Plant, 1967 to 2024. The record is 45.7 C (114.3 F) in 1991, marked on the chart; the median year is 41.5 C (106.7 F).

Hottest day (TXx) at Subiaco Treatment Plant by year
Year	Hottest day (TXx)
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	32.5 C (90.5 F)
1987	40.5 C (104.9 F)
1988	42.5 C (108.5 F)
1989	42.5 C (108.5 F)
1990	n/a
1991	45.7 C (114.3 F)
1992	39.8 C (103.6 F)
1993	41.5 C (106.7 F)
1994	42.0 C (107.6 F)
1995	41.0 C (105.8 F)
1996	41.5 C (106.7 F)
1997	45.5 C (113.9 F)
1998	43.5 C (110.3 F)
1999	41.5 C (106.7 F)
2000	41.5 C (106.7 F)
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

Coldest night (TNn)

The coldest night of the year at Subiaco Treatment Plant, 1967 to 2024. The record is -1.0 C (30.2 F) in 1998, marked on the chart; the median year is 1.5 C (34.7 F).

Coldest night (TNn) at Subiaco Treatment Plant by year
Year	Coldest night (TNn)
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	1.5 C (34.7 F)
1987	3.5 C (38.3 F)
1988	3.5 C (38.3 F)
1989	2.0 C (35.6 F)
1990	-0.5 C (31.1 F)
1991	1.5 C (34.7 F)
1992	2.0 C (35.6 F)
1993	1.0 C (33.8 F)
1994	1.4 C (34.5 F)
1995	2.1 C (35.8 F)
1996	2.5 C (36.5 F)
1997	0.0 C (32.0 F)
1998	-1.0 C (30.2 F)
1999	1.8 C (35.2 F)
2000	1.5 C (34.7 F)
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

Wettest day (Rx1day)

The wettest day of the year at Subiaco Treatment Plant, 1967 to 2024. The record is 132.4 mm (5.2 in) in 2018, marked on the chart; the median year is 45.4 mm (1.8 in).

Wettest day (Rx1day) at Subiaco Treatment Plant by year
Year	Wettest day (Rx1day)
1967	36.8 mm (1.4 in)
1968	57.9 mm (2.3 in)
1969	55.9 mm (2.2 in)
1970	44.5 mm (1.8 in)
1971	39.1 mm (1.5 in)
1972	45.0 mm (1.8 in)
1973	38.9 mm (1.5 in)
1974	40.8 mm (1.6 in)
1975	28.6 mm (1.1 in)
1976	28.4 mm (1.1 in)
1977	39.3 mm (1.5 in)
1978	60.0 mm (2.4 in)
1979	34.0 mm (1.3 in)
1980	45.4 mm (1.8 in)
1981	56.6 mm (2.2 in)
1982	45.4 mm (1.8 in)
1983	60.0 mm (2.4 in)
1984	50.4 mm (2.0 in)
1985	38.6 mm (1.5 in)
1986	77.6 mm (3.1 in)
1987	98.0 mm (3.9 in)
1988	62.4 mm (2.5 in)
1989	38.2 mm (1.5 in)
1990	34.0 mm (1.3 in)
1991	46.0 mm (1.8 in)
1992	87.2 mm (3.4 in)
1993	40.4 mm (1.6 in)
1994	65.4 mm (2.6 in)
1995	60.2 mm (2.4 in)
1996	38.2 mm (1.5 in)
1997	38.2 mm (1.5 in)
1998	40.0 mm (1.6 in)
1999	48.0 mm (1.9 in)
2000	68.4 mm (2.7 in)
2001	82.0 mm (3.2 in)
2002	62.6 mm (2.5 in)
2003	44.0 mm (1.7 in)
2004	26.7 mm (1.1 in)
2005	60.2 mm (2.4 in)
2006	26.4 mm (1.0 in)
2007	40.5 mm (1.6 in)
2008	30.0 mm (1.2 in)
2009	21.0 mm (0.8 in)
2010	50.4 mm (2.0 in)
2011	64.0 mm (2.5 in)
2012	60.0 mm (2.4 in)
2013	51.0 mm (2.0 in)
2014	49.0 mm (1.9 in)
2015	42.0 mm (1.7 in)
2016	38.0 mm (1.5 in)
2017	95.6 mm (3.8 in)
2018	132.4 mm (5.2 in)
2019	68.0 mm (2.7 in)
2020	27.4 mm (1.1 in)
2021	44.2 mm (1.7 in)
2022	37.6 mm (1.5 in)
2023	67.0 mm (2.6 in)
2024	46.4 mm (1.8 in)

Wettest five days (Rx5day)

The wettest five days of the year at Subiaco Treatment Plant, 1967 to 2024. The record is 148.0 mm (5.8 in) in 1986, marked on the chart; the median year is 82.2 mm (3.2 in).

Wettest five days (Rx5day) at Subiaco Treatment Plant by year
Year	Wettest five days (Rx5day)
1967	52.5 mm (2.1 in)
1968	86.3 mm (3.4 in)
1969	82.9 mm (3.3 in)
1970	95.0 mm (3.7 in)
1971	60.7 mm (2.4 in)
1972	59.8 mm (2.4 in)
1973	90.1 mm (3.5 in)
1974	116.6 mm (4.6 in)
1975	72.2 mm (2.8 in)
1976	58.2 mm (2.3 in)
1977	76.1 mm (3.0 in)
1978	112.6 mm (4.4 in)
1979	70.6 mm (2.8 in)
1980	97.2 mm (3.8 in)
1981	102.4 mm (4.0 in)
1982	99.0 mm (3.9 in)
1983	91.4 mm (3.6 in)
1984	58.0 mm (2.3 in)
1985	79.9 mm (3.1 in)
1986	148.0 mm (5.8 in)
1987	114.4 mm (4.5 in)
1988	95.8 mm (3.8 in)
1989	79.2 mm (3.1 in)
1990	81.1 mm (3.2 in)
1991	129.5 mm (5.1 in)
1992	89.0 mm (3.5 in)
1993	80.0 mm (3.1 in)
1994	101.6 mm (4.0 in)
1995	83.0 mm (3.3 in)
1996	123.4 mm (4.9 in)
1997	93.5 mm (3.7 in)
1998	81.4 mm (3.2 in)
1999	55.2 mm (2.2 in)
2000	79.9 mm (3.1 in)
2001	93.8 mm (3.7 in)
2002	92.9 mm (3.7 in)
2003	60.6 mm (2.4 in)
2004	43.5 mm (1.7 in)
2005	92.0 mm (3.6 in)
2006	44.5 mm (1.8 in)
2007	66.2 mm (2.6 in)
2008	63.0 mm (2.5 in)
2009	68.6 mm (2.7 in)
2010	91.3 mm (3.6 in)
2011	106.9 mm (4.2 in)
2012	67.8 mm (2.7 in)
2013	80.1 mm (3.2 in)
2014	60.8 mm (2.4 in)
2015	74.4 mm (2.9 in)
2016	76.4 mm (3.0 in)
2017	140.4 mm (5.5 in)
2018	138.4 mm (5.4 in)
2019	86.2 mm (3.4 in)
2020	57.6 mm (2.3 in)
2021	69.0 mm (2.7 in)
2022	84.2 mm (3.3 in)
2023	119.6 mm (4.7 in)
2024	75.2 mm (3.0 in)

Longest dry spell (CDD)

The longest dry spell of the year at Subiaco Treatment Plant, 1967 to 2024. The record is 108 days in 2024, marked on the chart; the median year is 42 days.

Longest dry spell (CDD) at Subiaco Treatment Plant by year
Year	Longest dry spell (CDD)
1967	25 days
1968	34 days
1969	51 days
1970	37 days
1971	32 days
1972	61 days
1973	63 days
1974	35 days
1975	79 days
1976	31 days
1977	41 days
1978	36 days
1979	41 days
1980	28 days
1981	48 days
1982	41 days
1983	37 days
1984	99 days
1985	59 days
1986	35 days
1987	65 days
1988	69 days
1989	33 days
1990	42 days
1991	55 days
1992	29 days
1993	49 days
1994	88 days
1995	54 days
1996	43 days
1997	35 days
1998	40 days
1999	43 days
2000	45 days
2001	38 days
2002	60 days
2003	44 days
2004	48 days
2005	68 days
2006	34 days
2007	37 days
2008	29 days
2009	48 days
2010	28 days
2011	65 days
2012	59 days
2013	44 days
2014	25 days
2015	37 days
2016	25 days
2017	30 days
2018	47 days
2019	40 days
2020	56 days
2021	39 days
2022	38 days
2023	61 days
2024	108 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

51 years, 1968 to 2023

A day with at least 47.0 mm (1.9 in) of rain is expected about once in 2 years. A day with at least 120.6 mm (4.7 in) of rain is expected about once in 100 years.

Rainfall return levels at Subiaco Treatment Plant: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	47.0 mm (1.9 in)
5 years	63.9 mm (2.5 in)
10 years	76.2 mm (3.0 in)
25 years	92.9 mm (3.7 in)
50 years	106.4 mm (4.2 in)
100 years	120.6 mm (4.7 in)	Longer than the 51 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, 51 years of values from 1968 to 2023.

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: 132.4 mm (5.2 in) in 2018; 98.0 mm (3.9 in) in 1987; 87.2 mm (3.4 in) in 1992.

Download the Data

Data for Subiaco Treatment Plant standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Subiaco Treatment Plant 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 2026-10-14. Last revised 14 October 2026 (2026-10-14).