Neptune Island Weather Records (ASN00018115)

Record envelope, standing records and threshold days for Neptune Island (ASN00018115), Australia, with 70 years of record.

Key Facts for Neptune Island

Neptune Island (ASN00018115) is a weather station in Australia at -35.34 latitude and 136.12 longitude, 32 m (105 ft) above sea level.
The station reports from 1957 to 2026, 70 years of record.
1,464 records set at Neptune Island still stand.
Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
Neptune Island set a daily record precipitation of 22.0 mm (0.9 in) on 9 October 2026 (provisional).

Provisional Records

Records set in the last 60 days are provisional until they clear the revision window.

About the Station

Location: Australia, -35.34 latitude, 136.12 longitude.
Elevation: 32 m (105 ft).
Period of record: 1957 to 2026, 70 years.
Eligible elements: tmax, tmin, prcp.

Daily Record Envelope and 2026

6 days at or beyond a record

The band shows the record high and record low for each calendar day at Neptune Island. The lines show the 2026 daily maximum and minimum. 6 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at Neptune Island, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	36.9 C (98.4 F)	9.4 C (48.9 F)	28.0 C (82.4 F)	14.7 C (58.5 F)
Feb	35.6 C (96.1 F)	8.9 C (48.0 F)	23.0 C (73.4 F)	18.2 C (64.8 F)
Mar	32.8 C (91.0 F)	9.0 C (48.2 F)	26.5 C (79.7 F)	14.7 C (58.5 F)
Apr	29.4 C (84.9 F)	6.1 C (43.0 F)	24.9 C (76.8 F)	12.4 C (54.3 F)
May	24.0 C (75.2 F)	6.7 C (44.1 F)	21.6 C (70.9 F)	11.6 C (52.9 F)
Jun	21.7 C (71.1 F)	6.4 C (43.5 F)	20.3 C (68.5 F)	10.7 C (51.3 F)
Jul	22.5 C (72.5 F)	5.0 C (41.0 F)	17.6 C (63.7 F)	10.0 C (50.0 F)
Aug	25.9 C (78.6 F)	3.7 C (38.7 F)	18.5 C (65.3 F)	10.4 C (50.7 F)
Sep	27.6 C (81.7 F)	3.8 C (38.8 F)	23.4 C (74.1 F)	11.4 C (52.5 F)
Oct	28.8 C (83.8 F)	6.1 C (43.0 F)	20.2 C (68.4 F)	12.0 C (53.6 F)
Nov	31.2 C (88.2 F)	7.2 C (45.0 F)	n/a	n/a
Dec	33.2 C (91.8 F)	8.2 C (46.8 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Neptune Island still stand. 2013 holds the most, with 49.

Standing records at Neptune Island by the year they were set
Year set	Standing records
1962	29
1963	26
1964	46
1965	36
1966	23
1967	17
1968	38
1969	28
1970	41
1971	16
1972	36
1973	30
1974	25
1975	38
1976	16
1977	24
1978	25
1979	18
1980	20
1981	21
1982	25
1983	20
1984	25
1985	17
1986	23
1987	32
1988	15
1989	20
1990	19
1991	14
1992	13
1993	17
1994	27
1995	12
1996	19
1997	16
1998	16
1999	14
2000	13
2001	19
2002	19
2003	12
2004	17
2005	28
2006	23
2007	26
2008	23
2009	34
2010	17
2011	23
2012	20
2013	49
2014	31
2015	25
2016	20
2017	21
2018	19
2019	12
2020	16
2021	14
2022	6
2023	18
2024	19
2025	30
2026	13

All-Time Record Progression

5 new records

5 all-time records were set at Neptune Island between 3 February 1993 and 16 January 2014. Each dot is a new record.

When Neptune Island set new all-time records
Date	Kind	Detail
1993-02-03	Record high maximum temperature	Record high maximum temperature 35.6 C (96.1 F)
1993-02-03	Record high minimum temperature	Record high minimum temperature 22.9 C (73.2 F)
1997-02-20	Record high minimum temperature	Record high minimum temperature 23.2 C (73.8 F)
2010-01-11	Record high minimum temperature	Record high minimum temperature 23.3 C (73.9 F)
2014-01-16	Record high maximum temperature	Record high maximum temperature 36.9 C (98.4 F)

Wettest Day of Each Month

Sep: 65.4 mm (2.6 in)

The wettest day on record for each calendar month at Neptune Island. The most was 65.4 mm (2.6 in) on 2 September 1992.

Record daily precipitation for each month at Neptune Island
Month	Record daily precipitation (mm)	Date
Jan	25.4 mm (1.0 in)	30 January 1974
Feb	48.4 mm (1.9 in)	19 February 2011
Mar	60.8 mm (2.4 in)	21 March 2011
Apr	41.0 mm (1.6 in)	24 April 1983
May	35.4 mm (1.4 in)	16 May 2026
Jun	44.8 mm (1.8 in)	7 June 1994
Jul	47.0 mm (1.9 in)	20 July 2021
Aug	30.2 mm (1.2 in)	9 August 1984
Sep	65.4 mm (2.6 in)	2 September 1992
Oct	36.0 mm (1.4 in)	18 October 2000
Nov	63.8 mm (2.5 in)	7 November 2005
Dec	32.2 mm (1.3 in)	11 December 2023

Period of Record Coverage

1962 to 2026

65 years of record at Neptune Island, 1962 to 2026. 9 years have data for under 90 percent of days and are left out of rankings: 1976, 1999, 2000, 2001, 2003, 2018, 2019, 2020 and others.

Days with data per year at Neptune Island
Year	Days with data	Share of year	Complete
1962	364	100%	Yes
1963	355	97%	Yes
1964	366	100%	Yes
1965	364	100%	Yes
1966	364	100%	Yes
1967	334	92%	Yes
1968	366	100%	Yes
1969	365	100%	Yes
1970	343	94%	Yes
1971	365	100%	Yes
1972	366	100%	Yes
1973	365	100%	Yes
1974	365	100%	Yes
1975	364	100%	Yes
1976	316	86%	No
1977	365	100%	Yes
1978	365	100%	Yes
1979	365	100%	Yes
1980	366	100%	Yes
1981	365	100%	Yes
1982	365	100%	Yes
1983	365	100%	Yes
1984	366	100%	Yes
1985	334	92%	Yes
1986	365	100%	Yes
1987	365	100%	Yes
1988	366	100%	Yes
1989	365	100%	Yes
1990	365	100%	Yes
1991	365	100%	Yes
1992	366	100%	Yes
1993	365	100%	Yes
1994	365	100%	Yes
1995	363	99%	Yes
1996	353	96%	Yes
1997	365	100%	Yes
1998	364	100%	Yes
1999	311	85%	No
2000	319	87%	No
2001	328	90%	No
2002	363	99%	Yes
2003	228	62%	No
2004	352	96%	Yes
2005	360	99%	Yes
2006	359	98%	Yes
2007	360	99%	Yes
2008	364	99%	Yes
2009	362	99%	Yes
2010	352	96%	Yes
2011	365	100%	Yes
2012	366	100%	Yes
2013	365	100%	Yes
2014	365	100%	Yes
2015	364	100%	Yes
2016	355	97%	Yes
2017	363	99%	Yes
2018	299	82%	No
2019	226	62%	No
2020	232	63%	No
2021	361	99%	Yes
2022	359	98%	Yes
2023	358	98%	Yes
2024	363	99%	Yes
2025	357	98%	Yes
2026	246	67%	No

Latest Records

Latest records at Neptune Island
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
9 October 2026	Neptune Island, AU	daily rain (Provisional)	22.0 mm (0.9 in)	7.8 mm (0.31 in)	33 years	20 of 100 (Routine)
2 October 2026	Neptune Island, AU	daily rain (Provisional)	6.8 mm (0.27 in)	1.7 mm (0.07 in)	67 years	20 of 100 (Routine)
24 September 2026	Neptune Island, AU	daily high max (Provisional)	23.2 C (73.8 F)	0.4 C (0.7 F)	60 years	25 of 100 (Routine)
19 September 2026	Neptune Island, AU	daily high max (Provisional)	23.4 C (74.1 F)	0.4 C (0.7 F)	24 years	14 of 100 (Routine)
25 August 2026	Neptune Island, AU	daily rain (Provisional)	16.8 mm (0.7 in)	1.4 mm (0.06 in)	31 years	19 of 100 (Routine)
20 July 2026	Neptune Island, AU	daily high min	14.4 C (57.9 F)	0.4 C (0.7 F)	24 years	15 of 100 (Routine)
17 June 2026	Neptune Island, AU	daily high min	16.3 C (61.3 F)	0.2 C (0.4 F)	64 years	26 of 100 (Routine)
16 June 2026	Neptune Island, AU	daily high min	15.4 C (59.7 F)	0.1 C (0.2 F)	8 years	8 of 100 (Routine)
12 June 2026	Neptune Island, AU	daily high max	20.3 C (68.5 F)	0.2 C (0.4 F)	37 years	18 of 100 (Routine)
2 June 2026	Neptune Island, AU	daily rain	14.8 mm (0.6 in)	1.4 mm (0.06 in)	40 years	20 of 100 (Routine)
16 May 2026	Neptune Island, AU	monthly rain	35.4 mm (1.4 in)	2.6 mm (0.10 in)	18 years	27 of 100 (Routine)
13 May 2026	Neptune Island, AU	daily high min	17.6 C (63.7 F)	0.6 C (1.1 F)	21 years	15 of 100 (Routine)
1 May 2026	Neptune Island, AU	daily high min	19.1 C (66.4 F)	1.4 C (2.5 F)	4 years	15 of 100 (Routine)
30 April 2026	Neptune Island, AU	daily high max	24.2 C (75.6 F)	1.2 C (2.2 F)	48 years	25 of 100 (Routine)
30 April 2026	Neptune Island, AU	daily high min	18.2 C (64.8 F)	0.8 C (1.4 F)	4 years	11 of 100 (Routine)
24 April 2026	Neptune Island, AU	daily high min	18.8 C (65.8 F)	0.8 C (1.4 F)	24 years	17 of 100 (Routine)
21 April 2026	Neptune Island, AU	daily high max	24.9 C (76.8 F)	0.8 C (1.4 F)	32 years	18 of 100 (Routine)
8 April 2026	Neptune Island, AU	daily rain	3.6 mm (0.14 in)	0.8 mm (0.03 in)	1 year	8 of 100 (Routine)
24 March 2026	Neptune Island, AU	daily high max	26.5 C (79.7 F)	1.2 C (2.2 F)	37 years	22 of 100 (Routine)
24 March 2026	Neptune Island, AU	daily high min	19.4 C (66.9 F)	0.2 C (0.4 F)	20 years	13 of 100 (Routine)

Climate Trend

45 complete years, 1962 to 2025

One stripe for each of 45 complete years at Neptune Island, 1962 to 2025. Blue stripes are years cooler than the station's own mean of 16.2 C (61.2 F); red stripes are warmer. The coolest year was 1964, at 15.4 C (59.6 F), and the warmest was 2013, at 17.3 C (63.1 F). The strongest colour marks a difference of 1.1 C (2.0 F).

Annual mean temperature at Neptune Island as warming stripes, 1962 to 2025
Year	Annual mean temperature	Difference from the station mean
1962	16.0 C	-0.22 C
1963	15.7 C	-0.50 C
1964	15.4 C	-0.87 C
1965	15.7 C	-0.49 C
1968	15.9 C	-0.31 C
1969	15.9 C	-0.37 C
1971	15.5 C	-0.75 C
1972	15.9 C	-0.36 C
1973	16.2 C	-0.01 C
1975	15.9 C	-0.30 C
1977	15.9 C	-0.35 C
1978	15.7 C	-0.51 C
1979	16.0 C	-0.20 C
1980	16.5 C	+0.26 C
1984	15.9 C	-0.32 C
1986	15.7 C	-0.55 C
1987	15.7 C	-0.58 C
1989	16.1 C	-0.12 C
1990	16.4 C	+0.15 C
1991	16.4 C	+0.17 C
1992	15.7 C	-0.51 C
1993	16.5 C	+0.23 C
1994	16.2 C	-0.01 C
1995	15.9 C	-0.33 C
1997	16.3 C	+0.08 C
1998	16.1 C	-0.16 C
2002	16.2 C	-0.06 C
2004	16.3 C	+0.02 C
2005	16.5 C	+0.26 C
2006	16.4 C	+0.18 C
2007	16.9 C	+0.66 C
2008	16.4 C	+0.18 C
2009	16.9 C	+0.69 C
2011	16.6 C	+0.40 C
2012	16.6 C	+0.38 C
2013	17.3 C	+1.03 C
2014	16.9 C	+0.65 C
2015	16.4 C	+0.17 C
2016	16.3 C	+0.08 C
2017	16.8 C	+0.52 C
2021	16.3 C	+0.07 C
2022	16.4 C	+0.15 C
2023	16.5 C	+0.25 C
2024	16.7 C	+0.47 C
2025	17.0 C	+0.81 C

The annual mean temperature here has risen by 0.2 C (0.1 to 0.2) per decade over 1962 to 2025. In Fahrenheit: 0.3 F (0.2 to 0.4) per decade. The slope is a straight line fitted to 45 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Neptune Island
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	0.2 C (0.1 to 0.2) per decade	0.3 F (0.2 to 0.4) per decade	1962 to 2025	45	Rise
Mean daily maximum	0.2 C (0.1 to 0.2) per decade	0.3 F (0.2 to 0.4) per decade	1962 to 2025	45	Rise
Mean daily minimum	0.2 C (0.1 to 0.2) per decade	0.3 F (0.2 to 0.4) per decade	1962 to 2025	45	Rise

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

1957 to 2026

Yearly extremes at Neptune Island: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	36.9 C (98.4 F)	2014	31.0 C (87.8 F)	65
Coldest night (TNn)	3.7 C (38.7 F)	1989	7.1 C (44.8 F)	65
Wettest day (Rx1day)	65.4 mm (2.6 in)	1992	25.7 mm (1.0 in)	65
Wettest five days (Rx5day)	101.2 mm (4.0 in)	1992	44.6 mm (1.8 in)	65
Longest dry spell (CDD)	68 days	1989	32 days	65

Hottest day (TXx)

The hottest day of the year at Neptune Island, 1957 to 2026. The record is 36.9 C (98.4 F) in 2014, marked on the chart; the median year is 31.0 C (87.8 F).

Hottest day (TXx) at Neptune Island by year
Year	Hottest day (TXx)
1957	n/a
1958	n/a
1959	n/a
1960	n/a
1961	n/a
1962	30.6 C (87.1 F)
1963	31.7 C (89.1 F)
1964	29.9 C (85.8 F)
1965	32.8 C (91.0 F)
1966	30.8 C (87.4 F)
1967	29.6 C (85.3 F)
1968	32.8 C (91.0 F)
1969	31.7 C (89.1 F)
1970	29.4 C (84.9 F)
1971	27.8 C (82.0 F)
1972	29.0 C (84.2 F)
1973	33.0 C (91.4 F)
1974	30.4 C (86.7 F)
1975	31.0 C (87.8 F)
1976	30.0 C (86.0 F)
1977	32.7 C (90.9 F)
1978	30.0 C (86.0 F)
1979	31.8 C (89.2 F)
1980	31.5 C (88.7 F)
1981	30.4 C (86.7 F)
1982	35.0 C (95.0 F)
1983	32.5 C (90.5 F)
1984	29.6 C (85.3 F)
1985	34.4 C (93.9 F)
1986	30.6 C (87.1 F)
1987	27.5 C (81.5 F)
1988	33.5 C (92.3 F)
1989	30.4 C (86.7 F)
1990	29.0 C (84.2 F)
1991	30.8 C (87.4 F)
1992	27.7 C (81.9 F)
1993	35.6 C (96.1 F)
1994	32.9 C (91.2 F)
1995	29.6 C (85.3 F)
1996	29.5 C (85.1 F)
1997	32.4 C (90.3 F)
1998	30.8 C (87.4 F)
1999	31.2 C (88.2 F)
2000	30.0 C (86.0 F)
2001	33.0 C (91.4 F)
2002	29.0 C (84.2 F)
2003	31.0 C (87.8 F)
2004	31.0 C (87.8 F)
2005	31.0 C (87.8 F)
2006	34.0 C (93.2 F)
2007	33.2 C (91.8 F)
2008	32.6 C (90.7 F)
2009	32.3 C (90.1 F)
2010	32.5 C (90.5 F)
2011	34.4 C (93.9 F)
2012	33.5 C (92.3 F)
2013	32.7 C (90.9 F)
2014	36.9 C (98.4 F)
2015	31.3 C (88.3 F)
2016	30.3 C (86.5 F)
2017	30.8 C (87.4 F)
2018	33.2 C (91.8 F)
2019	29.7 C (85.5 F)
2020	31.7 C (89.1 F)
2021	30.2 C (86.4 F)
2022	28.1 C (82.6 F)
2023	34.3 C (93.7 F)
2024	31.0 C (87.8 F)
2025	32.3 C (90.1 F)
2026	28.0 C (82.4 F)

Coldest night (TNn)

The coldest night of the year at Neptune Island, 1957 to 2026. The record is 3.7 C (38.7 F) in 1989, marked on the chart; the median year is 7.1 C (44.8 F).

Coldest night (TNn) at Neptune Island by year
Year	Coldest night (TNn)
1957	n/a
1958	n/a
1959	n/a
1960	n/a
1961	n/a
1962	7.8 C (46.0 F)
1963	5.6 C (42.1 F)
1964	5.4 C (41.7 F)
1965	6.1 C (43.0 F)
1966	6.7 C (44.1 F)
1967	6.7 C (44.1 F)
1968	4.4 C (39.9 F)
1969	6.4 C (43.5 F)
1970	6.1 C (43.0 F)
1971	6.1 C (43.0 F)
1972	6.7 C (44.1 F)
1973	8.0 C (46.4 F)
1974	6.0 C (42.8 F)
1975	7.5 C (45.5 F)
1976	6.3 C (43.3 F)
1977	6.7 C (44.1 F)
1978	4.5 C (40.1 F)
1979	7.0 C (44.6 F)
1980	9.0 C (48.2 F)
1981	7.0 C (44.6 F)
1982	7.5 C (45.5 F)
1983	7.6 C (45.7 F)
1984	6.9 C (44.4 F)
1985	7.2 C (45.0 F)
1986	6.5 C (43.7 F)
1987	6.0 C (42.8 F)
1988	5.5 C (41.9 F)
1989	3.7 C (38.7 F)
1990	3.8 C (38.8 F)
1991	9.0 C (48.2 F)
1992	6.8 C (44.2 F)
1993	8.1 C (46.6 F)
1994	5.2 C (41.4 F)
1995	7.4 C (45.3 F)
1996	7.4 C (45.3 F)
1997	5.6 C (42.1 F)
1998	5.4 C (41.7 F)
1999	8.0 C (46.4 F)
2000	7.0 C (44.6 F)
2001	7.0 C (44.6 F)
2002	8.0 C (46.4 F)
2003	8.3 C (46.9 F)
2004	6.7 C (44.1 F)
2005	7.3 C (45.1 F)
2006	8.4 C (47.1 F)
2007	7.8 C (46.0 F)
2008	7.1 C (44.8 F)
2009	7.9 C (46.2 F)
2010	8.4 C (47.1 F)
2011	8.0 C (46.4 F)
2012	6.4 C (43.5 F)
2013	7.4 C (45.3 F)
2014	7.7 C (45.9 F)
2015	7.6 C (45.7 F)
2016	5.0 C (41.0 F)
2017	7.5 C (45.5 F)
2018	7.9 C (46.2 F)
2019	7.6 C (45.7 F)
2020	7.1 C (44.8 F)
2021	7.3 C (45.1 F)
2022	8.3 C (46.9 F)
2023	8.4 C (47.1 F)
2024	8.0 C (46.4 F)
2025	10.0 C (50.0 F)
2026	10.0 C (50.0 F)

Wettest day (Rx1day)

The wettest day of the year at Neptune Island, 1957 to 2026. The record is 65.4 mm (2.6 in) in 1992, marked on the chart; the median year is 25.7 mm (1.0 in).

Wettest day (Rx1day) at Neptune Island by year
Year	Wettest day (Rx1day)
1957	4.1 mm (0.16 in)
1958	25.1 mm (1.0 in)
1959	21.8 mm (0.9 in)
1960	35.3 mm (1.4 in)
1961	22.9 mm (0.9 in)
1962	n/a
1963	0.0 mm (0.00 in)
1964	12.2 mm (0.5 in)
1965	n/a
1966	n/a
1967	1.8 mm (0.07 in)
1968	n/a
1969	n/a
1970	19.1 mm (0.8 in)
1971	35.3 mm (1.4 in)
1972	18.5 mm (0.7 in)
1973	38.4 mm (1.5 in)
1974	27.0 mm (1.1 in)
1975	28.6 mm (1.1 in)
1976	26.2 mm (1.0 in)
1977	13.4 mm (0.5 in)
1978	25.0 mm (1.0 in)
1979	25.6 mm (1.0 in)
1980	25.0 mm (1.0 in)
1981	18.6 mm (0.7 in)
1982	23.8 mm (0.9 in)
1983	43.2 mm (1.7 in)
1984	30.2 mm (1.2 in)
1985	29.0 mm (1.1 in)
1986	43.8 mm (1.7 in)
1987	23.0 mm (0.9 in)
1988	29.6 mm (1.2 in)
1989	17.8 mm (0.7 in)
1990	30.0 mm (1.2 in)
1991	17.6 mm (0.7 in)
1992	65.4 mm (2.6 in)
1993	23.2 mm (0.9 in)
1994	44.8 mm (1.8 in)
1995	19.2 mm (0.8 in)
1996	20.2 mm (0.8 in)
1997	25.7 mm (1.0 in)
1998	29.4 mm (1.2 in)
1999	40.0 mm (1.6 in)
2000	43.0 mm (1.7 in)
2001	17.0 mm (0.7 in)
2002	35.0 mm (1.4 in)
2003	16.4 mm (0.6 in)
2004	17.4 mm (0.7 in)
2005	63.8 mm (2.5 in)
2006	35.6 mm (1.4 in)
2007	32.8 mm (1.3 in)
2008	19.0 mm (0.7 in)
2009	21.4 mm (0.8 in)
2010	47.4 mm (1.9 in)
2011	60.8 mm (2.4 in)
2012	25.2 mm (1.0 in)
2013	40.2 mm (1.6 in)
2014	35.0 mm (1.4 in)
2015	39.2 mm (1.5 in)
2016	16.0 mm (0.6 in)
2017	43.4 mm (1.7 in)
2018	21.8 mm (0.9 in)
2019	20.4 mm (0.8 in)
2020	26.8 mm (1.1 in)
2021	47.0 mm (1.9 in)
2022	31.2 mm (1.2 in)
2023	32.2 mm (1.3 in)
2024	20.8 mm (0.8 in)
2025	14.2 mm (0.6 in)
2026	35.4 mm (1.4 in)

Wettest five days (Rx5day)

The wettest five days of the year at Neptune Island, 1957 to 2026. The record is 101.2 mm (4.0 in) in 1992, marked on the chart; the median year is 44.6 mm (1.8 in).

Wettest five days (Rx5day) at Neptune Island by year
Year	Wettest five days (Rx5day)
1957	4.9 mm (0.19 in)
1958	49.8 mm (2.0 in)
1959	48.2 mm (1.9 in)
1960	41.4 mm (1.6 in)
1961	50.1 mm (2.0 in)
1962	n/a
1963	0.0 mm (0.00 in)
1964	20.1 mm (0.8 in)
1965	n/a
1966	n/a
1967	1.8 mm (0.07 in)
1968	n/a
1969	n/a
1970	38.9 mm (1.5 in)
1971	79.6 mm (3.1 in)
1972	45.6 mm (1.8 in)
1973	41.4 mm (1.6 in)
1974	42.4 mm (1.7 in)
1975	34.4 mm (1.4 in)
1976	41.6 mm (1.6 in)
1977	30.0 mm (1.2 in)
1978	56.8 mm (2.2 in)
1979	42.6 mm (1.7 in)
1980	41.0 mm (1.6 in)
1981	44.8 mm (1.8 in)
1982	44.6 mm (1.8 in)
1983	67.8 mm (2.7 in)
1984	56.4 mm (2.2 in)
1985	42.6 mm (1.7 in)
1986	63.8 mm (2.5 in)
1987	56.2 mm (2.2 in)
1988	33.6 mm (1.3 in)
1989	34.6 mm (1.4 in)
1990	45.4 mm (1.8 in)
1991	41.8 mm (1.6 in)
1992	101.2 mm (4.0 in)
1993	46.0 mm (1.8 in)
1994	60.0 mm (2.4 in)
1995	35.4 mm (1.4 in)
1996	43.0 mm (1.7 in)
1997	39.2 mm (1.5 in)
1998	48.8 mm (1.9 in)
1999	47.0 mm (1.9 in)
2000	74.6 mm (2.9 in)
2001	30.0 mm (1.2 in)
2002	38.4 mm (1.5 in)
2003	37.2 mm (1.5 in)
2004	52.8 mm (2.1 in)
2005	68.4 mm (2.7 in)
2006	40.0 mm (1.6 in)
2007	48.6 mm (1.9 in)
2008	28.2 mm (1.1 in)
2009	36.8 mm (1.4 in)
2010	88.6 mm (3.5 in)
2011	67.0 mm (2.6 in)
2012	47.0 mm (1.9 in)
2013	52.8 mm (2.1 in)
2014	46.8 mm (1.8 in)
2015	39.6 mm (1.6 in)
2016	39.4 mm (1.6 in)
2017	61.6 mm (2.4 in)
2018	65.4 mm (2.6 in)
2019	31.0 mm (1.2 in)
2020	21.8 mm (0.9 in)
2021	68.4 mm (2.7 in)
2022	43.2 mm (1.7 in)
2023	55.2 mm (2.2 in)
2024	45.4 mm (1.8 in)
2025	20.6 mm (0.8 in)
2026	47.8 mm (1.9 in)

Longest dry spell (CDD)

The longest dry spell of the year at Neptune Island, 1957 to 2026. The record is 68 days in 1989, marked on the chart; the median year is 32 days.

Longest dry spell (CDD) at Neptune Island by year
Year	Longest dry spell (CDD)
1957	27 days
1958	19 days
1959	37 days
1960	31 days
1961	34 days
1962	n/a
1963	31 days
1964	4 days
1965	n/a
1966	n/a
1967	27 days
1968	n/a
1969	n/a
1970	37 days
1971	18 days
1972	45 days
1973	23 days
1974	63 days
1975	36 days
1976	27 days
1977	29 days
1978	67 days
1979	34 days
1980	49 days
1981	22 days
1982	41 days
1983	36 days
1984	33 days
1985	50 days
1986	51 days
1987	49 days
1988	31 days
1989	68 days
1990	32 days
1991	62 days
1992	60 days
1993	26 days
1994	42 days
1995	24 days
1996	35 days
1997	37 days
1998	30 days
1999	28 days
2000	39 days
2001	39 days
2002	37 days
2003	26 days
2004	23 days
2005	31 days
2006	60 days
2007	54 days
2008	37 days
2009	61 days
2010	21 days
2011	48 days
2012	28 days
2013	27 days
2014	33 days
2015	35 days
2016	18 days
2017	17 days
2018	26 days
2019	8 days
2020	15 days
2021	21 days
2022	15 days
2023	21 days
2024	42 days
2025	23 days
2026	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

51 years, 1958 to 2024

A day with at least 28.1 mm (1.1 in) of rain is expected about once in 2 years. A day with at least 74.3 mm (2.9 in) of rain is expected about once in 100 years.

Rainfall return levels at Neptune Island: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	28.1 mm (1.1 in)
5 years	38.6 mm (1.5 in)
10 years	46.3 mm (1.8 in)
25 years	56.8 mm (2.2 in)
50 years	65.2 mm (2.6 in)
100 years	74.3 mm (2.9 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 1958 to 2024.

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: 65.4 mm (2.6 in) in 1992; 63.8 mm (2.5 in) in 2005; 60.8 mm (2.4 in) in 2011.

Station Changes

No change in the annual mean temperature of this station was found against its neighbours.

Climate Twins

2007 to 2025 against 1961 to 1990

Over 2007 to 2025, Neptune Island had a mean temperature of 16.7 C (62.0 F) and 416.5 mm (16.4 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Cape Agulhas (South Africa, 9,780 km away), Cape St. Francis (South Africa, 9,496 km away) and Elliston (Australia, 219 km away).

Climate twins of Neptune Island: stations whose 1961 to 1990 climate is closest to its 2007 to 2025 climate
Twin station	Country	Distance away	Mean temperature, 1961-1990	Rain a year, 1961-1990	Climate difference
Cape Agulhas	South Africa	9,780 km (6,077 mi)	17.2 C (62.9 F)	449.1 mm (17.7 in)	0.74
Cape St. Francis	South Africa	9,496 km (5,901 mi)	17.2 C (62.9 F)	633.1 mm (24.9 in)	1.08
Elliston	Australia	219 km (136 mi)	16.4 C (61.5 F)	445.9 mm (17.6 in)	1.10

Twins are stations, not cities. A twin is one of the three stations at least 100 km away whose earlier climate is closest to this station's recent one, so a close match does not mean the two places look alike in other ways. A station move or a gap in a record can change that station's averages. The list describes past climate; it is not a forecast and does not say what caused any change. How twins are found, and a search for any station.

Download the Data

Data for Neptune Island standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Neptune Island 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 2026-10-16 (16 October 2026). Records are computed by this site and are not official.

Data as of 2026-10-16. Last revised 16 October 2026 (2026-10-16).