Mount Isa Post Office Weather Records (ASN00029125)

Record envelope, standing records and threshold days for Mount Isa Post Office (ASN00029125), Australia, with 46 years of record.

Key Facts for Mount Isa Post Office

Mount Isa Post Office (ASN00029125) is a weather station in Australia at -20.73 latitude and 139.48 longitude, 356 m (1,168 ft) above sea level.
The station reports from 1926 to 1971, 46 years of record.
1,464 records set at Mount Isa Post Office still stand.
Records are tracked for prcp: an element needs 30 years of data to be eligible.
Mount Isa Post Office set a daily record precipitation of 46.7 mm (1.8 in) on 18 March 1971.

About the Station

Location: Australia, -20.73 latitude, 139.48 longitude.
Elevation: 356 m (1,168 ft).
Period of record: 1926 to 1971, 46 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 Mount Isa Post Office. 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 Mount Isa Post Office, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	44.3 C (111.7 F)	15.6 C (60.1 F)	n/a	n/a
Feb	43.3 C (109.9 F)	18.3 C (64.9 F)	n/a	n/a
Mar	41.1 C (106.0 F)	12.2 C (54.0 F)	n/a	n/a
Apr	39.0 C (102.2 F)	11.1 C (52.0 F)	n/a	n/a
May	36.7 C (98.1 F)	5.6 C (42.1 F)	n/a	n/a
Jun	34.5 C (94.1 F)	1.7 C (35.1 F)	n/a	n/a
Jul	32.8 C (91.0 F)	1.7 C (35.1 F)	n/a	n/a
Aug	36.1 C (97.0 F)	1.1 C (34.0 F)	n/a	n/a
Sep	37.5 C (99.5 F)	5.6 C (42.1 F)	n/a	n/a
Oct	41.1 C (106.0 F)	9.4 C (48.9 F)	n/a	n/a
Nov	43.3 C (109.9 F)	14.4 C (57.9 F)	n/a	n/a
Dec	44.1 C (111.4 F)	12.8 C (55.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Mount Isa Post Office still stand. 1958 holds the most, with 158.

Wettest Day of Each Month

Jan: 157.5 mm (6.2 in)

The wettest day on record for each calendar month at Mount Isa Post Office. The most was 157.5 mm (6.2 in) on 14 January 1951.

Record daily precipitation for each month at Mount Isa Post Office
Month	Record daily precipitation (mm)	Date
Jan	157.5 mm (6.2 in)	14 January 1951
Feb	99.1 mm (3.9 in)	2 February 1930
Mar	129.5 mm (5.1 in)	15 March 1950
Apr	93.2 mm (3.7 in)	7 April 1952
May	78.7 mm (3.1 in)	12 May 1968
Jun	65.3 mm (2.6 in)	13 June 1941
Jul	35.6 mm (1.4 in)	17 July 1948
Aug	44.7 mm (1.8 in)	18 August 1947
Sep	26.2 mm (1.0 in)	6 September 1947
Oct	58.4 mm (2.3 in)	2 October 1930
Nov	37.6 mm (1.5 in)	12 November 1940
Dec	88.9 mm (3.5 in)	27 December 1946

Period of Record Coverage

1957 to 1971

15 years of record at Mount Isa Post Office, 1957 to 1971. 4 years have data for under 90 percent of days and are left out of rankings: 1958, 1967, 1970, 1971.

Days with data per year at Mount Isa Post Office
Year	Days with data	Share of year	Complete
1957	356	98%	Yes
1958	325	89%	No
1959	363	99%	Yes
1960	364	99%	Yes
1961	365	100%	Yes
1962	364	100%	Yes
1963	364	100%	Yes
1964	362	99%	Yes
1965	365	100%	Yes
1966	354	97%	Yes
1967	315	86%	No
1968	352	96%	Yes
1969	351	96%	Yes
1970	311	85%	No
1971	84	23%	No

Latest Records

Latest records at Mount Isa Post Office
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
18 March 1971	Mount Isa Post Office, AU	daily rain	46.7 mm (1.8 in)	28.9 mm (1.1 in)	20 years	26 of 100 (Routine)
4 March 1971	Mount Isa Post Office, AU	daily rain	31.0 mm (1.2 in)	12.2 mm (0.5 in)	44 years	23 of 100 (Routine)
6 November 1970	Mount Isa Post Office, AU	daily rain	5.6 mm (0.22 in)	3.8 mm (0.15 in)	13 years	13 of 100 (Routine)
23 September 1970	Mount Isa Post Office, AU	daily rain	21.1 mm (0.8 in)	21.1 mm (0.8 in)	44 years	20 of 100 (Routine)
24 December 1969	Mount Isa Post Office, AU	daily rain	45.7 mm (1.8 in)	17.0 mm (0.7 in)	27 years	23 of 100 (Routine)
23 December 1969	Mount Isa Post Office, AU	daily rain	26.9 mm (1.1 in)	2.3 mm (0.09 in)	39 years	16 of 100 (Routine)
8 July 1969	Mount Isa Post Office, AU	daily rain	5.6 mm (0.22 in)	5.6 mm (0.22 in)	43 years	20 of 100 (Routine)
29 August 1968	Mount Isa Post Office, AU	daily rain	3.8 mm (0.15 in)	2.3 mm (0.09 in)	35 years	16 of 100 (Routine)
19 July 1968	Mount Isa Post Office, AU	daily rain	0.5 mm (0.02 in)	0.5 mm (0.02 in)	42 years	16 of 100 (Routine)
18 July 1968	Mount Isa Post Office, AU	daily rain	1.5 mm (0.06 in)	1.5 mm (0.06 in)	42 years	17 of 100 (Routine)
16 July 1968	Mount Isa Post Office, AU	daily rain	1.3 mm (0.05 in)	1.3 mm (0.05 in)	42 years	17 of 100 (Routine)
15 July 1968	Mount Isa Post Office, AU	daily rain	7.4 mm (0.29 in)	7.4 mm (0.29 in)	42 years	20 of 100 (Routine)
14 July 1968	Mount Isa Post Office, AU	daily rain	6.4 mm (0.25 in)	6.4 mm (0.25 in)	42 years	20 of 100 (Routine)
14 May 1968	Mount Isa Post Office, AU	daily rain	3.8 mm (0.15 in)	0.8 mm (0.03 in)	38 years	15 of 100 (Routine)
13 May 1968	Mount Isa Post Office, AU	daily rain	53.8 mm (2.1 in)	53.3 mm (2.1 in)	8 years	35 of 100 (Notable)
12 May 1968	Mount Isa Post Office, AU	monthly rain	78.7 mm (3.1 in)	9.4 mm (0.37 in)	32 years	28 of 100 (Routine)
29 April 1968	Mount Isa Post Office, AU	daily rain	34.8 mm (1.4 in)	34.8 mm (1.4 in)	42 years	36 of 100 (Notable)
20 June 1967	Mount Isa Post Office, AU	daily rain	0.5 mm (0.02 in)	0.5 mm (0.02 in)	40 years	16 of 100 (Routine)
19 June 1967	Mount Isa Post Office, AU	daily rain	0.3 mm (0.01 in)	0.3 mm (0.01 in)	40 years	16 of 100 (Routine)
6 March 1967	Mount Isa Post Office, AU	daily rain	59.9 mm (2.4 in)	40.6 mm (1.6 in)	16 years	31 of 100 (Routine)

Climate Trend

10 complete years, 1957 to 1969

One stripe for each of 10 complete years at Mount Isa Post Office, 1957 to 1969. Blue stripes are years cooler than the station's own mean of 25.1 C (77.2 F); red stripes are warmer. The coolest year was 1960, at 24.2 C (75.6 F), and the warmest was 1969, at 25.6 C (78.1 F). The strongest colour marks a difference of 1.0 C (1.8 F).

Annual mean temperature at Mount Isa Post Office as warming stripes, 1957 to 1969
Year	Annual mean temperature	Difference from the station mean
1957	25.1 C	-0.02 C
1959	25.1 C	-0.03 C
1960	24.2 C	-0.91 C
1961	24.8 C	-0.28 C
1963	25.3 C	+0.14 C
1964	25.3 C	+0.17 C
1965	25.6 C	+0.46 C
1966	24.9 C	-0.18 C
1968	25.3 C	+0.18 C
1969	25.6 C	+0.48 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

1926 to 1971

Yearly extremes at Mount Isa Post Office: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	44.3 C (111.7 F)	1971	43.3 C (109.9 F)	15
Coldest night (TNn)	1.1 C (34.0 F)	1960	3.9 C (39.0 F)	15
Wettest day (Rx1day)	157.5 mm (6.2 in)	1951	59.9 mm (2.4 in)	46
Wettest five days (Rx5day)	221.7 mm (8.7 in)	1951	92.1 mm (3.6 in)	46
Longest dry spell (CDD)	258 days	1946	121 days	46

Hottest day (TXx)

The hottest day of the year at Mount Isa Post Office, 1926 to 1971. The record is 44.3 C (111.7 F) in 1971, marked on the chart; the median year is 43.3 C (109.9 F).

Hottest day (TXx) at Mount Isa Post Office by year
Year	Hottest day (TXx)
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	n/a
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	n/a
1957	42.2 C (108.0 F)
1958	43.3 C (109.9 F)
1959	43.3 C (109.9 F)
1960	43.3 C (109.9 F)
1961	42.8 C (109.0 F)
1962	42.8 C (109.0 F)
1963	43.3 C (109.9 F)
1964	42.4 C (108.3 F)
1965	43.2 C (109.8 F)
1966	43.9 C (111.0 F)
1967	43.4 C (110.1 F)
1968	42.8 C (109.0 F)
1969	42.2 C (108.0 F)
1970	44.1 C (111.4 F)
1971	44.3 C (111.7 F)

Coldest night (TNn)

The coldest night of the year at Mount Isa Post Office, 1926 to 1971. The record is 1.1 C (34.0 F) in 1960, marked on the chart; the median year is 3.9 C (39.0 F).

Coldest night (TNn) at Mount Isa Post Office by year
Year	Coldest night (TNn)
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	n/a
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	n/a
1957	4.4 C (39.9 F)
1958	3.9 C (39.0 F)
1959	3.9 C (39.0 F)
1960	1.1 C (34.0 F)
1961	1.7 C (35.1 F)
1962	4.4 C (39.9 F)
1963	3.3 C (37.9 F)
1964	3.9 C (39.0 F)
1965	2.2 C (36.0 F)
1966	3.9 C (39.0 F)
1967	4.6 C (40.3 F)
1968	3.9 C (39.0 F)
1969	3.9 C (39.0 F)
1970	5.0 C (41.0 F)
1971	18.7 C (65.7 F)

Wettest day (Rx1day)

The wettest day of the year at Mount Isa Post Office, 1926 to 1971. The record is 157.5 mm (6.2 in) in 1951, marked on the chart; the median year is 59.9 mm (2.4 in).

Wettest day (Rx1day) at Mount Isa Post Office by year
Year	Wettest day (Rx1day)
1926	19.1 mm (0.8 in)
1927	90.2 mm (3.6 in)
1928	39.4 mm (1.6 in)
1929	46.5 mm (1.8 in)
1930	99.1 mm (3.9 in)
1931	42.9 mm (1.7 in)
1932	37.1 mm (1.5 in)
1933	34.3 mm (1.4 in)
1934	45.2 mm (1.8 in)
1935	38.6 mm (1.5 in)
1936	149.9 mm (5.9 in)
1937	52.6 mm (2.1 in)
1938	95.3 mm (3.8 in)
1939	44.5 mm (1.8 in)
1940	77.2 mm (3.0 in)
1941	65.3 mm (2.6 in)
1942	56.4 mm (2.2 in)
1943	67.3 mm (2.6 in)
1944	47.0 mm (1.9 in)
1945	40.6 mm (1.6 in)
1946	88.9 mm (3.5 in)
1947	44.7 mm (1.8 in)
1948	35.6 mm (1.4 in)
1949	46.5 mm (1.8 in)
1950	129.5 mm (5.1 in)
1951	157.5 mm (6.2 in)
1952	93.2 mm (3.7 in)
1953	85.1 mm (3.4 in)
1954	103.9 mm (4.1 in)
1955	60.5 mm (2.4 in)
1956	86.4 mm (3.4 in)
1957	59.2 mm (2.3 in)
1958	44.5 mm (1.8 in)
1959	90.2 mm (3.6 in)
1960	54.1 mm (2.1 in)
1961	61.2 mm (2.4 in)
1962	78.0 mm (3.1 in)
1963	61.0 mm (2.4 in)
1964	74.9 mm (2.9 in)
1965	54.9 mm (2.2 in)
1966	36.6 mm (1.4 in)
1967	64.3 mm (2.5 in)
1968	78.7 mm (3.1 in)
1969	45.7 mm (1.8 in)
1970	21.1 mm (0.8 in)
1971	68.1 mm (2.7 in)

Wettest five days (Rx5day)

The wettest five days of the year at Mount Isa Post Office, 1926 to 1971. The record is 221.7 mm (8.7 in) in 1951, marked on the chart; the median year is 92.1 mm (3.6 in).

Wettest five days (Rx5day) at Mount Isa Post Office by year
Year	Wettest five days (Rx5day)
1926	29.0 mm (1.1 in)
1927	117.7 mm (4.6 in)
1928	62.3 mm (2.5 in)
1929	98.1 mm (3.9 in)
1930	157.6 mm (6.2 in)
1931	56.9 mm (2.2 in)
1932	77.0 mm (3.0 in)
1933	67.9 mm (2.7 in)
1934	73.7 mm (2.9 in)
1935	98.6 mm (3.9 in)
1936	184.7 mm (7.3 in)
1937	121.8 mm (4.8 in)
1938	184.9 mm (7.3 in)
1939	64.8 mm (2.6 in)
1940	92.2 mm (3.6 in)
1941	91.9 mm (3.6 in)
1942	104.6 mm (4.1 in)
1943	67.3 mm (2.6 in)
1944	100.5 mm (4.0 in)
1945	64.1 mm (2.5 in)
1946	136.1 mm (5.4 in)
1947	57.5 mm (2.3 in)
1948	47.0 mm (1.9 in)
1949	89.4 mm (3.5 in)
1950	219.0 mm (8.6 in)
1951	221.7 mm (8.7 in)
1952	107.2 mm (4.2 in)
1953	160.0 mm (6.3 in)
1954	122.4 mm (4.8 in)
1955	149.6 mm (5.9 in)
1956	144.1 mm (5.7 in)
1957	88.2 mm (3.5 in)
1958	61.4 mm (2.4 in)
1959	170.7 mm (6.7 in)
1960	75.7 mm (3.0 in)
1961	67.8 mm (2.7 in)
1962	138.7 mm (5.5 in)
1963	88.9 mm (3.5 in)
1964	126.9 mm (5.0 in)
1965	79.8 mm (3.1 in)
1966	76.5 mm (3.0 in)
1967	90.4 mm (3.6 in)
1968	137.6 mm (5.4 in)
1969	77.2 mm (3.0 in)
1970	21.7 mm (0.9 in)
1971	147.6 mm (5.8 in)

Longest dry spell (CDD)

The longest dry spell of the year at Mount Isa Post Office, 1926 to 1971. The record is 258 days in 1946, marked on the chart; the median year is 121 days.

Longest dry spell (CDD) at Mount Isa Post Office by year
Year	Longest dry spell (CDD)
1926	183 days
1927	183 days
1928	133 days
1929	224 days
1930	67 days
1931	132 days
1932	143 days
1933	81 days
1934	120 days
1935	74 days
1936	62 days
1937	88 days
1938	123 days
1939	58 days
1940	202 days
1941	143 days
1942	136 days
1943	148 days
1944	126 days
1945	151 days
1946	258 days
1947	68 days
1948	140 days
1949	197 days
1950	67 days
1951	121 days
1952	86 days
1953	94 days
1954	149 days
1955	77 days
1956	49 days
1957	119 days
1958	74 days
1959	95 days
1960	134 days
1961	104 days
1962	98 days
1963	203 days
1964	77 days
1965	151 days
1966	75 days
1967	155 days
1968	73 days
1969	103 days
1970	145 days
1971	16 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

43 years, 1927 to 1970

A day with at least 60.3 mm (2.4 in) of rain is expected about once in 2 years. A day with at least 178.2 mm (7.0 in) of rain is expected about once in 100 years.

Rainfall return levels at Mount Isa Post Office: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	60.3 mm (2.4 in)
5 years	86.6 mm (3.4 in)
10 years	105.9 mm (4.2 in)
25 years	132.8 mm (5.2 in)
50 years	154.7 mm (6.1 in)	Longer than the 43 years of record
100 years	178.2 mm (7.0 in)	Longer than the 43 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, 43 years of values from 1927 to 1970.

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: 157.5 mm (6.2 in) in 1951; 149.9 mm (5.9 in) in 1936; 129.5 mm (5.1 in) in 1950.

Download the Data

Data for Mount Isa Post Office standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Mount Isa Post Office 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).