Granite Reef Dam Weather Records (USC00023621)

Record envelope, standing records and threshold days for Granite Reef Dam (USC00023621), Arizona, United States, with 87 years of record.

Key Facts for Granite Reef Dam

Granite Reef Dam (USC00023621) is a weather station in Arizona, United States at 33.52 latitude and -111.70 longitude, 403 m (1,322 ft) above sea level.
The station reports from 1893 to 1979, 87 years of record.
1,464 records set at Granite Reef Dam still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Granite Reef Dam tied a daily record low maximum temperature of 31.1 C (88.0 F) on 16 September 1979.

About the Station

Location: Arizona, United States, 33.52 latitude, -111.70 longitude.
Elevation: 403 m (1,322 ft).
Period of record: 1893 to 1979, 87 years.
Eligible elements: tmax, tmin, 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 Granite Reef Dam. 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 Granite Reef Dam, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	30.0 C (86.0 F)	-10.6 C (12.9 F)	n/a	n/a
Feb	33.3 C (91.9 F)	-8.3 C (17.1 F)	n/a	n/a
Mar	36.1 C (97.0 F)	-5.0 C (23.0 F)	n/a	n/a
Apr	40.6 C (105.1 F)	-2.8 C (27.0 F)	n/a	n/a
May	46.1 C (115.0 F)	-0.6 C (30.9 F)	n/a	n/a
Jun	47.2 C (117.0 F)	6.1 C (43.0 F)	n/a	n/a
Jul	49.4 C (120.9 F)	11.1 C (52.0 F)	n/a	n/a
Aug	46.7 C (116.1 F)	13.3 C (55.9 F)	n/a	n/a
Sep	46.1 C (115.0 F)	7.8 C (46.0 F)	n/a	n/a
Oct	41.1 C (106.0 F)	0.6 C (33.1 F)	n/a	n/a
Nov	38.9 C (102.0 F)	-3.9 C (25.0 F)	n/a	n/a
Dec	31.1 C (88.0 F)	-8.9 C (16.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Granite Reef Dam still stand. 1933 holds the most, with 91.

Standing records at Granite Reef Dam by the year they were set
Year set	Standing records
1893	34
1894	5
1895	10
1896	11
1897	12
1898	13
1899	13
1900	13
1901	18
1902	23
1903	11
1904	19
1905	19
1906	23
1907	18
1908	18
1909	17
1910	33
1911	21
1912	17
1913	25
1914	10
1915	18
1916	18
1917	18
1918	20
1919	19
1920	13
1921	23
1922	12
1923	9
1924	8
1925	53
1926	4
1927	11
1928	14
1929	23
1930	34
1931	24
1932	53
1933	91
1934	46
1935	21
1936	15
1937	17
1938	14
1939	21
1940	10
1941	9
1942	6
1943	18
1944	17
1945	10
1946	22
1947	14
1948	8
1949	20
1950	17
1951	13
1952	6
1953	14
1954	10
1955	25
1956	11
1957	15
1958	13
1959	7
1960	13
1961	6
1962	16
1963	9
1964	21
1965	10
1966	4
1967	8
1968	13
1969	4
1970	12
1971	27
1972	10
1973	10
1974	7
1975	14
1976	12
1977	8
1978	6
1979	7

All-Time Record Progression

6 new records

6 all-time records were set at Granite Reef Dam between 16 July 1925 and 28 August 1951. Each dot is a new record.

When Granite Reef Dam set new all-time records
Date	Kind	Detail
1925-07-16	Record high maximum temperature	Record high maximum temperature 49.4 C (120.9 F)
1925-07-16	Record high minimum temperature	Record high minimum temperature 36.7 C (98.1 F)
1937-01-21	Record daily snowfall	Record daily snowfall 7.6 cm (3.0 in)
1943-08-02	Record daily precipitation	Record daily precipitation 63.5 mm (2.5 in)
1943-08-03	Record daily precipitation	Record daily precipitation 66.5 mm (2.6 in)
1951-08-28	Record daily precipitation	Record daily precipitation 81.3 mm (3.2 in)

Wettest Day of Each Month

Aug: 81.3 mm (3.2 in)

The wettest day on record for each calendar month at Granite Reef Dam. The most was 81.3 mm (3.2 in) on 28 August 1951.

Record daily precipitation for each month at Granite Reef Dam
Month	Record daily precipitation (mm)	Date
Jan	40.4 mm (1.6 in)	10 January 1905
Feb	35.8 mm (1.4 in)	14 February 1978
Mar	50.8 mm (2.0 in)	4 March 1943
Apr	43.7 mm (1.7 in)	6 April 1926
May	22.9 mm (0.9 in)	2 May 1941
Jun	30.7 mm (1.2 in)	18 June 1949
Jul	53.3 mm (2.1 in)	25 July 1955
Aug	81.3 mm (3.2 in)	28 August 1951
Sep	60.5 mm (2.4 in)	6 September 1970
Oct	44.5 mm (1.8 in)	27 October 1911
Nov	43.7 mm (1.7 in)	10 November 1923
Dec	58.2 mm (2.3 in)	9 December 1898

Period of Record Coverage

1893 to 1979

87 years of record at Granite Reef Dam, 1893 to 1979. 37 years have data for under 90 percent of days and are left out of rankings: 1894, 1895, 1896, 1897, 1898, 1899, 1904, 1907 and others.

Days with data per year at Granite Reef Dam
Year	Days with data	Share of year	Complete
1893	353	97%	Yes
1894	270	74%	No
1895	208	57%	No
1896	207	57%	No
1897	289	79%	No
1898	301	82%	No
1899	236	65%	No
1900	360	99%	Yes
1901	363	99%	Yes
1902	349	96%	Yes
1903	364	100%	Yes
1904	321	88%	No
1905	363	99%	Yes
1906	334	92%	Yes
1907	252	69%	No
1908	365	100%	Yes
1909	162	44%	No
1910	365	100%	Yes
1911	365	100%	Yes
1912	365	100%	Yes
1913	364	100%	Yes
1914	364	100%	Yes
1915	361	99%	Yes
1916	366	100%	Yes
1917	364	100%	Yes
1918	346	95%	Yes
1919	364	100%	Yes
1920	366	100%	Yes
1921	352	96%	Yes
1922	356	98%	Yes
1923	365	100%	Yes
1924	121	33%	No
1925	350	96%	Yes
1926	149	41%	No
1927	349	96%	Yes
1928	332	91%	Yes
1929	274	75%	No
1930	298	82%	No
1931	331	91%	Yes
1932	305	83%	No
1933	315	86%	No
1934	319	87%	No
1935	307	84%	No
1936	227	62%	No
1937	338	93%	Yes
1938	351	96%	Yes
1939	339	93%	Yes
1940	352	96%	Yes
1941	350	96%	Yes
1942	280	77%	No
1943	358	98%	Yes
1944	364	99%	Yes
1945	350	96%	Yes
1946	365	100%	Yes
1947	365	100%	Yes
1948	330	90%	Yes
1949	332	91%	Yes
1950	334	92%	Yes
1951	336	92%	Yes
1952	332	91%	Yes
1953	326	89%	No
1954	314	86%	No
1955	300	82%	No
1956	284	78%	No
1957	272	75%	No
1958	261	72%	No
1959	270	74%	No
1960	274	75%	No
1961	233	64%	No
1962	204	56%	No
1963	198	54%	No
1964	294	80%	No
1965	312	85%	No
1966	361	99%	Yes
1967	276	76%	No
1968	287	78%	No
1969	353	97%	Yes
1970	353	97%	Yes
1971	362	99%	Yes
1972	365	100%	Yes
1973	364	100%	Yes
1974	364	100%	Yes
1975	364	100%	Yes
1976	313	86%	No
1977	358	98%	Yes
1978	235	64%	No
1979	135	37%	No

Latest Records

Latest records at Granite Reef Dam
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
16 September 1979	Granite Reef Dam, US	daily low max (Tie)	31.1 C (88.0 F)	tie	72 years	7 of 100 (Routine)
9 September 1979	Granite Reef Dam, US	daily high min (Tie)	26.1 C (79.0 F)	tie	68 years	7 of 100 (Routine)
23 August 1979	Granite Reef Dam, US	daily low min	15.0 C (59.0 F)	1.1 C (2.0 F)	83 years	36 of 100 (Notable)
22 August 1979	Granite Reef Dam, US	daily low min	15.6 C (60.1 F)	1.6 C (2.9 F)	61 years	31 of 100 (Routine)
21 August 1979	Granite Reef Dam, US	daily low min (Tie)	14.4 C (57.9 F)	tie	79 years	7 of 100 (Routine)
18 August 1979	Granite Reef Dam, US	daily low min	13.9 C (57.0 F)	1.7 C (3.1 F)	79 years	36 of 100 (Notable)
17 August 1979	Granite Reef Dam, US	daily low min (Tie)	16.1 C (61.0 F)	tie	29 years	4 of 100 (Routine)
13 August 1979	Granite Reef Dam, US	daily low max	28.9 C (84.0 F)	2.8 C (5.0 F)	66 years	38 of 100 (Notable)
13 August 1979	Granite Reef Dam, US	daily low min	16.7 C (62.1 F)	0.5 C (0.9 F)	29 years	17 of 100 (Routine)
25 July 1979	Granite Reef Dam, US	daily low min (Tie)	17.8 C (64.0 F)	tie	34 years	4 of 100 (Routine)
11 July 1979	Granite Reef Dam, US	daily low min (Tie)	14.4 C (57.9 F)	tie	34 years	4 of 100 (Routine)
8 July 1979	Granite Reef Dam, US	daily low min	15.0 C (59.0 F)	0.6 C (1.1 F)	10 years	12 of 100 (Routine)
26 May 1979	Granite Reef Dam, US	daily rain	2.3 mm (0.09 in)	1.5 mm (0.06 in)	77 years	20 of 100 (Routine)
25 May 1979	Granite Reef Dam, US	daily rain	7.9 mm (0.31 in)	6.6 mm (0.26 in)	1 year	19 of 100 (Routine)
21 May 1979	Granite Reef Dam, US	daily low max	23.9 C (75.0 F)	0.5 C (0.9 F)	57 years	26 of 100 (Routine)
17 May 1979	Granite Reef Dam, US	daily rain	1.3 mm (0.05 in)	0.3 mm (0.01 in)	60 years	20 of 100 (Routine)
7 December 1978	Granite Reef Dam, US	daily low min	-7.2 C (19.0 F)	3.3 C (5.9 F)	17 years	21 of 100 (Routine)
25 November 1978	Granite Reef Dam, US	daily rain	18.0 mm (0.7 in)	2.8 mm (0.11 in)	43 years	20 of 100 (Routine)
13 November 1978	Granite Reef Dam, US	daily low max	15.0 C (59.0 F)	2.2 C (4.0 F)	5 years	13 of 100 (Routine)
12 November 1978	Granite Reef Dam, US	daily rain	24.6 mm (1.0 in)	5.0 mm (0.20 in)	5 years	14 of 100 (Routine)

Climate Trend

32 complete years, 1900 to 1977

One stripe for each of 32 complete years at Granite Reef Dam, 1900 to 1977. Blue stripes are years cooler than the station's own mean of 20.9 C (69.7 F); red stripes are warmer. The coolest year was 1965, at 20.1 C (68.2 F), and the warmest was 1910, at 22.2 C (72.0 F). The strongest colour marks a difference of 1.4 C (2.5 F).

Annual mean temperature at Granite Reef Dam as warming stripes, 1900 to 1977
Year	Annual mean temperature	Difference from the station mean
1900	21.1 C	+0.14 C
1901	21.2 C	+0.28 C
1903	21.2 C	+0.27 C
1905	21.6 C	+0.63 C
1908	20.9 C	-0.05 C
1910	22.2 C	+1.30 C
1911	20.8 C	-0.17 C
1912	20.2 C	-0.69 C
1913	20.2 C	-0.69 C
1914	21.7 C	+0.72 C
1915	20.5 C	-0.40 C
1916	20.7 C	-0.24 C
1917	20.8 C	-0.17 C
1919	20.7 C	-0.20 C
1920	20.6 C	-0.33 C
1921	21.7 C	+0.78 C
1922	20.8 C	-0.09 C
1923	20.9 C	-0.04 C
1925	21.9 C	+0.95 C
1944	20.3 C	-0.64 C
1946	21.4 C	+0.47 C
1947	21.7 C	+0.74 C
1965	20.1 C	-0.83 C
1966	20.3 C	-0.64 C
1969	20.9 C	+0.00 C
1970	20.6 C	-0.33 C
1971	20.4 C	-0.54 C
1972	21.3 C	+0.35 C
1973	20.5 C	-0.45 C
1974	20.8 C	-0.17 C
1975	20.3 C	-0.61 C
1977	21.5 C	+0.55 C

The fitted trend in annual mean temperature here over 1900 to 1977 is -0.05 C (-0.13 to 0.02) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.10 F (-0.23 to 0.03) per decade. The slope is a straight line fitted to 32 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Granite Reef Dam
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	-0.05 C (-0.13 to 0.02) per decade	-0.10 F (-0.23 to 0.03) per decade	1900 to 1977	32	Not clearly different from zero
Mean daily maximum	0.07 C (-0.01 to 0.15) per decade	0.13 F (-0.01 to 0.27) per decade	1900 to 1977	32	Not clearly different from zero
Mean daily minimum	-0.2 C (-0.3 to -0.1) per decade	-0.3 F (-0.5 to -0.1) per decade	1900 to 1977	32	Fall

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

1893 to 1979

Yearly extremes at Granite Reef Dam: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	49.4 C (120.9 F)	1925	45.0 C (113.0 F)	87
Coldest night (TNn)	-10.6 C (12.9 F)	1913	-3.3 C (26.1 F)	87
Wettest day (Rx1day)	81.3 mm (3.2 in)	1951	30.7 mm (1.2 in)	87
Wettest five days (Rx5day)	135.8 mm (5.3 in)	1943	45.0 mm (1.8 in)	87
Longest dry spell (CDD)	159 days	1972	69 days	87

Hottest day (TXx)

The hottest day of the year at Granite Reef Dam, 1893 to 1979. The record is 49.4 C (120.9 F) in 1925, marked on the chart; the median year is 45.0 C (113.0 F).

Hottest day (TXx) at Granite Reef Dam by year
Year	Hottest day (TXx)
1893	43.9 C (111.0 F)
1894	44.4 C (111.9 F)
1895	44.4 C (111.9 F)
1896	45.0 C (113.0 F)
1897	43.3 C (109.9 F)
1898	43.3 C (109.9 F)
1899	44.4 C (111.9 F)
1900	43.9 C (111.0 F)
1901	45.0 C (113.0 F)
1902	46.1 C (115.0 F)
1903	44.4 C (111.9 F)
1904	43.3 C (109.9 F)
1905	48.3 C (118.9 F)
1906	45.0 C (113.0 F)
1907	48.9 C (120.0 F)
1908	43.3 C (109.9 F)
1909	43.3 C (109.9 F)
1910	46.1 C (115.0 F)
1911	43.3 C (109.9 F)
1912	45.0 C (113.0 F)
1913	44.4 C (111.9 F)
1914	45.0 C (113.0 F)
1915	45.0 C (113.0 F)
1916	44.4 C (111.9 F)
1917	43.9 C (111.0 F)
1918	45.6 C (114.1 F)
1919	46.1 C (115.0 F)
1920	45.6 C (114.1 F)
1921	43.9 C (111.0 F)
1922	45.6 C (114.1 F)
1923	44.4 C (111.9 F)
1924	38.9 C (102.0 F)
1925	49.4 C (120.9 F)
1926	37.2 C (99.0 F)
1927	47.2 C (117.0 F)
1928	45.6 C (114.1 F)
1929	44.4 C (111.9 F)
1930	45.0 C (113.0 F)
1931	47.8 C (118.0 F)
1932	47.2 C (117.0 F)
1933	46.7 C (116.1 F)
1934	46.1 C (115.0 F)
1935	44.4 C (111.9 F)
1936	46.1 C (115.0 F)
1937	46.1 C (115.0 F)
1938	45.0 C (113.0 F)
1939	45.6 C (114.1 F)
1940	47.2 C (117.0 F)
1941	45.0 C (113.0 F)
1942	47.8 C (118.0 F)
1943	46.7 C (116.1 F)
1944	46.7 C (116.1 F)
1945	46.1 C (115.0 F)
1946	44.4 C (111.9 F)
1947	45.6 C (114.1 F)
1948	45.0 C (113.0 F)
1949	43.9 C (111.0 F)
1950	44.4 C (111.9 F)
1951	44.4 C (111.9 F)
1952	44.4 C (111.9 F)
1953	43.3 C (109.9 F)
1954	44.4 C (111.9 F)
1955	45.6 C (114.1 F)
1956	45.0 C (113.0 F)
1957	46.1 C (115.0 F)
1958	48.3 C (118.9 F)
1959	44.4 C (111.9 F)
1960	46.1 C (115.0 F)
1961	45.6 C (114.1 F)
1962	46.1 C (115.0 F)
1963	44.4 C (111.9 F)
1964	43.9 C (111.0 F)
1965	45.0 C (113.0 F)
1966	47.2 C (117.0 F)
1967	43.3 C (109.9 F)
1968	45.0 C (113.0 F)
1969	45.0 C (113.0 F)
1970	46.7 C (116.1 F)
1971	44.4 C (111.9 F)
1972	45.6 C (114.1 F)
1973	45.6 C (114.1 F)
1974	46.7 C (116.1 F)
1975	45.0 C (113.0 F)
1976	45.0 C (113.0 F)
1977	43.9 C (111.0 F)
1978	46.1 C (115.0 F)
1979	44.4 C (111.9 F)

Coldest night (TNn)

The coldest night of the year at Granite Reef Dam, 1893 to 1979. The record is -10.6 C (12.9 F) in 1913, marked on the chart; the median year is -3.3 C (26.1 F).

Coldest night (TNn) at Granite Reef Dam by year
Year	Coldest night (TNn)
1893	-0.6 C (30.9 F)
1894	0.0 C (32.0 F)
1895	-1.7 C (28.9 F)
1896	2.2 C (36.0 F)
1897	-3.3 C (26.1 F)
1898	-3.3 C (26.1 F)
1899	-3.9 C (25.0 F)
1900	-3.3 C (26.1 F)
1901	-5.6 C (21.9 F)
1902	-1.7 C (28.9 F)
1903	-1.7 C (28.9 F)
1904	-3.9 C (25.0 F)
1905	-3.9 C (25.0 F)
1906	-3.9 C (25.0 F)
1907	-1.7 C (28.9 F)
1908	-0.6 C (30.9 F)
1909	-3.9 C (25.0 F)
1910	-3.9 C (25.0 F)
1911	-4.4 C (24.1 F)
1912	-3.9 C (25.0 F)
1913	-10.6 C (12.9 F)
1914	-1.1 C (30.0 F)
1915	-3.3 C (26.1 F)
1916	-5.0 C (23.0 F)
1917	-1.1 C (30.0 F)
1918	-3.3 C (26.1 F)
1919	-3.3 C (26.1 F)
1920	-2.8 C (27.0 F)
1921	-2.8 C (27.0 F)
1922	-2.2 C (28.0 F)
1923	-1.7 C (28.9 F)
1924	-4.4 C (24.1 F)
1925	-3.9 C (25.0 F)
1926	-3.9 C (25.0 F)
1927	-2.8 C (27.0 F)
1928	-3.9 C (25.0 F)
1929	-3.3 C (26.1 F)
1930	-6.7 C (19.9 F)
1931	-5.0 C (23.0 F)
1932	-8.9 C (16.0 F)
1933	-8.9 C (16.0 F)
1934	-1.7 C (28.9 F)
1935	-2.8 C (27.0 F)
1936	-1.1 C (30.0 F)
1937	-6.7 C (19.9 F)
1938	-1.1 C (30.0 F)
1939	-3.3 C (26.1 F)
1940	-1.1 C (30.0 F)
1941	-3.9 C (25.0 F)
1942	-2.8 C (27.0 F)
1943	-2.8 C (27.0 F)
1944	-2.8 C (27.0 F)
1945	-2.2 C (28.0 F)
1946	-4.4 C (24.1 F)
1947	-4.4 C (24.1 F)
1948	-5.6 C (21.9 F)
1949	-6.1 C (21.0 F)
1950	-7.2 C (19.0 F)
1951	-4.4 C (24.1 F)
1952	-2.8 C (27.0 F)
1953	-6.7 C (19.9 F)
1954	-1.1 C (30.0 F)
1955	-4.4 C (24.1 F)
1956	-3.3 C (26.1 F)
1957	-2.2 C (28.0 F)
1958	-3.3 C (26.1 F)
1959	-2.2 C (28.0 F)
1960	-5.6 C (21.9 F)
1961	-0.6 C (30.9 F)
1962	-6.7 C (19.9 F)
1963	-6.7 C (19.9 F)
1964	-7.2 C (19.0 F)
1965	-4.4 C (24.1 F)
1966	-2.8 C (27.0 F)
1967	-4.4 C (24.1 F)
1968	-2.8 C (27.0 F)
1969	-1.1 C (30.0 F)
1970	-2.8 C (27.0 F)
1971	-5.6 C (21.9 F)
1972	-5.0 C (23.0 F)
1973	-3.9 C (25.0 F)
1974	-5.0 C (23.0 F)
1975	-3.9 C (25.0 F)
1976	-6.1 C (21.0 F)
1977	-3.9 C (25.0 F)
1978	-7.2 C (19.0 F)
1979	5.0 C (41.0 F)

Wettest day (Rx1day)

The wettest day of the year at Granite Reef Dam, 1893 to 1979. The record is 81.3 mm (3.2 in) in 1951, marked on the chart; the median year is 30.7 mm (1.2 in).

Wettest day (Rx1day) at Granite Reef Dam by year
Year	Wettest day (Rx1day)
1893	29.0 mm (1.1 in)
1894	13.7 mm (0.5 in)
1895	12.7 mm (0.5 in)
1896	33.8 mm (1.3 in)
1897	17.8 mm (0.7 in)
1898	58.2 mm (2.3 in)
1899	30.7 mm (1.2 in)
1900	24.1 mm (0.9 in)
1901	22.1 mm (0.9 in)
1902	43.9 mm (1.7 in)
1903	21.8 mm (0.9 in)
1904	44.7 mm (1.8 in)
1905	40.4 mm (1.6 in)
1906	50.8 mm (2.0 in)
1907	22.9 mm (0.9 in)
1908	45.2 mm (1.8 in)
1909	15.0 mm (0.6 in)
1910	20.8 mm (0.8 in)
1911	45.2 mm (1.8 in)
1912	36.3 mm (1.4 in)
1913	35.6 mm (1.4 in)
1914	49.8 mm (2.0 in)
1915	46.2 mm (1.8 in)
1916	50.3 mm (2.0 in)
1917	49.3 mm (1.9 in)
1918	42.4 mm (1.7 in)
1919	37.3 mm (1.5 in)
1920	26.9 mm (1.1 in)
1921	18.3 mm (0.7 in)
1922	36.1 mm (1.4 in)
1923	43.7 mm (1.7 in)
1924	24.6 mm (1.0 in)
1925	41.9 mm (1.6 in)
1926	43.7 mm (1.7 in)
1927	49.5 mm (1.9 in)
1928	19.1 mm (0.8 in)
1929	21.3 mm (0.8 in)
1930	26.2 mm (1.0 in)
1931	30.5 mm (1.2 in)
1932	25.4 mm (1.0 in)
1933	24.6 mm (1.0 in)
1934	25.1 mm (1.0 in)
1935	22.1 mm (0.9 in)
1936	32.0 mm (1.3 in)
1937	33.0 mm (1.3 in)
1938	25.4 mm (1.0 in)
1939	37.3 mm (1.5 in)
1940	43.2 mm (1.7 in)
1941	49.5 mm (1.9 in)
1942	18.8 mm (0.7 in)
1943	66.5 mm (2.6 in)
1944	21.6 mm (0.9 in)
1945	16.5 mm (0.6 in)
1946	54.4 mm (2.1 in)
1947	24.4 mm (1.0 in)
1948	24.9 mm (1.0 in)
1949	30.7 mm (1.2 in)
1950	20.6 mm (0.8 in)
1951	81.3 mm (3.2 in)
1952	27.2 mm (1.1 in)
1953	24.6 mm (1.0 in)
1954	34.3 mm (1.4 in)
1955	53.3 mm (2.1 in)
1956	10.7 mm (0.4 in)
1957	21.6 mm (0.9 in)
1958	47.0 mm (1.9 in)
1959	40.6 mm (1.6 in)
1960	47.0 mm (1.9 in)
1961	19.1 mm (0.8 in)
1962	23.6 mm (0.9 in)
1963	21.1 mm (0.8 in)
1964	55.9 mm (2.2 in)
1965	52.8 mm (2.1 in)
1966	49.3 mm (1.9 in)
1967	42.7 mm (1.7 in)
1968	23.4 mm (0.9 in)
1969	24.4 mm (1.0 in)
1970	60.5 mm (2.4 in)
1971	22.6 mm (0.9 in)
1972	33.0 mm (1.3 in)
1973	23.9 mm (0.9 in)
1974	34.8 mm (1.4 in)
1975	29.0 mm (1.1 in)
1976	17.8 mm (0.7 in)
1977	20.3 mm (0.8 in)
1978	51.6 mm (2.0 in)
1979	9.4 mm (0.37 in)

Wettest five days (Rx5day)

The wettest five days of the year at Granite Reef Dam, 1893 to 1979. The record is 135.8 mm (5.3 in) in 1943, marked on the chart; the median year is 45.0 mm (1.8 in).

Wettest five days (Rx5day) at Granite Reef Dam by year
Year	Wettest five days (Rx5day)
1893	40.2 mm (1.6 in)
1894	26.7 mm (1.1 in)
1895	18.0 mm (0.7 in)
1896	45.7 mm (1.8 in)
1897	45.3 mm (1.8 in)
1898	58.2 mm (2.3 in)
1899	44.7 mm (1.8 in)
1900	57.4 mm (2.3 in)
1901	38.9 mm (1.5 in)
1902	51.3 mm (2.0 in)
1903	30.0 mm (1.2 in)
1904	47.8 mm (1.9 in)
1905	68.4 mm (2.7 in)
1906	81.3 mm (3.2 in)
1907	34.0 mm (1.3 in)
1908	61.9 mm (2.4 in)
1909	15.3 mm (0.6 in)
1910	31.0 mm (1.2 in)
1911	84.1 mm (3.3 in)
1912	51.1 mm (2.0 in)
1913	45.0 mm (1.8 in)
1914	89.4 mm (3.5 in)
1915	60.9 mm (2.4 in)
1916	85.4 mm (3.4 in)
1917	81.8 mm (3.2 in)
1918	63.7 mm (2.5 in)
1919	50.2 mm (2.0 in)
1920	28.9 mm (1.1 in)
1921	36.3 mm (1.4 in)
1922	45.5 mm (1.8 in)
1923	43.7 mm (1.7 in)
1924	40.2 mm (1.6 in)
1925	41.9 mm (1.6 in)
1926	66.6 mm (2.6 in)
1927	55.1 mm (2.2 in)
1928	35.1 mm (1.4 in)
1929	21.3 mm (0.8 in)
1930	35.8 mm (1.4 in)
1931	52.4 mm (2.1 in)
1932	52.8 mm (2.1 in)
1933	39.1 mm (1.5 in)
1934	25.1 mm (1.0 in)
1935	29.6 mm (1.2 in)
1936	58.0 mm (2.3 in)
1937	50.0 mm (2.0 in)
1938	43.7 mm (1.7 in)
1939	45.5 mm (1.8 in)
1940	65.8 mm (2.6 in)
1941	65.8 mm (2.6 in)
1942	27.5 mm (1.1 in)
1943	135.8 mm (5.3 in)
1944	43.0 mm (1.7 in)
1945	26.6 mm (1.0 in)
1946	84.9 mm (3.3 in)
1947	24.4 mm (1.0 in)
1948	28.7 mm (1.1 in)
1949	39.1 mm (1.5 in)
1950	26.2 mm (1.0 in)
1951	120.4 mm (4.7 in)
1952	32.3 mm (1.3 in)
1953	39.6 mm (1.6 in)
1954	44.7 mm (1.8 in)
1955	114.3 mm (4.5 in)
1956	23.4 mm (0.9 in)
1957	39.9 mm (1.6 in)
1958	59.2 mm (2.3 in)
1959	62.2 mm (2.4 in)
1960	63.8 mm (2.5 in)
1961	29.2 mm (1.1 in)
1962	36.3 mm (1.4 in)
1963	36.6 mm (1.4 in)
1964	57.2 mm (2.3 in)
1965	75.9 mm (3.0 in)
1966	64.8 mm (2.6 in)
1967	68.1 mm (2.7 in)
1968	49.8 mm (2.0 in)
1969	24.4 mm (1.0 in)
1970	83.7 mm (3.3 in)
1971	36.6 mm (1.4 in)
1972	68.3 mm (2.7 in)
1973	37.3 mm (1.5 in)
1974	49.7 mm (2.0 in)
1975	30.0 mm (1.2 in)
1976	25.4 mm (1.0 in)
1977	35.2 mm (1.4 in)
1978	60.5 mm (2.4 in)
1979	15.5 mm (0.6 in)

Longest dry spell (CDD)

The longest dry spell of the year at Granite Reef Dam, 1893 to 1979. The record is 159 days in 1972, marked on the chart; the median year is 69 days.

Longest dry spell (CDD) at Granite Reef Dam by year
Year	Longest dry spell (CDD)
1893	67 days
1894	106 days
1895	89 days
1896	71 days
1897	85 days
1898	64 days
1899	75 days
1900	81 days
1901	75 days
1902	54 days
1903	69 days
1904	85 days
1905	59 days
1906	88 days
1907	53 days
1908	51 days
1909	62 days
1910	74 days
1911	89 days
1912	63 days
1913	82 days
1914	39 days
1915	63 days
1916	62 days
1917	102 days
1918	85 days
1919	35 days
1920	54 days
1921	60 days
1922	87 days
1923	53 days
1924	64 days
1925	59 days
1926	34 days
1927	45 days
1928	110 days
1929	100 days
1930	64 days
1931	60 days
1932	64 days
1933	65 days
1934	53 days
1935	57 days
1936	52 days
1937	61 days
1938	58 days
1939	86 days
1940	58 days
1941	75 days
1942	56 days
1943	114 days
1944	51 days
1945	121 days
1946	101 days
1947	91 days
1948	80 days
1949	77 days
1950	87 days
1951	64 days
1952	50 days
1953	135 days
1954	67 days
1955	106 days
1956	95 days
1957	54 days
1958	44 days
1959	89 days
1960	145 days
1961	51 days
1962	40 days
1963	96 days
1964	76 days
1965	40 days
1966	85 days
1967	81 days
1968	63 days
1969	127 days
1970	78 days
1971	109 days
1972	159 days
1973	94 days
1974	108 days
1975	84 days
1976	79 days
1977	62 days
1978	35 days
1979	35 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.

Frost Dates and Growing Season

29 years with a frost

Across 29 years with a frost, the median last spring frost at Granite Reef Dam falls on 19 February and the median first autumn frost on 8 December, which leaves a median of 290 days between them.

Fitted over all years, the growing season changes by -1.0 days per decade at this station.

Frost dates and growing season at Granite Reef Dam
Measure	Median, all years	Earliest period	Recent period (1900 to 1977)	Recent against earliest	Fitted trend
Last spring frost	19 February	n/a	19 February	n/a	+1.8 days per decade
First autumn frost	8 December	n/a	8 December	n/a	+0.8 days per decade
Growing days	290 days	n/a	290 days	n/a	-1.0 days per decade

A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.

Rainfall Return Levels

68 years, 1893 to 1977

A day with at least 34.0 mm (1.3 in) of rain is expected about once in 2 years. A day with at least 75.6 mm (3.0 in) of rain is expected about once in 100 years.

Rainfall return levels at Granite Reef Dam: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	34.0 mm (1.3 in)
5 years	46.6 mm (1.8 in)
10 years	54.3 mm (2.1 in)
25 years	63.4 mm (2.5 in)
50 years	69.7 mm (2.7 in)
100 years	75.6 mm (3.0 in)	Longer than the 68 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, 68 years of values from 1893 to 1977.

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: 81.3 mm (3.2 in) in 1951; 66.5 mm (2.6 in) in 1943; 60.5 mm (2.4 in) in 1970.

Download the Data

Data for Granite Reef Dam standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Granite Reef Dam 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 2026-10-13 (13 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).