Hanna Weather Records (CA003023000)

Record envelope, standing records and threshold days for Hanna (CA003023000), Alberta, Canada, with 65 years of record.

Key Facts for Hanna

Hanna (CA003023000) is a weather station in Alberta, Canada at 51.58 latitude and -111.85 longitude, 823 m (2,700 ft) above sea level.
The station reports from 1921 to 1985, 65 years of record.
1,464 records set at Hanna still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Hanna set a daily record precipitation of 4.4 mm (0.17 in) on 25 December 1983.

About the Station

Location: Alberta, Canada, 51.58 latitude, -111.85 longitude.
Elevation: 823 m (2,700 ft).
Period of record: 1921 to 1985, 65 years.
Eligible elements: tmax, tmin, prcp, snow.

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 Hanna. 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 Hanna, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	13.9 C (57.0 F)	-45.6 C (-50.1 F)	n/a	n/a
Feb	15.0 C (59.0 F)	-42.8 C (-45.0 F)	n/a	n/a
Mar	20.6 C (69.1 F)	-37.8 C (-36.0 F)	n/a	n/a
Apr	30.6 C (87.1 F)	-29.4 C (-20.9 F)	n/a	n/a
May	33.3 C (91.9 F)	-13.3 C (8.1 F)	n/a	n/a
Jun	38.3 C (100.9 F)	-2.2 C (28.0 F)	n/a	n/a
Jul	38.9 C (102.0 F)	1.1 C (34.0 F)	n/a	n/a
Aug	37.2 C (99.0 F)	-1.1 C (30.0 F)	n/a	n/a
Sep	34.4 C (93.9 F)	-12.2 C (10.0 F)	n/a	n/a
Oct	31.1 C (88.0 F)	-24.4 C (-11.9 F)	n/a	n/a
Nov	24.4 C (75.9 F)	-31.7 C (-25.1 F)	n/a	n/a
Dec	15.0 C (59.0 F)	-46.0 C (-50.8 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Hanna still stand. 1937 holds the most, with 54.

Standing records at Hanna by the year they were set
Year set	Standing records
1921	27
1922	22
1923	19
1924	31
1925	28
1926	10
1927	14
1928	33
1929	36
1930	43
1931	35
1933	31
1934	27
1935	22
1936	26
1937	54
1938	47
1939	46
1940	25
1941	38
1942	41
1943	31
1944	14
1945	14
1946	25
1947	21
1948	27
1949	30
1950	51
1951	49
1952	18
1953	27
1954	45
1955	33
1956	25
1957	21
1958	11
1959	28
1960	14
1961	18
1962	21
1963	28
1964	24
1965	31
1966	13
1967	17
1968	39
1969	18
1970	16
1971	18
1972	22
1973	9
1974	10
1975	21
1976	12
1983	8

All-Time Record Progression

3 new records

3 all-time records were set at Hanna between 13 July 1962 and 24 December 1983. Each dot is a new record.

When Hanna set new all-time records
Date	Kind	Detail
1962-07-13	Record daily precipitation	Record daily precipitation 110.5 mm (4.4 in)
1974-12-22	Record daily snowfall	Record daily snowfall 40.6 cm (16.0 in)
1983-12-24	Record low minimum temperature	Record low minimum temperature -46.0 C (-50.8 F)

Wettest Day of Each Month

Jul: 110.5 mm (4.4 in)

The wettest day on record for each calendar month at Hanna. The most was 110.5 mm (4.4 in) on 13 July 1962.

Record daily precipitation for each month at Hanna
Month	Record daily precipitation (mm)	Date
Jan	25.4 mm (1.0 in)	6 January 1954
Feb	25.4 mm (1.0 in)	11 February 1926
Mar	20.3 mm (0.8 in)	14 March 1974
Apr	25.4 mm (1.0 in)	26 April 1974
May	34.3 mm (1.4 in)	26 May 1923
Jun	75.7 mm (3.0 in)	15 June 1973
Jul	110.5 mm (4.4 in)	13 July 1962
Aug	59.9 mm (2.4 in)	24 August 1953
Sep	48.3 mm (1.9 in)	4 September 1946
Oct	30.5 mm (1.2 in)	8 October 1969
Nov	20.3 mm (0.8 in)	16 November 1929
Dec	40.6 mm (1.6 in)	22 December 1974

Period of Record Coverage

1921 to 1983

56 years of record at Hanna, 1921 to 1983. 17 years have data for under 90 percent of days and are left out of rankings: 1921, 1922, 1923, 1926, 1927, 1931, 1933, 1934 and others.

Days with data per year at Hanna
Year	Days with data	Share of year	Complete
1921	291	80%	No
1922	326	89%	No
1923	264	72%	No
1924	365	100%	Yes
1925	365	100%	Yes
1926	158	43%	No
1927	121	33%	No
1928	353	96%	Yes
1929	332	91%	Yes
1930	364	100%	Yes
1931	303	83%	No
1933	245	67%	No
1934	275	75%	No
1935	273	75%	No
1936	92	25%	No
1937	364	100%	Yes
1938	363	99%	Yes
1939	365	100%	Yes
1940	358	98%	Yes
1941	332	91%	Yes
1942	363	99%	Yes
1943	364	100%	Yes
1944	366	100%	Yes
1945	360	99%	Yes
1946	364	100%	Yes
1947	365	100%	Yes
1948	335	92%	Yes
1949	363	99%	Yes
1950	363	99%	Yes
1951	362	99%	Yes
1952	183	50%	No
1953	333	91%	Yes
1954	356	98%	Yes
1955	365	100%	Yes
1956	366	100%	Yes
1957	365	100%	Yes
1958	365	100%	Yes
1959	364	100%	Yes
1960	347	95%	Yes
1961	268	73%	No
1962	363	99%	Yes
1963	364	100%	Yes
1964	364	99%	Yes
1965	365	100%	Yes
1966	270	74%	No
1967	298	82%	No
1968	366	100%	Yes
1969	365	100%	Yes
1970	325	89%	No
1971	365	100%	Yes
1972	366	100%	Yes
1973	365	100%	Yes
1974	364	100%	Yes
1975	337	92%	Yes
1976	290	79%	No
1983	73	20%	No

Latest Records

Latest records at Hanna
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
25 December 1983	Hanna, CA	daily rain	4.4 mm (0.17 in)	1.9 mm (0.07 in)	44 years	20 of 100 (Routine)
25 December 1983	Hanna, CA	daily snowfall	4.4 cm (1.7 in)	1.9 cm (0.7 in)	44 years	20 of 100 (Routine)
24 December 1983	Hanna, CA	all-time low min	-46.0 C (-50.8 F)	0.4 C (0.7 F)	59 years	43 of 100 (Notable)
23 December 1983	Hanna, CA	daily low max	-30.0 C (-22.0 F)	2.2 C (4.0 F)	49 years	22 of 100 (Routine)
23 December 1983	Hanna, CA	daily low min	-42.0 C (-43.6 F)	9.2 C (16.6 F)	12 years	19 of 100 (Routine)
22 December 1983	Hanna, CA	daily low max	-24.5 C (-12.1 F)	1.2 C (2.2 F)	45 years	20 of 100 (Routine)
22 December 1983	Hanna, CA	daily low min	-35.0 C (-31.0 F)	1.1 C (2.0 F)	18 years	12 of 100 (Routine)
20 December 1983	Hanna, CA	daily low min	-35.5 C (-31.9 F)	0.5 C (0.9 F)	58 years	23 of 100 (Routine)
27 November 1983	Hanna, CA	daily rain	6.0 mm (0.24 in)	3.5 mm (0.14 in)	42 years	20 of 100 (Routine)
27 November 1983	Hanna, CA	daily snowfall	6.0 cm (2.4 in)	3.5 cm (1.4 in)	42 years	27 of 100 (Routine)
3 November 1983	Hanna, CA	daily high max	18.5 C (65.3 F)	0.2 C (0.4 F)	33 years	16 of 100 (Routine)
26 October 1983	Hanna, CA	daily high min	5.0 C (41.0 F)	2.2 C (4.0 F)	14 years	14 of 100 (Routine)
7 July 1983	Hanna, CA	daily rain	20.0 mm (0.8 in)	7.0 mm (0.28 in)	0 years	13 of 100 (Routine)
2 July 1983	Hanna, CA	daily rain	25.0 mm (1.0 in)	5.4 mm (0.21 in)	18 years	16 of 100 (Routine)
18 June 1983	Hanna, CA	daily rain	25.6 mm (1.0 in)	11.6 mm (0.5 in)	52 years	34 of 100 (Routine)
10 January 1983	Hanna, CA	daily rain	8.0 mm (0.31 in)	2.9 mm (0.11 in)	13 years	20 of 100 (Routine)
10 January 1983	Hanna, CA	daily snowfall	8.0 cm (3.1 in)	2.9 cm (1.1 in)	13 years	20 of 100 (Routine)
18 November 1982	Hanna, CA	daily rain	10.0 mm (0.4 in)	4.9 mm (0.19 in)	48 years	20 of 100 (Routine)
18 November 1982	Hanna, CA	daily snowfall	10.0 cm (3.9 in)	4.9 cm (1.9 in)	48 years	33 of 100 (Routine)
28 September 1982	Hanna, CA	daily snowfall	1.0 cm (0.4 in)	1.0 cm (0.4 in)	60 years	20 of 100 (Routine)

Climate Trend

31 complete years, 1924 to 1974

One stripe for each of 31 complete years at Hanna, 1924 to 1974. Blue stripes are years cooler than the station's own mean of 2.5 C (36.5 F); red stripes are warmer. The coolest year was 1950, at -0.7 C (30.7 F), and the warmest was 1938, at 4.9 C (40.9 F). The strongest colour marks a difference of 3.2 C (5.8 F).

Annual mean temperature at Hanna as warming stripes, 1924 to 1974
Year	Annual mean temperature	Difference from the station mean
1924	2.3 C	-0.17 C
1925	2.3 C	-0.13 C
1930	3.9 C	+1.47 C
1938	4.9 C	+2.45 C
1939	3.3 C	+0.80 C
1940	1.3 C	-1.16 C
1942	3.0 C	+0.49 C
1943	2.5 C	+0.05 C
1944	2.9 C	+0.45 C
1945	1.8 C	-0.72 C
1946	2.9 C	+0.45 C
1947	2.3 C	-0.21 C
1949	2.9 C	+0.46 C
1950	-0.7 C	-3.17 C
1951	-0.5 C	-3.02 C
1954	2.7 C	+0.22 C
1955	0.9 C	-1.57 C
1956	2.3 C	-0.22 C
1957	3.2 C	+0.73 C
1958	3.7 C	+1.26 C
1959	2.9 C	+0.44 C
1962	3.7 C	+1.24 C
1963	4.4 C	+1.93 C
1964	2.9 C	+0.44 C
1965	1.0 C	-1.47 C
1968	3.5 C	+1.00 C
1969	2.1 C	-0.34 C
1971	1.8 C	-0.64 C
1972	0.9 C	-1.53 C
1973	2.7 C	+0.24 C
1974	2.8 C	+0.30 C

The fitted trend in annual mean temperature here over 1924 to 1974 is -0.1 C (-0.4 to 0.3) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.1 F (-0.8 to 0.5) per decade. The slope is a straight line fitted to 31 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Hanna
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	-0.1 C (-0.4 to 0.3) per decade	-0.1 F (-0.8 to 0.5) per decade	1924 to 1974	31	Not clearly different from zero
Mean daily maximum	-0.1 C (-0.5 to 0.3) per decade	-0.2 F (-0.8 to 0.5) per decade	1924 to 1974	31	Not clearly different from zero
Mean daily minimum	-0.1 C (-0.4 to 0.3) per decade	-0.1 F (-0.8 to 0.5) per decade	1924 to 1974	31	Not clearly different from zero

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

1921 to 1983

Yearly extremes at Hanna: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	38.9 C (102.0 F)	1941	34.4 C (93.9 F)	56
Coldest night (TNn)	-46.0 C (-50.8 F)	1983	-36.1 C (-33.0 F)	56
Wettest day (Rx1day)	110.5 mm (4.4 in)	1962	30.7 mm (1.2 in)	59
Wettest five days (Rx5day)	135.2 mm (5.3 in)	1962	49.5 mm (1.9 in)	59
Longest dry spell (CDD)	83 days	1928	30 days	59

Hottest day (TXx)

The hottest day of the year at Hanna, 1921 to 1983. The record is 38.9 C (102.0 F) in 1941, marked on the chart; the median year is 34.4 C (93.9 F).

Hottest day (TXx) at Hanna by year
Year	Hottest day (TXx)
1921	36.1 C (97.0 F)
1922	35.6 C (96.1 F)
1923	31.1 C (88.0 F)
1924	36.1 C (97.0 F)
1925	33.9 C (93.0 F)
1926	30.0 C (86.0 F)
1927	31.1 C (88.0 F)
1928	33.9 C (93.0 F)
1929	35.0 C (95.0 F)
1930	33.9 C (93.0 F)
1931	34.4 C (93.9 F)
1933	38.3 C (100.9 F)
1934	34.4 C (93.9 F)
1935	35.0 C (95.0 F)
1936	26.7 C (80.1 F)
1937	38.3 C (100.9 F)
1938	35.6 C (96.1 F)
1939	35.6 C (96.1 F)
1940	33.3 C (91.9 F)
1941	38.9 C (102.0 F)
1942	31.1 C (88.0 F)
1943	33.9 C (93.0 F)
1944	36.1 C (97.0 F)
1945	35.0 C (95.0 F)
1946	33.9 C (93.0 F)
1947	33.3 C (91.9 F)
1948	33.3 C (91.9 F)
1949	34.4 C (93.9 F)
1950	33.3 C (91.9 F)
1951	34.4 C (93.9 F)
1952	34.4 C (93.9 F)
1953	35.0 C (95.0 F)
1954	34.4 C (93.9 F)
1955	36.1 C (97.0 F)
1956	33.9 C (93.0 F)
1957	32.8 C (91.0 F)
1958	32.8 C (91.0 F)
1959	33.3 C (91.9 F)
1960	36.1 C (97.0 F)
1961	37.2 C (99.0 F)
1962	32.8 C (91.0 F)
1963	32.8 C (91.0 F)
1964	34.4 C (93.9 F)
1965	33.3 C (91.9 F)
1966	32.2 C (90.0 F)
1967	34.4 C (93.9 F)
1968	34.4 C (93.9 F)
1969	33.3 C (91.9 F)
1970	34.4 C (93.9 F)
1971	35.0 C (95.0 F)
1972	32.8 C (91.0 F)
1973	32.2 C (90.0 F)
1974	34.4 C (93.9 F)
1975	35.0 C (95.0 F)
1976	32.8 C (91.0 F)
1980	n/a
1981	n/a
1982	n/a
1983	18.5 C (65.3 F)

Coldest night (TNn)

The coldest night of the year at Hanna, 1921 to 1983. The record is -46.0 C (-50.8 F) in 1983, marked on the chart; the median year is -36.1 C (-33.0 F).

Coldest night (TNn) at Hanna by year
Year	Coldest night (TNn)
1921	-33.9 C (-29.0 F)
1922	-35.0 C (-31.0 F)
1923	-39.4 C (-38.9 F)
1924	-45.6 C (-50.1 F)
1925	-32.8 C (-27.0 F)
1926	-28.3 C (-18.9 F)
1927	-41.7 C (-43.1 F)
1928	-42.2 C (-44.0 F)
1929	-41.7 C (-43.1 F)
1930	-37.2 C (-35.0 F)
1931	-24.4 C (-11.9 F)
1933	-31.7 C (-25.1 F)
1934	-36.7 C (-34.1 F)
1935	-40.6 C (-41.1 F)
1936	-34.4 C (-29.9 F)
1937	-34.4 C (-29.9 F)
1938	-36.7 C (-34.1 F)
1939	-42.8 C (-45.0 F)
1940	-36.1 C (-33.0 F)
1941	-31.7 C (-25.1 F)
1942	-32.2 C (-26.0 F)
1943	-39.4 C (-38.9 F)
1944	-33.3 C (-27.9 F)
1945	-31.1 C (-24.0 F)
1946	-33.3 C (-27.9 F)
1947	-42.2 C (-44.0 F)
1948	-32.8 C (-27.0 F)
1949	-40.0 C (-40.0 F)
1950	-45.6 C (-50.1 F)
1951	-40.0 C (-40.0 F)
1952	-20.6 C (-5.1 F)
1953	-28.9 C (-20.0 F)
1954	-38.9 C (-38.0 F)
1955	-33.3 C (-27.9 F)
1956	-38.9 C (-38.0 F)
1957	-34.4 C (-29.9 F)
1958	-34.4 C (-29.9 F)
1959	-31.7 C (-25.1 F)
1960	-35.0 C (-31.0 F)
1961	-32.8 C (-27.0 F)
1962	-37.8 C (-36.0 F)
1963	-34.4 C (-29.9 F)
1964	-36.1 C (-33.0 F)
1965	-36.7 C (-34.1 F)
1966	-37.2 C (-35.0 F)
1967	-31.7 C (-25.1 F)
1968	-37.8 C (-36.0 F)
1969	-42.2 C (-44.0 F)
1970	-39.4 C (-38.9 F)
1971	-39.4 C (-38.9 F)
1972	-43.3 C (-45.9 F)
1973	-33.9 C (-29.0 F)
1974	-37.8 C (-36.0 F)
1975	-33.3 C (-27.9 F)
1976	-35.0 C (-31.0 F)
1980	n/a
1981	n/a
1982	n/a
1983	-46.0 C (-50.8 F)

Wettest day (Rx1day)

The wettest day of the year at Hanna, 1921 to 1983. The record is 110.5 mm (4.4 in) in 1962, marked on the chart; the median year is 30.7 mm (1.2 in).

Wettest day (Rx1day) at Hanna by year
Year	Wettest day (Rx1day)
1921	25.9 mm (1.0 in)
1922	33.0 mm (1.3 in)
1923	57.7 mm (2.3 in)
1924	60.2 mm (2.4 in)
1925	21.6 mm (0.9 in)
1926	25.4 mm (1.0 in)
1927	35.6 mm (1.4 in)
1928	52.3 mm (2.1 in)
1929	24.6 mm (1.0 in)
1930	25.9 mm (1.0 in)
1931	25.9 mm (1.0 in)
1933	20.3 mm (0.8 in)
1934	38.4 mm (1.5 in)
1935	39.4 mm (1.6 in)
1936	5.1 mm (0.20 in)
1937	32.5 mm (1.3 in)
1938	33.0 mm (1.3 in)
1939	31.8 mm (1.3 in)
1940	27.9 mm (1.1 in)
1941	14.5 mm (0.6 in)
1942	35.6 mm (1.4 in)
1943	16.5 mm (0.6 in)
1944	45.2 mm (1.8 in)
1945	17.8 mm (0.7 in)
1946	48.3 mm (1.9 in)
1947	46.2 mm (1.8 in)
1948	20.3 mm (0.8 in)
1949	32.5 mm (1.3 in)
1950	29.2 mm (1.1 in)
1951	38.1 mm (1.5 in)
1952	30.5 mm (1.2 in)
1953	59.9 mm (2.4 in)
1954	37.8 mm (1.5 in)
1955	27.2 mm (1.1 in)
1956	22.1 mm (0.9 in)
1957	32.3 mm (1.3 in)
1958	19.3 mm (0.8 in)
1959	22.9 mm (0.9 in)
1960	26.2 mm (1.0 in)
1961	21.8 mm (0.9 in)
1962	110.5 mm (4.4 in)
1963	53.3 mm (2.1 in)
1964	45.0 mm (1.8 in)
1965	29.5 mm (1.2 in)
1966	33.0 mm (1.3 in)
1967	16.8 mm (0.7 in)
1968	27.9 mm (1.1 in)
1969	42.9 mm (1.7 in)
1970	30.7 mm (1.2 in)
1971	24.9 mm (1.0 in)
1972	64.8 mm (2.6 in)
1973	75.7 mm (3.0 in)
1974	40.6 mm (1.6 in)
1975	18.5 mm (0.7 in)
1976	17.3 mm (0.7 in)
1980	7.0 mm (0.28 in)
1981	28.0 mm (1.1 in)
1982	31.8 mm (1.3 in)
1983	32.2 mm (1.3 in)

Wettest five days (Rx5day)

The wettest five days of the year at Hanna, 1921 to 1983. The record is 135.2 mm (5.3 in) in 1962, marked on the chart; the median year is 49.5 mm (1.9 in).

Wettest five days (Rx5day) at Hanna by year
Year	Wettest five days (Rx5day)
1921	40.9 mm (1.6 in)
1922	58.4 mm (2.3 in)
1923	106.2 mm (4.2 in)
1924	84.8 mm (3.3 in)
1925	29.7 mm (1.2 in)
1926	25.4 mm (1.0 in)
1927	65.8 mm (2.6 in)
1928	57.4 mm (2.3 in)
1929	38.6 mm (1.5 in)
1930	41.6 mm (1.6 in)
1931	39.6 mm (1.6 in)
1933	30.6 mm (1.2 in)
1934	43.9 mm (1.7 in)
1935	43.5 mm (1.7 in)
1936	10.1 mm (0.4 in)
1937	40.1 mm (1.6 in)
1938	51.1 mm (2.0 in)
1939	55.5 mm (2.2 in)
1940	38.8 mm (1.5 in)
1941	26.7 mm (1.1 in)
1942	63.3 mm (2.5 in)
1943	31.2 mm (1.2 in)
1944	56.6 mm (2.2 in)
1945	33.8 mm (1.3 in)
1946	67.6 mm (2.7 in)
1947	62.4 mm (2.5 in)
1948	35.6 mm (1.4 in)
1949	49.5 mm (1.9 in)
1950	70.8 mm (2.8 in)
1951	69.1 mm (2.7 in)
1952	42.9 mm (1.7 in)
1953	60.2 mm (2.4 in)
1954	79.3 mm (3.1 in)
1955	53.1 mm (2.1 in)
1956	52.2 mm (2.1 in)
1957	55.9 mm (2.2 in)
1958	31.2 mm (1.2 in)
1959	49.4 mm (1.9 in)
1960	48.3 mm (1.9 in)
1961	27.9 mm (1.1 in)
1962	135.2 mm (5.3 in)
1963	64.0 mm (2.5 in)
1964	64.6 mm (2.5 in)
1965	42.4 mm (1.7 in)
1966	49.8 mm (2.0 in)
1967	21.9 mm (0.9 in)
1968	63.6 mm (2.5 in)
1969	61.4 mm (2.4 in)
1970	81.3 mm (3.2 in)
1971	43.7 mm (1.7 in)
1972	79.5 mm (3.1 in)
1973	114.9 mm (4.5 in)
1974	40.6 mm (1.6 in)
1975	38.8 mm (1.5 in)
1976	37.5 mm (1.5 in)
1980	11.0 mm (0.4 in)
1981	35.4 mm (1.4 in)
1982	52.0 mm (2.0 in)
1983	61.7 mm (2.4 in)

Longest dry spell (CDD)

The longest dry spell of the year at Hanna, 1921 to 1983. The record is 83 days in 1928, marked on the chart; the median year is 30 days.

Longest dry spell (CDD) at Hanna by year
Year	Longest dry spell (CDD)
1921	18 days
1922	33 days
1923	44 days
1924	31 days
1925	31 days
1926	20 days
1927	10 days
1928	83 days
1929	34 days
1930	26 days
1931	18 days
1933	44 days
1934	41 days
1935	35 days
1936	28 days
1937	27 days
1938	44 days
1939	27 days
1940	28 days
1941	43 days
1942	26 days
1943	28 days
1944	54 days
1945	30 days
1946	31 days
1947	16 days
1948	27 days
1949	36 days
1950	33 days
1951	21 days
1952	37 days
1953	38 days
1954	46 days
1955	30 days
1956	22 days
1957	27 days
1958	25 days
1959	39 days
1960	33 days
1961	30 days
1962	42 days
1963	63 days
1964	23 days
1965	26 days
1966	19 days
1967	28 days
1968	39 days
1969	27 days
1970	28 days
1971	31 days
1972	19 days
1973	31 days
1974	33 days
1975	26 days
1976	50 days
1980	18 days
1981	19 days
1982	31 days
1983	36 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

31 years with a frost

Across 31 years with a frost, the median last spring frost at Hanna falls on 22 May and the median first autumn frost on 14 September, which leaves a median of 118 days between them.

Fitted over all years, the growing season changes by +6.8 days per decade at this station.

Frost dates and growing season at Hanna
Measure	Median, all years	Earliest period	Recent period (1925 to 1974)	Recent against earliest	Fitted trend
Last spring frost	22 May	n/a	22 May	n/a	-4.5 days per decade
First autumn frost	14 September	n/a	14 September	n/a	+2.3 days per decade
Growing days	118 days	n/a	118 days	n/a	+6.8 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

39 years, 1924 to 1983

A day with at least 31.5 mm (1.2 in) of rain is expected about once in 2 years. A day with at least 109.1 mm (4.3 in) of rain is expected about once in 100 years.

Rainfall return levels at Hanna: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	31.5 mm (1.2 in)
5 years	46.1 mm (1.8 in)
10 years	57.8 mm (2.3 in)
25 years	75.5 mm (3.0 in)
50 years	91.1 mm (3.6 in)	Longer than the 39 years of record
100 years	109.1 mm (4.3 in)	Longer than the 39 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, 39 years of values from 1924 to 1983.

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: 110.5 mm (4.4 in) in 1962; 75.7 mm (3.0 in) in 1973; 64.8 mm (2.6 in) in 1972.

Download the Data

Data for Hanna standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Hanna 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 2026-10-17 (17 October 2026). Records are computed by this site and are not official.

Data as of 2026-10-17. Last revised 17 October 2026 (2026-10-17).