Record envelope, standing records and threshold days for Union (USC00238515), Missouri, United States, with 94 years of record.
Key Facts for Union
Union (USC00238515) is a weather station in Missouri, United States at 38.44 latitude and -91.00 longitude, 165 m (540 ft) above sea level.
The station reports from 1916 to 2009, 94 years of record.
1,464 records set at Union still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Union set a daily record precipitation of 42.2 mm (1.7 in) on 20 August 2009.
About the Station
Location: Missouri, United States, 38.44 latitude, -91.00 longitude.
Elevation: 165 m (540 ft).
Period of record: 1916 to 2009, 94 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
0 days at or beyond a record
Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Union. 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 Union, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
25.6 C (78.1 F)
-32.2 C (-26.0 F)
n/a
n/a
Feb
29.4 C (84.9 F)
-32.2 C (-26.0 F)
n/a
n/a
Mar
31.7 C (89.1 F)
-23.3 C (-9.9 F)
n/a
n/a
Apr
34.4 C (93.9 F)
-8.3 C (17.1 F)
n/a
n/a
May
36.1 C (97.0 F)
-2.2 C (28.0 F)
n/a
n/a
Jun
42.8 C (109.0 F)
1.7 C (35.1 F)
n/a
n/a
Jul
47.8 C (118.0 F)
6.7 C (44.1 F)
n/a
n/a
Aug
42.8 C (109.0 F)
5.0 C (41.0 F)
n/a
n/a
Sep
42.8 C (109.0 F)
-1.7 C (28.9 F)
n/a
n/a
Oct
35.6 C (96.1 F)
-10.6 C (12.9 F)
n/a
n/a
Nov
30.6 C (87.1 F)
-18.3 C (-0.9 F)
n/a
n/a
Dec
25.0 C (77.0 F)
-30.6 C (-23.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Union still stand. 1952 holds the most, with 48.
Standing records at Union by the year they were set
Year set
Standing records
1937
17
1938
28
1939
27
1940
35
1941
21
1942
22
1943
31
1944
33
1945
19
1946
21
1947
18
1948
19
1949
19
1950
33
1951
25
1952
48
1953
33
1954
45
1955
18
1956
28
1957
9
1958
17
1959
19
1960
28
1961
21
1962
19
1963
29
1964
15
1965
27
1966
24
1967
25
1968
15
1969
3
1970
14
1971
6
1972
21
1973
14
1974
34
1975
7
1976
32
1977
20
1978
24
1979
26
1980
25
1981
19
1982
20
1983
26
1984
21
1985
14
1986
19
1987
11
1988
16
1989
35
1990
24
1991
25
1992
14
1993
17
1994
12
1995
6
1996
16
1997
13
1998
16
1999
12
2000
20
2001
16
2002
7
2003
9
2004
10
2005
11
2006
16
2007
11
2008
7
2009
7
All-Time Record Progression
8 new records
8 all-time records were set at Union between 15 June 1957 and 22 December 1989. Each dot is a new record.
When Union set new all-time records
Date
Kind
Detail
1957-06-15
Record daily precipitation
Record daily precipitation 192.0 mm (7.6 in)
1972-01-15
Record low maximum temperature
Record low maximum temperature -13.9 C (7.0 F)
1974-01-01
Record low maximum temperature
Record low maximum temperature -14.4 C (6.1 F)
1982-01-31
Record daily snowfall
Record daily snowfall 29.2 cm (11.5 in)
1983-12-19
Record low maximum temperature
Record low maximum temperature -15.0 C (5.0 F)
1983-12-23
Record low maximum temperature
Record low maximum temperature -16.1 C (3.0 F)
1983-12-24
Record low maximum temperature
Record low maximum temperature -17.8 C (0.0 F)
1989-12-22
Record low maximum temperature
Record low maximum temperature -18.3 C (-0.9 F)
Wettest Day of Each Month
Jun: 192.0 mm (7.6 in)
The wettest day on record for each calendar month at Union. The most was 192.0 mm (7.6 in) on 15 June 1957.
Record daily precipitation for each month at Union
Month
Record daily precipitation (mm)
Date
Jan
77.7 mm (3.1 in)
5 January 2005
Feb
67.1 mm (2.6 in)
10 February 1959
Mar
64.0 mm (2.5 in)
28 March 1977
Apr
110.5 mm (4.4 in)
29 April 1996
May
81.3 mm (3.2 in)
31 May 1927
Jun
192.0 mm (7.6 in)
15 June 1957
Jul
115.3 mm (4.5 in)
26 July 1948
Aug
106.7 mm (4.2 in)
16 August 1934
Sep
120.7 mm (4.8 in)
23 September 1993
Oct
83.3 mm (3.3 in)
31 October 1942
Nov
128.3 mm (5.1 in)
1 November 1946
Dec
90.9 mm (3.6 in)
27 December 1942
Period of Record Coverage
1937 to 2009
Complete yearUnder 90 percent of days
73 years of record at Union, 1937 to 2009. 4 years have data for under 90 percent of days and are left out of rankings: 1937, 1956, 1971, 2009.
Cooler than the station meanWarmer than the station mean
One stripe for each of 66 complete years at Union, 1938 to 2008. Blue stripes are years cooler than the station's own mean of 13.3 C (55.9 F); red stripes are warmer. The coolest year was 1978, at 11.6 C (52.9 F), and the warmest was 1938, at 14.9 C (58.8 F). The strongest colour marks a difference of 1.8 C (3.2 F).
Annual mean temperature at Union as warming stripes, 1938 to 2008
Year
Annual mean temperature
Difference from the station mean
1938
14.9 C
+1.61 C
1939
14.1 C
+0.79 C
1940
12.7 C
-0.61 C
1941
14.3 C
+1.02 C
1942
13.5 C
+0.17 C
1945
12.9 C
-0.45 C
1946
14.4 C
+1.08 C
1947
13.1 C
-0.21 C
1948
12.6 C
-0.66 C
1949
13.1 C
-0.17 C
1950
12.1 C
-1.23 C
1952
13.6 C
+0.32 C
1953
14.1 C
+0.78 C
1954
14.6 C
+1.26 C
1955
13.5 C
+0.17 C
1957
13.2 C
-0.13 C
1958
12.1 C
-1.23 C
1959
13.3 C
+0.02 C
1960
12.4 C
-0.88 C
1961
12.5 C
-0.82 C
1962
13.0 C
-0.33 C
1963
12.9 C
-0.43 C
1964
13.5 C
+0.23 C
1965
13.6 C
+0.28 C
1966
12.3 C
-0.98 C
1967
12.7 C
-0.63 C
1968
12.5 C
-0.79 C
1969
12.3 C
-1.03 C
1970
12.8 C
-0.51 C
1972
12.7 C
-0.63 C
1973
13.5 C
+0.20 C
1974
13.1 C
-0.24 C
1975
13.2 C
-0.11 C
1976
12.5 C
-0.82 C
1977
13.1 C
-0.21 C
1978
11.6 C
-1.70 C
1979
11.7 C
-1.56 C
1980
13.1 C
-0.16 C
1981
13.2 C
-0.06 C
1982
12.7 C
-0.58 C
1983
13.0 C
-0.35 C
1984
13.3 C
+0.01 C
1985
12.8 C
-0.46 C
1986
14.2 C
+0.85 C
1987
14.3 C
+1.04 C
1988
13.3 C
-0.03 C
1989
12.7 C
-0.57 C
1990
14.4 C
+1.14 C
1991
14.3 C
+1.01 C
1992
13.3 C
-0.01 C
1993
12.5 C
-0.80 C
1994
13.5 C
+0.15 C
1995
13.1 C
-0.23 C
1996
12.5 C
-0.83 C
1997
12.8 C
-0.51 C
1998
14.9 C
+1.56 C
1999
14.8 C
+1.54 C
2000
14.2 C
+0.88 C
2001
14.1 C
+0.84 C
2002
13.8 C
+0.51 C
2003
13.4 C
+0.06 C
2004
13.7 C
+0.40 C
2005
14.3 C
+1.01 C
2006
14.7 C
+1.36 C
2007
14.5 C
+1.21 C
2008
13.0 C
-0.29 C
The fitted trend in annual mean temperature here over 1938 to 2008 is 0.07 C (-0.03 to 0.16) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.1 F (-0.1 to 0.3) per decade. The slope is a straight line fitted to 66 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Union
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.07 C (-0.03 to 0.16) per decade
0.1 F (-0.1 to 0.3) per decade
1938 to 2008
66
Not clearly different from zero
Mean daily maximum
-0.04 C (-0.15 to 0.08) per decade
-0.1 F (-0.3 to 0.1) per decade
1938 to 2008
66
Not clearly different from zero
Mean daily minimum
0.2 C (0.1 to 0.3) per decade
0.3 F (0.1 to 0.5) per decade
1938 to 2008
66
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
1916 to 2009
Yearly extremes at Union: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
47.8 C (118.0 F)
1954
38.9 C (102.0 F)
73
Coldest night (TNn)
-32.2 C (-26.0 F)
1951
-21.1 C (-6.0 F)
73
Wettest day (Rx1day)
192.0 mm (7.6 in)
1957
65.3 mm (2.6 in)
94
Wettest five days (Rx5day)
282.8 mm (11.1 in)
1957
100.1 mm (3.9 in)
94
Longest dry spell (CDD)
38 days
1919
21 days
94
Hottest day (TXx)
The hottest day of the year at Union, 1916 to 2009. The record is 47.8 C (118.0 F) in 1954, marked on the chart; the median year is 38.9 C (102.0 F).
Hottest day (TXx) at Union by year
Year
Hottest day (TXx)
1916
n/a
1917
n/a
1918
n/a
1919
n/a
1920
n/a
1921
n/a
1922
n/a
1923
n/a
1924
n/a
1925
n/a
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
38.3 C (100.9 F)
1938
41.1 C (106.0 F)
1939
38.9 C (102.0 F)
1940
40.0 C (104.0 F)
1941
39.4 C (102.9 F)
1942
38.9 C (102.0 F)
1943
40.0 C (104.0 F)
1944
41.7 C (107.1 F)
1945
38.3 C (100.9 F)
1946
40.6 C (105.1 F)
1947
42.8 C (109.0 F)
1948
37.8 C (100.0 F)
1949
36.7 C (98.1 F)
1950
34.4 C (93.9 F)
1951
35.6 C (96.1 F)
1952
42.8 C (109.0 F)
1953
42.2 C (108.0 F)
1954
47.8 C (118.0 F)
1955
38.9 C (102.0 F)
1956
41.7 C (107.1 F)
1957
36.1 C (97.0 F)
1958
35.6 C (96.1 F)
1959
36.7 C (98.1 F)
1960
38.3 C (100.9 F)
1961
36.1 C (97.0 F)
1962
41.1 C (106.0 F)
1963
40.6 C (105.1 F)
1964
41.1 C (106.0 F)
1965
39.4 C (102.9 F)
1966
40.6 C (105.1 F)
1967
33.9 C (93.0 F)
1968
37.8 C (100.0 F)
1969
35.0 C (95.0 F)
1970
39.4 C (102.9 F)
1971
36.1 C (97.0 F)
1972
37.8 C (100.0 F)
1973
37.2 C (99.0 F)
1974
38.3 C (100.9 F)
1975
37.8 C (100.0 F)
1976
39.4 C (102.9 F)
1977
36.7 C (98.1 F)
1978
37.2 C (99.0 F)
1979
36.7 C (98.1 F)
1980
41.7 C (107.1 F)
1981
36.7 C (98.1 F)
1982
36.7 C (98.1 F)
1983
39.4 C (102.9 F)
1984
42.8 C (109.0 F)
1985
36.7 C (98.1 F)
1986
40.0 C (104.0 F)
1987
41.1 C (106.0 F)
1988
40.0 C (104.0 F)
1989
37.2 C (99.0 F)
1990
38.9 C (102.0 F)
1991
40.6 C (105.1 F)
1992
36.7 C (98.1 F)
1993
37.2 C (99.0 F)
1994
37.2 C (99.0 F)
1995
38.9 C (102.0 F)
1996
38.3 C (100.9 F)
1997
38.9 C (102.0 F)
1998
38.3 C (100.9 F)
1999
40.6 C (105.1 F)
2000
40.0 C (104.0 F)
2001
38.3 C (100.9 F)
2002
38.3 C (100.9 F)
2003
40.0 C (104.0 F)
2004
37.8 C (100.0 F)
2005
39.4 C (102.9 F)
2006
38.9 C (102.0 F)
2007
42.2 C (108.0 F)
2008
36.7 C (98.1 F)
2009
35.6 C (96.1 F)
Coldest night (TNn)
The coldest night of the year at Union, 1916 to 2009. The record is -32.2 C (-26.0 F) in 1951, marked on the chart; the median year is -21.1 C (-6.0 F).
Coldest night (TNn) at Union by year
Year
Coldest night (TNn)
1916
n/a
1917
n/a
1918
n/a
1919
n/a
1920
n/a
1921
n/a
1922
n/a
1923
n/a
1924
n/a
1925
n/a
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
-16.7 C (1.9 F)
1938
-15.0 C (5.0 F)
1939
-17.8 C (0.0 F)
1940
-23.3 C (-9.9 F)
1941
-12.8 C (9.0 F)
1942
-21.1 C (-6.0 F)
1943
-22.2 C (-8.0 F)
1944
-18.3 C (-0.9 F)
1945
-17.8 C (0.0 F)
1946
-17.8 C (0.0 F)
1947
-18.9 C (-2.0 F)
1948
-25.6 C (-14.1 F)
1949
-20.6 C (-5.1 F)
1950
-20.6 C (-5.1 F)
1951
-32.2 C (-26.0 F)
1952
-15.0 C (5.0 F)
1953
-17.2 C (1.0 F)
1954
-16.1 C (3.0 F)
1955
-17.8 C (0.0 F)
1956
-21.1 C (-6.0 F)
1957
-17.2 C (1.0 F)
1958
-22.2 C (-8.0 F)
1959
-25.6 C (-14.1 F)
1960
-22.8 C (-9.0 F)
1961
-27.8 C (-18.0 F)
1962
-23.9 C (-11.0 F)
1963
-27.2 C (-17.0 F)
1964
-24.4 C (-11.9 F)
1965
-22.2 C (-8.0 F)
1966
-22.2 C (-8.0 F)
1967
-18.9 C (-2.0 F)
1968
-22.8 C (-9.0 F)
1969
-18.3 C (-0.9 F)
1970
-22.8 C (-9.0 F)
1971
-17.8 C (0.0 F)
1972
-22.8 C (-9.0 F)
1973
-24.4 C (-11.9 F)
1974
-25.6 C (-14.1 F)
1975
-16.7 C (1.9 F)
1976
-22.2 C (-8.0 F)
1977
-32.2 C (-26.0 F)
1978
-23.9 C (-11.0 F)
1979
-29.4 C (-20.9 F)
1980
-23.9 C (-11.0 F)
1981
-26.7 C (-16.1 F)
1982
-28.3 C (-18.9 F)
1983
-28.3 C (-18.9 F)
1984
-25.6 C (-14.1 F)
1985
-26.1 C (-15.0 F)
1986
-20.6 C (-5.1 F)
1987
-16.7 C (1.9 F)
1988
-21.7 C (-7.1 F)
1989
-30.6 C (-23.1 F)
1990
-22.8 C (-9.0 F)
1991
-13.9 C (7.0 F)
1992
-15.6 C (3.9 F)
1993
-20.0 C (-4.0 F)
1994
-24.4 C (-11.9 F)
1995
-17.8 C (0.0 F)
1996
-25.0 C (-13.0 F)
1997
-27.2 C (-17.0 F)
1998
-15.0 C (5.0 F)
1999
-26.1 C (-15.0 F)
2000
-18.9 C (-2.0 F)
2001
-22.8 C (-9.0 F)
2002
-17.8 C (0.0 F)
2003
-20.6 C (-5.1 F)
2004
-17.2 C (1.0 F)
2005
-17.8 C (0.0 F)
2006
-15.0 C (5.0 F)
2007
-17.8 C (0.0 F)
2008
-16.7 C (1.9 F)
2009
-18.9 C (-2.0 F)
Wettest day (Rx1day)
The wettest day of the year at Union, 1916 to 2009. The record is 192.0 mm (7.6 in) in 1957, marked on the chart; the median year is 65.3 mm (2.6 in).
Wettest day (Rx1day) at Union by year
Year
Wettest day (Rx1day)
1916
40.6 mm (1.6 in)
1917
50.8 mm (2.0 in)
1918
72.6 mm (2.9 in)
1919
63.5 mm (2.5 in)
1920
49.5 mm (1.9 in)
1921
59.2 mm (2.3 in)
1922
87.6 mm (3.4 in)
1923
58.2 mm (2.3 in)
1924
66.8 mm (2.6 in)
1925
54.6 mm (2.1 in)
1926
66.0 mm (2.6 in)
1927
81.3 mm (3.2 in)
1928
81.3 mm (3.2 in)
1929
55.9 mm (2.2 in)
1930
49.8 mm (2.0 in)
1931
79.5 mm (3.1 in)
1932
65.3 mm (2.6 in)
1933
71.6 mm (2.8 in)
1934
106.7 mm (4.2 in)
1935
95.3 mm (3.8 in)
1936
49.5 mm (1.9 in)
1937
55.9 mm (2.2 in)
1938
104.4 mm (4.1 in)
1939
81.3 mm (3.2 in)
1940
49.5 mm (1.9 in)
1941
68.8 mm (2.7 in)
1942
90.9 mm (3.6 in)
1943
58.9 mm (2.3 in)
1944
82.6 mm (3.3 in)
1945
65.3 mm (2.6 in)
1946
128.3 mm (5.1 in)
1947
43.2 mm (1.7 in)
1948
115.3 mm (4.5 in)
1949
78.2 mm (3.1 in)
1950
88.4 mm (3.5 in)
1951
98.0 mm (3.9 in)
1952
43.2 mm (1.7 in)
1953
31.5 mm (1.2 in)
1954
43.4 mm (1.7 in)
1955
54.6 mm (2.1 in)
1956
73.7 mm (2.9 in)
1957
192.0 mm (7.6 in)
1958
105.2 mm (4.1 in)
1959
67.1 mm (2.6 in)
1960
43.4 mm (1.7 in)
1961
71.1 mm (2.8 in)
1962
60.5 mm (2.4 in)
1963
39.1 mm (1.5 in)
1964
69.1 mm (2.7 in)
1965
58.2 mm (2.3 in)
1966
50.3 mm (2.0 in)
1967
46.7 mm (1.8 in)
1968
51.6 mm (2.0 in)
1969
50.0 mm (2.0 in)
1970
90.2 mm (3.6 in)
1971
40.6 mm (1.6 in)
1972
75.4 mm (3.0 in)
1973
61.0 mm (2.4 in)
1974
54.9 mm (2.2 in)
1975
54.6 mm (2.1 in)
1976
48.0 mm (1.9 in)
1977
64.0 mm (2.5 in)
1978
54.6 mm (2.1 in)
1979
76.7 mm (3.0 in)
1980
77.2 mm (3.0 in)
1981
75.7 mm (3.0 in)
1982
88.1 mm (3.5 in)
1983
64.3 mm (2.5 in)
1984
81.0 mm (3.2 in)
1985
63.8 mm (2.5 in)
1986
74.9 mm (2.9 in)
1987
57.4 mm (2.3 in)
1988
61.0 mm (2.4 in)
1989
44.5 mm (1.8 in)
1990
74.7 mm (2.9 in)
1991
82.0 mm (3.2 in)
1992
37.1 mm (1.5 in)
1993
120.7 mm (4.8 in)
1994
64.0 mm (2.5 in)
1995
71.6 mm (2.8 in)
1996
110.5 mm (4.4 in)
1997
63.2 mm (2.5 in)
1998
71.9 mm (2.8 in)
1999
60.2 mm (2.4 in)
2000
66.3 mm (2.6 in)
2001
47.2 mm (1.9 in)
2002
53.8 mm (2.1 in)
2003
69.9 mm (2.8 in)
2004
83.8 mm (3.3 in)
2005
77.7 mm (3.1 in)
2006
107.7 mm (4.2 in)
2007
53.8 mm (2.1 in)
2008
105.9 mm (4.2 in)
2009
44.5 mm (1.8 in)
Wettest five days (Rx5day)
The wettest five days of the year at Union, 1916 to 2009. The record is 282.8 mm (11.1 in) in 1957, marked on the chart; the median year is 100.1 mm (3.9 in).
Wettest five days (Rx5day) at Union by year
Year
Wettest five days (Rx5day)
1916
46.4 mm (1.8 in)
1917
81.5 mm (3.2 in)
1918
163.0 mm (6.4 in)
1919
161.3 mm (6.4 in)
1920
72.9 mm (2.9 in)
1921
96.6 mm (3.8 in)
1922
118.4 mm (4.7 in)
1923
63.6 mm (2.5 in)
1924
97.3 mm (3.8 in)
1925
61.5 mm (2.4 in)
1926
127.2 mm (5.0 in)
1927
121.9 mm (4.8 in)
1928
139.2 mm (5.5 in)
1929
96.8 mm (3.8 in)
1930
62.6 mm (2.5 in)
1931
100.1 mm (3.9 in)
1932
88.9 mm (3.5 in)
1933
147.6 mm (5.8 in)
1934
93.4 mm (3.7 in)
1935
140.7 mm (5.5 in)
1936
64.5 mm (2.5 in)
1937
90.7 mm (3.6 in)
1938
202.5 mm (8.0 in)
1939
86.4 mm (3.4 in)
1940
69.2 mm (2.7 in)
1941
103.1 mm (4.1 in)
1942
115.3 mm (4.5 in)
1943
126.0 mm (5.0 in)
1944
104.7 mm (4.1 in)
1945
130.8 mm (5.1 in)
1946
231.7 mm (9.1 in)
1947
111.3 mm (4.4 in)
1948
118.9 mm (4.7 in)
1949
126.5 mm (5.0 in)
1950
124.9 mm (4.9 in)
1951
98.0 mm (3.9 in)
1952
76.5 mm (3.0 in)
1953
45.7 mm (1.8 in)
1954
64.5 mm (2.5 in)
1955
69.3 mm (2.7 in)
1956
112.3 mm (4.4 in)
1957
282.8 mm (11.1 in)
1958
139.8 mm (5.5 in)
1959
93.5 mm (3.7 in)
1960
48.5 mm (1.9 in)
1961
166.6 mm (6.6 in)
1962
83.3 mm (3.3 in)
1963
59.0 mm (2.3 in)
1964
80.5 mm (3.2 in)
1965
79.8 mm (3.1 in)
1966
130.0 mm (5.1 in)
1967
81.2 mm (3.2 in)
1968
89.4 mm (3.5 in)
1969
97.5 mm (3.8 in)
1970
111.8 mm (4.4 in)
1971
81.2 mm (3.2 in)
1972
107.2 mm (4.2 in)
1973
95.6 mm (3.8 in)
1974
104.5 mm (4.1 in)
1975
82.6 mm (3.3 in)
1976
60.2 mm (2.4 in)
1977
79.8 mm (3.1 in)
1978
79.2 mm (3.1 in)
1979
118.1 mm (4.6 in)
1980
100.1 mm (3.9 in)
1981
118.8 mm (4.7 in)
1982
149.3 mm (5.9 in)
1983
129.5 mm (5.1 in)
1984
130.8 mm (5.1 in)
1985
131.7 mm (5.2 in)
1986
168.1 mm (6.6 in)
1987
88.2 mm (3.5 in)
1988
89.1 mm (3.5 in)
1989
75.5 mm (3.0 in)
1990
108.9 mm (4.3 in)
1991
124.2 mm (4.9 in)
1992
97.9 mm (3.9 in)
1993
190.1 mm (7.5 in)
1994
132.1 mm (5.2 in)
1995
112.8 mm (4.4 in)
1996
146.6 mm (5.8 in)
1997
79.2 mm (3.1 in)
1998
141.8 mm (5.6 in)
1999
75.0 mm (3.0 in)
2000
81.3 mm (3.2 in)
2001
105.6 mm (4.2 in)
2002
89.9 mm (3.5 in)
2003
134.9 mm (5.3 in)
2004
88.9 mm (3.5 in)
2005
150.8 mm (5.9 in)
2006
113.3 mm (4.5 in)
2007
74.1 mm (2.9 in)
2008
157.7 mm (6.2 in)
2009
84.7 mm (3.3 in)
Longest dry spell (CDD)
The longest dry spell of the year at Union, 1916 to 2009. The record is 38 days in 1919, marked on the chart; the median year is 21 days.
Longest dry spell (CDD) at Union by year
Year
Longest dry spell (CDD)
1916
18 days
1917
25 days
1918
21 days
1919
38 days
1920
19 days
1921
13 days
1922
17 days
1923
13 days
1924
22 days
1925
18 days
1926
21 days
1927
18 days
1928
17 days
1929
20 days
1930
29 days
1931
25 days
1932
13 days
1933
29 days
1934
18 days
1935
16 days
1936
27 days
1937
19 days
1938
23 days
1939
20 days
1940
23 days
1941
20 days
1942
25 days
1943
21 days
1944
28 days
1945
26 days
1946
18 days
1947
21 days
1948
20 days
1949
21 days
1950
30 days
1951
14 days
1952
24 days
1953
22 days
1954
19 days
1955
29 days
1956
18 days
1957
22 days
1958
25 days
1959
26 days
1960
17 days
1961
14 days
1962
22 days
1963
35 days
1964
29 days
1965
16 days
1966
21 days
1967
24 days
1968
24 days
1969
20 days
1970
25 days
1971
20 days
1972
15 days
1973
15 days
1974
22 days
1975
11 days
1976
34 days
1977
18 days
1978
20 days
1979
37 days
1980
22 days
1981
19 days
1982
15 days
1983
18 days
1984
36 days
1985
28 days
1986
24 days
1987
26 days
1988
15 days
1989
23 days
1990
19 days
1991
16 days
1992
19 days
1993
17 days
1994
15 days
1995
27 days
1996
21 days
1997
19 days
1998
19 days
1999
20 days
2000
15 days
2001
21 days
2002
21 days
2003
13 days
2004
24 days
2005
21 days
2006
18 days
2007
17 days
2008
17 days
2009
26 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
66 years with a frost
Across 66 years with a frost, the median last spring frost at Union falls on 20 April and the median first autumn frost on 10 October, which leaves a median of 174 days between them.
In 1979 to 2008 the median growing season was 181 days. That is 12 days more than in 1938 to 1972.
Fitted over all years, the growing season changes by +2.4 days per decade at this station.
Frost dates and growing season at Union
Measure
Median, all years
Earliest period (1938 to 1972)
Recent period (1979 to 2008)
Recent against earliest
Fitted trend
Last spring frost
20 April
21 April
17 April
4 days earlier
-1.0 days per decade
First autumn frost
10 October
8 October
11 October
3 days later
+1.4 days per decade
Growing days
174 days
169 days
181 days
12 days more
+2.4 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
88 years, 1917 to 2008
A day with at least 65.9 mm (2.6 in) of rain is expected about once in 2 years. A day with at least 151.6 mm (6.0 in) of rain is expected about once in 100 years.
Rainfall return levels at Union: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
65.9 mm (2.6 in)
5 years
86.3 mm (3.4 in)
10 years
100.7 mm (4.0 in)
25 years
120.2 mm (4.7 in)
50 years
135.5 mm (5.3 in)
100 years
151.6 mm (6.0 in)
Longer than the 88 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, 88 years of values from 1917 to 2008.
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: 192.0 mm (7.6 in) in 1957; 128.3 mm (5.1 in) in 1946; 120.7 mm (4.8 in) in 1993.
Station Changes
2 suspected
2 changes were suspected in the annual mean temperature of Union, at 1946 and 1952. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1946 ran 0.5 C (0.8 F) lower than in the years before (possible change).
Relative to 5 neighbouring stations, the station's annual mean temperature from 1952 ran 0.2 C (0.4 F) higher than in the years before (possible change).
Suspected changes in the annual mean temperature at Union, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1946
-0.4
-0.8
possible
5
1952
+0.2
+0.4
possible
5
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
Download the Data
Data for Union standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Union 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 2026-10-15 (15 October 2026). Records are computed by this site and are not official.