Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Barrage Mercier. 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 Barrage Mercier, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
12.8 C (55.0 F)
-41.7 C (-43.1 F)
n/a
n/a
Feb
13.3 C (55.9 F)
-42.2 C (-44.0 F)
n/a
n/a
Mar
22.8 C (73.0 F)
-36.7 C (-34.1 F)
n/a
n/a
Apr
30.0 C (86.0 F)
-21.7 C (-7.1 F)
n/a
n/a
May
34.4 C (93.9 F)
-9.4 C (15.1 F)
n/a
n/a
Jun
35.6 C (96.1 F)
-2.2 C (28.0 F)
n/a
n/a
Jul
36.7 C (98.1 F)
0.6 C (33.1 F)
n/a
n/a
Aug
36.7 C (98.1 F)
-1.1 C (30.0 F)
n/a
n/a
Sep
34.4 C (93.9 F)
-6.1 C (21.0 F)
n/a
n/a
Oct
27.8 C (82.0 F)
-12.0 C (10.4 F)
n/a
n/a
Nov
18.9 C (66.0 F)
-28.0 C (-18.4 F)
n/a
n/a
Dec
12.2 C (54.0 F)
-40.0 C (-40.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Barrage Mercier still stand. 1933 holds the most, with 42.
Standing records at Barrage Mercier by the year they were set
Year set
Standing records
1927
30
1928
22
1929
34
1930
37
1931
38
1932
33
1933
42
1934
39
1935
15
1936
37
1937
21
1938
23
1939
11
1940
29
1941
20
1942
29
1943
26
1944
19
1945
24
1946
38
1947
41
1948
25
1949
40
1950
39
1951
35
1952
19
1953
30
1954
26
1955
23
1956
23
1957
33
1958
22
1959
28
1960
19
1961
23
1962
26
1963
25
1964
29
1965
34
1966
29
1967
16
1968
31
1969
24
1970
22
1971
25
1972
20
1973
24
1974
11
1975
28
1976
24
1977
34
1978
22
1979
40
1980
7
All-Time Record Progression
2 new records
2 all-time records were set at Barrage Mercier between 14 January 1957 and 26 August 1961. Each dot is a new record.
When Barrage Mercier set new all-time records
Date
Kind
Detail
1957-01-14
Record low maximum temperature
Record low maximum temperature -31.7 C (-25.1 F)
1961-08-26
Record daily precipitation
Record daily precipitation 78.0 mm (3.1 in)
Wettest Day of Each Month
Aug: 78.0 mm (3.1 in)
The wettest day on record for each calendar month at Barrage Mercier. The most was 78.0 mm (3.1 in) on 26 August 1961.
Record daily precipitation for each month at Barrage Mercier
Month
Record daily precipitation (mm)
Date
Jan
26.2 mm (1.0 in)
25 January 1975
Feb
36.8 mm (1.4 in)
12 February 1932
Mar
62.0 mm (2.4 in)
18 March 1936
Apr
50.8 mm (2.0 in)
11 April 1947
May
43.7 mm (1.7 in)
25 May 1947
Jun
61.5 mm (2.4 in)
16 June 1974
Jul
70.6 mm (2.8 in)
25 July 1979
Aug
78.0 mm (3.1 in)
26 August 1961
Sep
67.3 mm (2.6 in)
22 September 1931
Oct
49.5 mm (1.9 in)
12 October 1946
Nov
52.6 mm (2.1 in)
15 November 1956
Dec
50.8 mm (2.0 in)
4 December 1955
Period of Record Coverage
1927 to 1980
Complete yearUnder 90 percent of days
54 years of record at Barrage Mercier, 1927 to 1980. 3 years have data for under 90 percent of days and are left out of rankings: 1945, 1976, 1980.
Cooler than the station meanWarmer than the station mean
One stripe for each of 48 complete years at Barrage Mercier, 1927 to 1978. Blue stripes are years cooler than the station's own mean of 3.6 C (38.5 F); red stripes are warmer. The coolest year was 1972, at 2.2 C (36.0 F), and the warmest was 1931, at 5.8 C (42.4 F). The strongest colour marks a difference of 2.2 C (4.0 F).
Annual mean temperature at Barrage Mercier as warming stripes, 1927 to 1978
Year
Annual mean temperature
Difference from the station mean
1927
4.7 C
+1.14 C
1928
3.7 C
+0.10 C
1929
3.4 C
-0.24 C
1930
4.4 C
+0.84 C
1931
5.8 C
+2.20 C
1932
4.6 C
+0.96 C
1933
3.8 C
+0.21 C
1934
2.9 C
-0.70 C
1935
2.8 C
-0.84 C
1936
2.6 C
-1.04 C
1937
4.8 C
+1.23 C
1938
4.1 C
+0.46 C
1939
3.2 C
-0.37 C
1941
4.0 C
+0.42 C
1942
4.2 C
+0.62 C
1943
2.4 C
-1.15 C
1944
4.2 C
+0.56 C
1946
2.3 C
-1.32 C
1947
2.7 C
-0.90 C
1948
3.7 C
+0.06 C
1949
3.8 C
+0.23 C
1950
2.7 C
-0.87 C
1951
3.3 C
-0.33 C
1952
4.2 C
+0.62 C
1953
4.9 C
+1.32 C
1954
3.1 C
-0.46 C
1955
3.8 C
+0.18 C
1956
2.7 C
-0.92 C
1957
3.5 C
-0.13 C
1958
2.8 C
-0.75 C
1959
3.6 C
0.00 C
1960
3.9 C
+0.31 C
1961
4.2 C
+0.57 C
1962
3.4 C
-0.24 C
1963
3.0 C
-0.59 C
1964
4.0 C
+0.43 C
1965
2.8 C
-0.82 C
1966
3.8 C
+0.19 C
1967
2.8 C
-0.80 C
1968
3.5 C
-0.05 C
1969
4.0 C
+0.38 C
1970
3.2 C
-0.40 C
1972
2.2 C
-1.35 C
1973
4.7 C
+1.07 C
1974
3.1 C
-0.51 C
1975
4.3 C
+0.67 C
1977
4.2 C
+0.61 C
1978
3.0 C
-0.58 C
The fitted trend in annual mean temperature here over 1927 to 1978 is -0.1 C (-0.3 to 0.1) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.2 F (-0.5 to 0.1) per decade. The slope is a straight line fitted to 48 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Barrage Mercier
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.1 C (-0.3 to 0.1) per decade
-0.2 F (-0.5 to 0.1) per decade
1927 to 1978
48
Not clearly different from zero
Mean daily maximum
-0.02 C (-0.18 to 0.13) per decade
-0.04 F (-0.32 to 0.24) per decade
1927 to 1978
48
Not clearly different from zero
Mean daily minimum
-0.18 C (-0.36 to 0.01) per decade
-0.32 F (-0.66 to 0.02) per decade
1927 to 1978
48
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
1927 to 1980
Yearly extremes at Barrage Mercier: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
36.7 C (98.1 F)
1937
32.8 C (91.0 F)
54
Coldest night (TNn)
-42.2 C (-44.0 F)
1951
-36.1 C (-33.0 F)
54
Wettest day (Rx1day)
78.0 mm (3.1 in)
1961
39.1 mm (1.5 in)
54
Wettest five days (Rx5day)
131.4 mm (5.2 in)
1939
64.4 mm (2.5 in)
54
Longest dry spell (CDD)
31 days
1958
13 days
54
Hottest day (TXx)
The hottest day of the year at Barrage Mercier, 1927 to 1980. The record is 36.7 C (98.1 F) in 1937, marked on the chart; the median year is 32.8 C (91.0 F).
Hottest day (TXx) at Barrage Mercier by year
Year
Hottest day (TXx)
1927
33.9 C (93.0 F)
1928
33.3 C (91.9 F)
1929
34.4 C (93.9 F)
1930
31.1 C (88.0 F)
1931
35.6 C (96.1 F)
1932
32.2 C (90.0 F)
1933
33.3 C (91.9 F)
1934
32.8 C (91.0 F)
1935
31.7 C (89.1 F)
1936
32.2 C (90.0 F)
1937
36.7 C (98.1 F)
1938
32.2 C (90.0 F)
1939
32.2 C (90.0 F)
1940
32.8 C (91.0 F)
1941
33.9 C (93.0 F)
1942
30.6 C (87.1 F)
1943
31.1 C (88.0 F)
1944
35.6 C (96.1 F)
1945
30.6 C (87.1 F)
1946
32.2 C (90.0 F)
1947
35.0 C (95.0 F)
1948
35.0 C (95.0 F)
1949
33.9 C (93.0 F)
1950
32.2 C (90.0 F)
1951
30.0 C (86.0 F)
1952
32.8 C (91.0 F)
1953
35.0 C (95.0 F)
1954
28.3 C (82.9 F)
1955
34.4 C (93.9 F)
1956
33.3 C (91.9 F)
1957
32.8 C (91.0 F)
1958
30.0 C (86.0 F)
1959
32.2 C (90.0 F)
1960
31.1 C (88.0 F)
1961
30.6 C (87.1 F)
1962
33.9 C (93.0 F)
1963
35.0 C (95.0 F)
1964
33.9 C (93.0 F)
1965
30.0 C (86.0 F)
1966
32.8 C (91.0 F)
1967
31.7 C (89.1 F)
1968
33.3 C (91.9 F)
1969
33.3 C (91.9 F)
1970
31.7 C (89.1 F)
1971
33.3 C (91.9 F)
1972
30.6 C (87.1 F)
1973
32.8 C (91.0 F)
1974
30.6 C (87.1 F)
1975
36.7 C (98.1 F)
1976
31.7 C (89.1 F)
1977
36.7 C (98.1 F)
1978
33.3 C (91.9 F)
1979
31.7 C (89.1 F)
1980
28.5 C (83.3 F)
Coldest night (TNn)
The coldest night of the year at Barrage Mercier, 1927 to 1980. The record is -42.2 C (-44.0 F) in 1951, marked on the chart; the median year is -36.1 C (-33.0 F).
Coldest night (TNn) at Barrage Mercier by year
Year
Coldest night (TNn)
1927
-35.6 C (-32.1 F)
1928
-37.8 C (-36.0 F)
1929
-37.8 C (-36.0 F)
1930
-33.3 C (-27.9 F)
1931
-27.8 C (-18.0 F)
1932
-33.3 C (-27.9 F)
1933
-38.3 C (-36.9 F)
1934
-38.9 C (-38.0 F)
1935
-36.1 C (-33.0 F)
1936
-31.1 C (-24.0 F)
1937
-31.7 C (-25.1 F)
1938
-36.7 C (-34.1 F)
1939
-31.7 C (-25.1 F)
1940
-32.2 C (-26.0 F)
1941
-32.8 C (-27.0 F)
1942
-37.2 C (-35.0 F)
1943
-38.9 C (-38.0 F)
1944
-32.2 C (-26.0 F)
1945
-33.3 C (-27.9 F)
1946
-40.0 C (-40.0 F)
1947
-40.0 C (-40.0 F)
1948
-36.1 C (-33.0 F)
1949
-32.8 C (-27.0 F)
1950
-35.6 C (-32.1 F)
1951
-42.2 C (-44.0 F)
1952
-41.1 C (-42.0 F)
1953
-33.9 C (-29.0 F)
1954
-40.0 C (-40.0 F)
1955
-38.3 C (-36.9 F)
1956
-31.1 C (-24.0 F)
1957
-41.7 C (-43.1 F)
1958
-35.0 C (-31.0 F)
1959
-36.1 C (-33.0 F)
1960
-33.9 C (-29.0 F)
1961
-34.4 C (-29.9 F)
1962
-40.0 C (-40.0 F)
1963
-40.6 C (-41.1 F)
1964
-34.4 C (-29.9 F)
1965
-37.8 C (-36.0 F)
1966
-36.1 C (-33.0 F)
1967
-40.0 C (-40.0 F)
1968
-38.9 C (-38.0 F)
1969
-32.2 C (-26.0 F)
1970
-38.9 C (-38.0 F)
1971
-36.7 C (-34.1 F)
1972
-40.6 C (-41.1 F)
1973
-36.1 C (-33.0 F)
1974
-35.0 C (-31.0 F)
1975
-34.4 C (-29.9 F)
1976
-37.8 C (-36.0 F)
1977
-38.0 C (-36.4 F)
1978
-34.0 C (-29.2 F)
1979
-42.0 C (-43.6 F)
1980
-31.0 C (-23.8 F)
Wettest day (Rx1day)
The wettest day of the year at Barrage Mercier, 1927 to 1980. The record is 78.0 mm (3.1 in) in 1961, marked on the chart; the median year is 39.1 mm (1.5 in).
Wettest day (Rx1day) at Barrage Mercier by year
Year
Wettest day (Rx1day)
1927
34.0 mm (1.3 in)
1928
49.8 mm (2.0 in)
1929
20.3 mm (0.8 in)
1930
38.1 mm (1.5 in)
1931
67.3 mm (2.6 in)
1932
36.8 mm (1.4 in)
1933
69.1 mm (2.7 in)
1934
26.7 mm (1.1 in)
1935
41.9 mm (1.6 in)
1936
62.0 mm (2.4 in)
1937
41.4 mm (1.6 in)
1938
36.1 mm (1.4 in)
1939
70.1 mm (2.8 in)
1940
50.3 mm (2.0 in)
1941
39.1 mm (1.5 in)
1942
39.1 mm (1.5 in)
1943
70.4 mm (2.8 in)
1944
37.8 mm (1.5 in)
1945
34.3 mm (1.4 in)
1946
59.7 mm (2.4 in)
1947
50.8 mm (2.0 in)
1948
30.2 mm (1.2 in)
1949
34.8 mm (1.4 in)
1950
34.5 mm (1.4 in)
1951
44.2 mm (1.7 in)
1952
52.8 mm (2.1 in)
1953
52.6 mm (2.1 in)
1954
31.2 mm (1.2 in)
1955
51.3 mm (2.0 in)
1956
52.6 mm (2.1 in)
1957
50.8 mm (2.0 in)
1958
40.6 mm (1.6 in)
1959
46.2 mm (1.8 in)
1960
28.2 mm (1.1 in)
1961
78.0 mm (3.1 in)
1962
27.9 mm (1.1 in)
1963
30.7 mm (1.2 in)
1964
32.5 mm (1.3 in)
1965
65.0 mm (2.6 in)
1966
34.8 mm (1.4 in)
1967
55.4 mm (2.2 in)
1968
28.7 mm (1.1 in)
1969
33.0 mm (1.3 in)
1970
49.8 mm (2.0 in)
1971
36.1 mm (1.4 in)
1972
36.1 mm (1.4 in)
1973
51.8 mm (2.0 in)
1974
61.5 mm (2.4 in)
1975
34.3 mm (1.4 in)
1976
33.3 mm (1.3 in)
1977
37.8 mm (1.5 in)
1978
31.0 mm (1.2 in)
1979
70.6 mm (2.8 in)
1980
25.6 mm (1.0 in)
Wettest five days (Rx5day)
The wettest five days of the year at Barrage Mercier, 1927 to 1980. The record is 131.4 mm (5.2 in) in 1939, marked on the chart; the median year is 64.4 mm (2.5 in).
Wettest five days (Rx5day) at Barrage Mercier by year
Year
Wettest five days (Rx5day)
1927
75.6 mm (3.0 in)
1928
68.3 mm (2.7 in)
1929
36.3 mm (1.4 in)
1930
56.2 mm (2.2 in)
1931
90.5 mm (3.6 in)
1932
55.9 mm (2.2 in)
1933
102.7 mm (4.0 in)
1934
47.3 mm (1.9 in)
1935
61.7 mm (2.4 in)
1936
87.9 mm (3.5 in)
1937
56.9 mm (2.2 in)
1938
75.0 mm (3.0 in)
1939
131.4 mm (5.2 in)
1940
59.4 mm (2.3 in)
1941
65.3 mm (2.6 in)
1942
69.4 mm (2.7 in)
1943
71.2 mm (2.8 in)
1944
62.2 mm (2.4 in)
1945
62.5 mm (2.5 in)
1946
76.5 mm (3.0 in)
1947
74.7 mm (2.9 in)
1948
63.5 mm (2.5 in)
1949
62.5 mm (2.5 in)
1950
52.1 mm (2.1 in)
1951
58.2 mm (2.3 in)
1952
78.5 mm (3.1 in)
1953
61.3 mm (2.4 in)
1954
60.8 mm (2.4 in)
1955
76.9 mm (3.0 in)
1956
96.3 mm (3.8 in)
1957
83.8 mm (3.3 in)
1958
68.1 mm (2.7 in)
1959
46.2 mm (1.8 in)
1960
46.5 mm (1.8 in)
1961
95.1 mm (3.7 in)
1962
44.4 mm (1.7 in)
1963
51.8 mm (2.0 in)
1964
61.8 mm (2.4 in)
1965
90.4 mm (3.6 in)
1966
49.8 mm (2.0 in)
1967
87.7 mm (3.5 in)
1968
63.1 mm (2.5 in)
1969
48.7 mm (1.9 in)
1970
78.3 mm (3.1 in)
1971
49.8 mm (2.0 in)
1972
84.7 mm (3.3 in)
1973
73.4 mm (2.9 in)
1974
84.1 mm (3.3 in)
1975
66.6 mm (2.6 in)
1976
47.0 mm (1.9 in)
1977
74.4 mm (2.9 in)
1978
45.0 mm (1.8 in)
1979
110.5 mm (4.4 in)
1980
36.8 mm (1.4 in)
Longest dry spell (CDD)
The longest dry spell of the year at Barrage Mercier, 1927 to 1980. The record is 31 days in 1958, marked on the chart; the median year is 13 days.
Longest dry spell (CDD) at Barrage Mercier by year
Year
Longest dry spell (CDD)
1927
21 days
1928
10 days
1929
10 days
1930
18 days
1931
11 days
1932
18 days
1933
12 days
1934
13 days
1935
20 days
1936
10 days
1937
14 days
1938
10 days
1939
20 days
1940
13 days
1941
18 days
1942
13 days
1943
18 days
1944
17 days
1945
13 days
1946
11 days
1947
17 days
1948
12 days
1949
18 days
1950
10 days
1951
10 days
1952
13 days
1953
14 days
1954
11 days
1955
16 days
1956
12 days
1957
18 days
1958
31 days
1959
12 days
1960
19 days
1961
24 days
1962
14 days
1963
20 days
1964
13 days
1965
18 days
1966
10 days
1967
16 days
1968
13 days
1969
12 days
1970
17 days
1971
12 days
1972
13 days
1973
15 days
1974
12 days
1975
18 days
1976
11 days
1977
12 days
1978
18 days
1979
13 days
1980
20 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
48 years with a frost
Across 48 years with a frost, the median last spring frost at Barrage Mercier falls on 24 May and the median first autumn frost on 15 September, which leaves a median of 117 days between them.
Fitted over all years, the growing season changes by -1.9 days per decade at this station.
Frost dates and growing season at Barrage Mercier
Measure
Median, all years
Earliest period
Recent period (1947 to 1978)
Recent against earliest
Fitted trend
Last spring frost
24 May
n/a
27 May
n/a
+0.6 days per decade
First autumn frost
15 September
n/a
14 September
n/a
-1.4 days per decade
Growing days
117 days
n/a
109 days
n/a
-1.9 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
51 years, 1927 to 1979
A day with at least 42.5 mm (1.7 in) of rain is expected about once in 2 years. A day with at least 90.0 mm (3.5 in) of rain is expected about once in 100 years.
Rainfall return levels at Barrage Mercier: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
42.5 mm (1.7 in)
5 years
55.5 mm (2.2 in)
10 years
63.9 mm (2.5 in)
25 years
74.6 mm (2.9 in)
50 years
82.4 mm (3.2 in)
100 years
90.0 mm (3.5 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 1927 to 1979.
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: 78.0 mm (3.1 in) in 1961; 70.6 mm (2.8 in) in 1979; 70.4 mm (2.8 in) in 1943.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Download the Data
Data for Barrage Mercier standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Barrage Mercier 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.