Record envelope, standing records and threshold days for Duncan (CA001012550), British Columbia, Canada, with 32 years of record.
Key Facts for Duncan
Duncan (CA001012550) is a weather station in British Columbia, Canada at 48.78 latitude and -123.72 longitude, 9 m (30 ft) above sea level.
The station reports from 1926 to 1957, 32 years of record.
1,464 records set at Duncan still stand.
Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
Duncan set a daily record precipitation of 25.4 mm (1.0 in) on 25 December 1957.
About the Station
Location: British Columbia, Canada, 48.78 latitude, -123.72 longitude.
Elevation: 9 m (30 ft).
Period of record: 1926 to 1957, 32 years.
Eligible elements: tmax, tmin, prcp, snow.
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 Duncan. 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 Duncan, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
17.2 C (63.0 F)
-20.6 C (-5.1 F)
n/a
n/a
Feb
18.9 C (66.0 F)
-17.2 C (1.0 F)
n/a
n/a
Mar
23.9 C (75.0 F)
-11.7 C (10.9 F)
n/a
n/a
Apr
31.7 C (89.1 F)
-6.7 C (19.9 F)
n/a
n/a
May
35.0 C (95.0 F)
-2.2 C (28.0 F)
n/a
n/a
Jun
37.8 C (100.0 F)
-2.8 C (27.0 F)
n/a
n/a
Jul
41.1 C (106.0 F)
1.1 C (34.0 F)
n/a
n/a
Aug
37.2 C (99.0 F)
2.8 C (37.0 F)
n/a
n/a
Sep
37.8 C (100.0 F)
-5.0 C (23.0 F)
n/a
n/a
Oct
30.6 C (87.1 F)
-8.9 C (16.0 F)
n/a
n/a
Nov
22.8 C (73.0 F)
-15.6 C (3.9 F)
n/a
n/a
Dec
16.7 C (62.1 F)
-16.7 C (1.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Duncan still stand. 1950 holds the most, with 70.
Standing records at Duncan by the year they were set
Year set
Standing records
1926
45
1927
46
1928
51
1929
55
1930
47
1931
40
1932
55
1933
53
1934
57
1935
50
1936
61
1937
37
1938
39
1939
54
1940
53
1941
60
1942
50
1943
42
1944
46
1945
36
1946
36
1947
35
1948
35
1949
43
1950
70
1951
47
1952
37
1953
28
1954
32
1955
48
1956
43
1957
33
All-Time Record Progression
1 new records
1 all-time records were set at Duncan between 20 July 1956 and 20 July 1956. Each dot is a new record.
When Duncan set new all-time records
Date
Kind
Detail
1956-07-20
Record high minimum temperature
Record high minimum temperature 19.4 C (66.9 F)
Wettest Day of Each Month
Nov: 110.2 mm (4.3 in)
The wettest day on record for each calendar month at Duncan. The most was 110.2 mm (4.3 in) on 3 November 1955.
Record daily precipitation for each month at Duncan
Month
Record daily precipitation (mm)
Date
Jan
104.4 mm (4.1 in)
21 January 1935
Feb
48.5 mm (1.9 in)
17 February 1930
Mar
44.5 mm (1.8 in)
12 March 1951
Apr
47.8 mm (1.9 in)
14 April 1937
May
43.4 mm (1.7 in)
28 May 1948
Jun
37.3 mm (1.5 in)
22 June 1955
Jul
21.6 mm (0.9 in)
26 July 1940
Aug
38.9 mm (1.5 in)
30 August 1937
Sep
38.1 mm (1.5 in)
29 September 1953
Oct
62.0 mm (2.4 in)
19 October 1956
Nov
110.2 mm (4.3 in)
3 November 1955
Dec
76.2 mm (3.0 in)
28 December 1937
Period of Record Coverage
1926 to 1957
Complete yearUnder 90 percent of days
32 years of record at Duncan, 1926 to 1957. 2 years have data for under 90 percent of days and are left out of rankings: 1926, 1957.
Cooler than the station meanWarmer than the station mean
One stripe for each of 30 complete years at Duncan, 1927 to 1956. Blue stripes are years cooler than the station's own mean of 10.3 C (50.5 F); red stripes are warmer. The coolest year was 1950, at 9.1 C (48.4 F), and the warmest was 1940, at 11.7 C (53.0 F). The strongest colour marks a difference of 1.5 C (2.7 F).
Annual mean temperature at Duncan as warming stripes, 1927 to 1956
Year
Annual mean temperature
Difference from the station mean
1927
9.6 C
-0.73 C
1928
10.5 C
+0.20 C
1929
9.2 C
-1.09 C
1930
9.4 C
-0.86 C
1931
10.5 C
+0.25 C
1932
10.1 C
-0.22 C
1933
9.7 C
-0.58 C
1934
11.3 C
+0.97 C
1935
10.2 C
-0.09 C
1936
10.7 C
+0.39 C
1937
10.5 C
+0.22 C
1938
10.8 C
+0.50 C
1939
11.1 C
+0.79 C
1940
11.7 C
+1.41 C
1941
11.5 C
+1.26 C
1942
11.0 C
+0.75 C
1943
10.4 C
+0.10 C
1944
10.8 C
+0.54 C
1945
10.3 C
+0.05 C
1946
10.2 C
-0.07 C
1947
10.6 C
+0.32 C
1948
9.6 C
-0.73 C
1949
9.5 C
-0.81 C
1950
9.1 C
-1.19 C
1951
9.6 C
-0.66 C
1952
9.9 C
-0.36 C
1953
10.6 C
+0.34 C
1954
10.1 C
-0.15 C
1955
9.5 C
-0.77 C
1956
10.6 C
+0.28 C
The fitted trend in annual mean temperature here over 1927 to 1956 is -0.1 C (-0.4 to 0.2) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.1 F (-0.6 to 0.4) per decade. The slope is a straight line fitted to 30 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Duncan
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.1 C (-0.4 to 0.2) per decade
-0.1 F (-0.6 to 0.4) per decade
1927 to 1956
30
Not clearly different from zero
Mean daily maximum
-0.38 C (-0.79 to 0.04) per decade
-0.7 F (-1.4 to 0.1) per decade
1927 to 1956
30
Not clearly different from zero
Mean daily minimum
0.27 C (0.03 to 0.52) per decade
0.49 F (0.05 to 0.93) per decade
1927 to 1956
30
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
1926 to 1957
Yearly extremes at Duncan: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
41.1 C (106.0 F)
1941
35.0 C (95.0 F)
32
Coldest night (TNn)
-20.6 C (-5.1 F)
1950
-12.5 C (9.5 F)
32
Wettest day (Rx1day)
110.2 mm (4.3 in)
1955
44.1 mm (1.7 in)
32
Wettest five days (Rx5day)
273.3 mm (10.8 in)
1935
95.4 mm (3.8 in)
32
Longest dry spell (CDD)
74 days
1942
30 days
32
Hottest day (TXx)
The hottest day of the year at Duncan, 1926 to 1957. The record is 41.1 C (106.0 F) in 1941, marked on the chart; the median year is 35.0 C (95.0 F).
Hottest day (TXx) at Duncan by year
Year
Hottest day (TXx)
1926
29.4 C (84.9 F)
1927
35.6 C (96.1 F)
1928
34.4 C (93.9 F)
1929
32.2 C (90.0 F)
1930
32.2 C (90.0 F)
1931
34.4 C (93.9 F)
1932
33.3 C (91.9 F)
1933
36.1 C (97.0 F)
1934
36.1 C (97.0 F)
1935
36.1 C (97.0 F)
1936
33.9 C (93.0 F)
1937
35.6 C (96.1 F)
1938
36.1 C (97.0 F)
1939
36.1 C (97.0 F)
1940
35.0 C (95.0 F)
1941
41.1 C (106.0 F)
1942
38.9 C (102.0 F)
1943
33.3 C (91.9 F)
1944
38.9 C (102.0 F)
1945
36.1 C (97.0 F)
1946
35.0 C (95.0 F)
1947
35.0 C (95.0 F)
1948
33.3 C (91.9 F)
1949
30.6 C (87.1 F)
1950
32.8 C (91.0 F)
1951
35.0 C (95.0 F)
1952
36.1 C (97.0 F)
1953
32.2 C (90.0 F)
1954
31.7 C (89.1 F)
1955
37.8 C (100.0 F)
1956
39.4 C (102.9 F)
1957
33.9 C (93.0 F)
Coldest night (TNn)
The coldest night of the year at Duncan, 1926 to 1957. The record is -20.6 C (-5.1 F) in 1950, marked on the chart; the median year is -12.5 C (9.5 F).
Coldest night (TNn) at Duncan by year
Year
Coldest night (TNn)
1926
-12.2 C (10.0 F)
1927
-16.7 C (1.9 F)
1928
-7.2 C (19.0 F)
1929
-18.9 C (-2.0 F)
1930
-15.6 C (3.9 F)
1931
-7.2 C (19.0 F)
1932
-13.3 C (8.1 F)
1933
-13.3 C (8.1 F)
1934
-6.1 C (21.0 F)
1935
-16.7 C (1.9 F)
1936
-15.0 C (5.0 F)
1937
-16.7 C (1.9 F)
1938
-8.9 C (16.0 F)
1939
-7.8 C (18.0 F)
1940
-9.4 C (15.1 F)
1941
-12.2 C (10.0 F)
1942
-12.8 C (9.0 F)
1943
-12.8 C (9.0 F)
1944
-10.6 C (12.9 F)
1945
-7.2 C (19.0 F)
1946
-8.3 C (17.1 F)
1947
-13.9 C (7.0 F)
1948
-12.2 C (10.0 F)
1949
-16.7 C (1.9 F)
1950
-20.6 C (-5.1 F)
1951
-12.8 C (9.0 F)
1952
-11.7 C (10.9 F)
1953
-3.9 C (25.0 F)
1954
-11.7 C (10.9 F)
1955
-15.6 C (3.9 F)
1956
-10.0 C (14.0 F)
1957
-16.7 C (1.9 F)
Wettest day (Rx1day)
The wettest day of the year at Duncan, 1926 to 1957. The record is 110.2 mm (4.3 in) in 1955, marked on the chart; the median year is 44.1 mm (1.7 in).
Wettest day (Rx1day) at Duncan by year
Year
Wettest day (Rx1day)
1926
42.2 mm (1.7 in)
1927
33.0 mm (1.3 in)
1928
27.9 mm (1.1 in)
1929
31.8 mm (1.3 in)
1930
48.5 mm (1.9 in)
1931
45.2 mm (1.8 in)
1932
39.1 mm (1.5 in)
1933
49.8 mm (2.0 in)
1934
64.5 mm (2.5 in)
1935
104.4 mm (4.1 in)
1936
47.0 mm (1.9 in)
1937
76.2 mm (3.0 in)
1938
52.8 mm (2.1 in)
1939
69.9 mm (2.8 in)
1940
47.8 mm (1.9 in)
1941
63.8 mm (2.5 in)
1942
40.6 mm (1.6 in)
1943
43.2 mm (1.7 in)
1944
41.4 mm (1.6 in)
1945
42.9 mm (1.7 in)
1946
34.8 mm (1.4 in)
1947
47.2 mm (1.9 in)
1948
43.4 mm (1.7 in)
1949
43.7 mm (1.7 in)
1950
38.1 mm (1.5 in)
1951
44.5 mm (1.8 in)
1952
33.5 mm (1.3 in)
1953
38.1 mm (1.5 in)
1954
67.3 mm (2.6 in)
1955
110.2 mm (4.3 in)
1956
69.6 mm (2.7 in)
1957
30.7 mm (1.2 in)
Wettest five days (Rx5day)
The wettest five days of the year at Duncan, 1926 to 1957. The record is 273.3 mm (10.8 in) in 1935, marked on the chart; the median year is 95.4 mm (3.8 in).
Wettest five days (Rx5day) at Duncan by year
Year
Wettest five days (Rx5day)
1926
89.1 mm (3.5 in)
1927
99.6 mm (3.9 in)
1928
75.2 mm (3.0 in)
1929
58.9 mm (2.3 in)
1930
96.0 mm (3.8 in)
1931
79.0 mm (3.1 in)
1932
82.8 mm (3.3 in)
1933
139.8 mm (5.5 in)
1934
118.1 mm (4.6 in)
1935
273.3 mm (10.8 in)
1936
89.6 mm (3.5 in)
1937
151.6 mm (6.0 in)
1938
117.4 mm (4.6 in)
1939
190.8 mm (7.5 in)
1940
86.6 mm (3.4 in)
1941
95.6 mm (3.8 in)
1942
74.7 mm (2.9 in)
1943
74.1 mm (2.9 in)
1944
91.5 mm (3.6 in)
1945
85.1 mm (3.4 in)
1946
70.6 mm (2.8 in)
1947
118.0 mm (4.6 in)
1948
122.4 mm (4.8 in)
1949
96.3 mm (3.8 in)
1950
82.1 mm (3.2 in)
1951
95.2 mm (3.7 in)
1952
68.4 mm (2.7 in)
1953
131.9 mm (5.2 in)
1954
194.3 mm (7.6 in)
1955
142.8 mm (5.6 in)
1956
115.3 mm (4.5 in)
1957
90.2 mm (3.6 in)
Longest dry spell (CDD)
The longest dry spell of the year at Duncan, 1926 to 1957. The record is 74 days in 1942, marked on the chart; the median year is 30 days.
Longest dry spell (CDD) at Duncan by year
Year
Longest dry spell (CDD)
1926
15 days
1927
30 days
1928
24 days
1929
28 days
1930
23 days
1931
28 days
1932
29 days
1933
29 days
1934
34 days
1935
24 days
1936
39 days
1937
43 days
1938
35 days
1939
37 days
1940
33 days
1941
31 days
1942
74 days
1943
28 days
1944
49 days
1945
31 days
1946
22 days
1947
24 days
1948
16 days
1949
20 days
1950
30 days
1951
61 days
1952
41 days
1953
35 days
1954
24 days
1955
43 days
1956
32 days
1957
19 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
30 years with a frost
Across 30 years with a frost, the median last spring frost at Duncan falls on 2 May and the median first autumn frost on 10 October, which leaves a median of 163 days between them.
Fitted over all years, the growing season changes by +4.2 days per decade at this station.
Frost dates and growing season at Duncan
Measure
Median, all years
Earliest period
Recent period (1927 to 1956)
Recent against earliest
Fitted trend
Last spring frost
2 May
n/a
2 May
n/a
+0.5 days per decade
First autumn frost
10 October
n/a
10 October
n/a
+4.6 days per decade
Growing days
163 days
n/a
163 days
n/a
+4.2 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
31 years, 1927 to 1957
A day with at least 45.1 mm (1.8 in) of rain is expected about once in 2 years. A day with at least 133.8 mm (5.3 in) of rain is expected about once in 100 years.
Rainfall return levels at Duncan: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
45.1 mm (1.8 in)
5 years
60.7 mm (2.4 in)
10 years
73.7 mm (2.9 in)
25 years
93.9 mm (3.7 in)
50 years
112.3 mm (4.4 in)
Longer than the 31 years of record
100 years
133.8 mm (5.3 in)
Longer than the 31 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, 31 years of values from 1927 to 1957.
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: 110.2 mm (4.3 in) in 1955; 104.4 mm (4.1 in) in 1935; 76.2 mm (3.0 in) in 1937.
Download the Data
Data for Duncan standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Duncan 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.