Ottawa Macdonald-Cartier Int'l Weather Records (CA006106000)
Record envelope, standing records and threshold days for Ottawa Macdonald-Cartier Int'l (CA006106000), Ontario, Canada, with 74 years of record.
Key Facts for Ottawa Macdonald-Cartier Int'l
- Ottawa Macdonald-Cartier Int'l (CA006106000) is a weather station in Ontario, Canada at 45.32 latitude and -75.67 longitude, 114 m (374 ft) above sea level.
- The station reports from 1938 to 2011, 74 years of record.
- 1,464 records set at Ottawa Macdonald-Cartier Int'l still stand.
- Records are tracked for tmax, tmin, prcp, snow: an element needs 30 years of data to be eligible.
- Ottawa Macdonald-Cartier Int'l set a daily record precipitation of 14.8 mm (0.6 in) on 22 December 1983.
About the Station
- Location: Ontario, Canada, 45.32 latitude, -75.67 longitude.
- Elevation: 114 m (374 ft).
- Period of record: 1938 to 2011, 74 years.
- Eligible elements: tmax, tmin, prcp, snow.
Daily Record Envelope and 2026
0 days at or beyond a record| Month | Highest record high | Lowest record low | 2026 highest maximum | 2026 lowest minimum |
|---|---|---|---|---|
| Jan | 11.1 C (52.0 F) | -35.6 C (-32.1 F) | n/a | n/a |
| Feb | 12.0 C (53.6 F) | -36.1 C (-33.0 F) | n/a | n/a |
| Mar | 26.7 C (80.1 F) | -30.6 C (-23.1 F) | n/a | n/a |
| Apr | 30.0 C (86.0 F) | -16.7 C (1.9 F) | n/a | n/a |
| May | 32.8 C (91.0 F) | -5.6 C (21.9 F) | n/a | n/a |
| Jun | 36.1 C (97.0 F) | -0.1 C (31.8 F) | n/a | n/a |
| Jul | 36.7 C (98.1 F) | 5.0 C (41.0 F) | n/a | n/a |
| Aug | 37.8 C (100.0 F) | 2.8 C (37.0 F) | n/a | n/a |
| Sep | 35.0 C (95.0 F) | -3.0 C (26.6 F) | n/a | n/a |
| Oct | 27.8 C (82.0 F) | -7.8 C (18.0 F) | n/a | n/a |
| Nov | 23.9 C (75.0 F) | -21.7 C (-7.1 F) | n/a | n/a |
| Dec | 16.3 C (61.3 F) | -34.4 C (-29.9 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1938 | 8 |
| 1939 | 33 |
| 1940 | 55 |
| 1941 | 33 |
| 1942 | 43 |
| 1943 | 42 |
| 1944 | 34 |
| 1945 | 50 |
| 1946 | 52 |
| 1947 | 43 |
| 1948 | 39 |
| 1949 | 44 |
| 1950 | 38 |
| 1951 | 38 |
| 1952 | 18 |
| 1953 | 36 |
| 1954 | 27 |
| 1955 | 34 |
| 1956 | 39 |
| 1957 | 38 |
| 1958 | 23 |
| 1959 | 36 |
| 1960 | 15 |
| 1961 | 25 |
| 1962 | 27 |
| 1963 | 33 |
| 1964 | 29 |
| 1965 | 41 |
| 1966 | 25 |
| 1967 | 25 |
| 1968 | 26 |
| 1969 | 15 |
| 1970 | 26 |
| 1971 | 19 |
| 1972 | 20 |
| 1973 | 23 |
| 1974 | 18 |
| 1975 | 24 |
| 1976 | 35 |
| 1977 | 26 |
| 1978 | 25 |
| 1979 | 56 |
| 1980 | 28 |
| 1981 | 37 |
| 1982 | 31 |
| 1983 | 32 |
All-Time Record Progression
1 new records| Date | Kind | Detail |
|---|---|---|
| 1981-01-03 | Record low maximum temperature | Record low maximum temperature -28.1 C (-18.6 F) |
Wettest Day of Each Month
Sep: 80.0 mm (3.1 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 33.5 mm (1.3 in) | 22 January 1957 |
| Feb | 39.6 mm (1.6 in) | 16 February 1954 |
| Mar | 44.2 mm (1.7 in) | 21 March 1980 |
| Apr | 42.4 mm (1.7 in) | 15 April 1956 |
| May | 42.9 mm (1.7 in) | 25 May 1943 |
| Jun | 58.2 mm (2.3 in) | 17 June 1946 |
| Jul | 69.6 mm (2.7 in) | 9 July 1967 |
| Aug | 66.7 mm (2.6 in) | 5 August 1981 |
| Sep | 80.0 mm (3.1 in) | 9 September 1942 |
| Oct | 59.4 mm (2.3 in) | 12 October 1946 |
| Nov | 42.4 mm (1.7 in) | 26 November 1979 |
| Dec | 43.7 mm (1.7 in) | 9 December 1973 |
Period of Record Coverage
1938 to 1983| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1938 | 61 | 17% | No |
| 1939 | 362 | 99% | Yes |
| 1940 | 366 | 100% | Yes |
| 1941 | 365 | 100% | Yes |
| 1942 | 365 | 100% | Yes |
| 1943 | 365 | 100% | Yes |
| 1944 | 366 | 100% | Yes |
| 1945 | 365 | 100% | Yes |
| 1946 | 365 | 100% | Yes |
| 1947 | 365 | 100% | Yes |
| 1948 | 366 | 100% | Yes |
| 1949 | 365 | 100% | Yes |
| 1950 | 365 | 100% | Yes |
| 1951 | 365 | 100% | Yes |
| 1952 | 366 | 100% | Yes |
| 1953 | 365 | 100% | Yes |
| 1954 | 365 | 100% | Yes |
| 1955 | 365 | 100% | Yes |
| 1956 | 366 | 100% | Yes |
| 1957 | 365 | 100% | Yes |
| 1958 | 365 | 100% | Yes |
| 1959 | 365 | 100% | Yes |
| 1960 | 366 | 100% | Yes |
| 1961 | 365 | 100% | Yes |
| 1962 | 365 | 100% | Yes |
| 1963 | 365 | 100% | Yes |
| 1964 | 366 | 100% | Yes |
| 1965 | 365 | 100% | Yes |
| 1966 | 365 | 100% | Yes |
| 1967 | 365 | 100% | Yes |
| 1968 | 366 | 100% | Yes |
| 1969 | 365 | 100% | Yes |
| 1970 | 365 | 100% | Yes |
| 1971 | 365 | 100% | Yes |
| 1972 | 366 | 100% | Yes |
| 1973 | 364 | 100% | Yes |
| 1974 | 365 | 100% | Yes |
| 1975 | 365 | 100% | Yes |
| 1976 | 366 | 100% | Yes |
| 1977 | 365 | 100% | Yes |
| 1978 | 365 | 100% | Yes |
| 1979 | 365 | 100% | Yes |
| 1980 | 366 | 100% | Yes |
| 1981 | 365 | 100% | Yes |
| 1982 | 365 | 100% | Yes |
| 1983 | 365 | 100% | Yes |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 22 December 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily rain | 14.8 mm (0.6 in) | 4.6 mm (0.18 in) | 33 years | 20 of 100 (Routine) |
| 22 December 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily snowfall | 12.2 cm (4.8 in) | 3.3 cm (1.3 in) | 12 years | 14 of 100 (Routine) |
| 15 December 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily high min | -0.1 C (31.8 F) | 1.3 C (2.3 F) | 1 year | 5 of 100 (Routine) |
| 14 December 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily high min | 0.0 C (32.0 F) | 2.2 C (4.0 F) | 29 years | 14 of 100 (Routine) |
| 12 December 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily rain | 29.4 mm (1.2 in) | 12.1 mm (0.5 in) | 10 years | 27 of 100 (Routine) |
| 6 December 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily rain | 29.9 mm (1.2 in) | 14.0 mm (0.6 in) | 5 years | 28 of 100 (Routine) |
| 6 December 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily snowfall | 24.8 cm (9.8 in) | 6.8 cm (2.7 in) | 5 years | 19 of 100 (Routine) |
| 16 November 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily snowfall | 17.4 cm (6.9 in) | 8.3 cm (3.3 in) | 16 years | 30 of 100 (Routine) |
| 13 November 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily low min | -9.3 C (15.3 F) | 0.4 C (0.7 F) | 41 years | 16 of 100 (Routine) |
| 13 November 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily low max | -1.8 C (28.8 F) | 0.1 C (0.2 F) | 12 years | 7 of 100 (Routine) |
| 11 November 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily rain | 18.2 mm (0.7 in) | 4.0 mm (0.16 in) | 36 years | 20 of 100 (Routine) |
| 11 November 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily snowfall | 5.2 cm (2.0 in) | 3.4 cm (1.3 in) | 9 years | 14 of 100 (Routine) |
| 4 November 1983 | Ottawa Macdonald-Cartier Int'l, CA | monthly snowfall | 25.6 cm (10.1 in) | 0.2 cm (0.1 in) | 38 years | 25 of 100 (Routine) |
| 29 October 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily snowfall | 0.4 cm (0.2 in) | 0.4 cm (0.2 in) | 44 years | 18 of 100 (Routine) |
| 13 October 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily high max | 24.8 C (76.6 F) | 1.5 C (2.7 F) | 40 years | 18 of 100 (Routine) |
| 8 October 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily rain | 24.6 mm (1.0 in) | 2.5 mm (0.10 in) | 17 years | 12 of 100 (Routine) |
| 5 October 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily rain | 40.2 mm (1.6 in) | 3.1 mm (0.12 in) | 9 years | 10 of 100 (Routine) |
| 4 October 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily rain | 21.2 mm (0.8 in) | 0.1 mm (0.00 in) | 41 years | 16 of 100 (Routine) |
| 3 October 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily high min | 14.2 C (57.6 F) | 1.4 C (2.5 F) | 9 years | 9 of 100 (Routine) |
| 20 September 1983 | Ottawa Macdonald-Cartier Int'l, CA | daily high max | 31.0 C (87.8 F) | 1.6 C (2.9 F) | 36 years | 18 of 100 (Routine) |
Climate Trend
45 complete years, 1939 to 1983| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1939 | 4.8 C | -0.91 C |
| 1940 | 4.5 C | -1.22 C |
| 1941 | 5.8 C | +0.10 C |
| 1942 | 6.2 C | +0.46 C |
| 1943 | 4.6 C | -1.09 C |
| 1944 | 6.0 C | +0.32 C |
| 1945 | 5.8 C | +0.04 C |
| 1946 | 6.0 C | +0.28 C |
| 1947 | 5.5 C | -0.21 C |
| 1948 | 6.1 C | +0.36 C |
| 1949 | 6.7 C | +0.95 C |
| 1950 | 5.1 C | -0.58 C |
| 1951 | 5.8 C | +0.11 C |
| 1952 | 6.7 C | +0.94 C |
| 1953 | 7.6 C | +1.85 C |
| 1954 | 5.4 C | -0.30 C |
| 1955 | 6.2 C | +0.52 C |
| 1956 | 5.2 C | -0.47 C |
| 1957 | 6.5 C | +0.79 C |
| 1958 | 5.4 C | -0.34 C |
| 1959 | 6.1 C | +0.38 C |
| 1960 | 6.4 C | +0.68 C |
| 1961 | 6.1 C | +0.36 C |
| 1962 | 5.2 C | -0.54 C |
| 1963 | 5.1 C | -0.66 C |
| 1964 | 6.1 C | +0.35 C |
| 1965 | 5.2 C | -0.50 C |
| 1966 | 5.7 C | -0.01 C |
| 1967 | 5.1 C | -0.63 C |
| 1968 | 5.3 C | -0.38 C |
| 1969 | 5.7 C | +0.02 C |
| 1970 | 5.2 C | -0.55 C |
| 1971 | 5.3 C | -0.40 C |
| 1972 | 4.8 C | -0.96 C |
| 1973 | 6.8 C | +1.06 C |
| 1974 | 5.4 C | -0.31 C |
| 1975 | 6.5 C | +0.74 C |
| 1976 | 4.9 C | -0.83 C |
| 1977 | 5.9 C | +0.16 C |
| 1978 | 5.0 C | -0.68 C |
| 1979 | 5.9 C | +0.21 C |
| 1980 | 5.1 C | -0.60 C |
| 1981 | 6.4 C | +0.64 C |
| 1982 | 5.6 C | -0.08 C |
| 1983 | 6.5 C | +0.80 C |
The fitted trend in annual mean temperature here over 1939 to 1983 is 0.00 C (-0.15 to 0.16) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: 0.00 F (-0.28 to 0.28) per decade. The slope is a straight line fitted to 45 complete years; the brackets give its 95 percent interval.
| Measure | Per decade (C) | Per decade (F) | Period | Complete years | Reading |
|---|---|---|---|---|---|
| Annual mean temperature | 0.00 C (-0.15 to 0.16) per decade | 0.00 F (-0.28 to 0.28) per decade | 1939 to 1983 | 45 | Not clearly different from zero |
| Mean daily maximum | -0.1 C (-0.2 to 0.1) per decade | -0.2 F (-0.4 to 0.1) per decade | 1939 to 1983 | 45 | Not clearly different from zero |
| Mean daily minimum | 0.1 C (-0.1 to 0.3) per decade | 0.2 F (-0.1 to 0.5) per decade | 1939 to 1983 | 45 | 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
1938 to 1983| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 37.8 C (100.0 F) | 1944 | 33.5 C (92.3 F) | 46 |
| Coldest night (TNn) | -36.1 C (-33.0 F) | 1943 | -29.4 C (-20.9 F) | 46 |
| Wettest day (Rx1day) | 80.0 mm (3.1 in) | 1942 | 40.3 mm (1.6 in) | 46 |
| Wettest five days (Rx5day) | 119.3 mm (4.7 in) | 1972 | 66.1 mm (2.6 in) | 46 |
| Longest dry spell (CDD) | 39 days | 1961 | 15 days | 46 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1938 | 23.9 C (75.0 F) |
| 1939 | 34.4 C (93.9 F) |
| 1940 | 32.2 C (90.0 F) |
| 1941 | 36.1 C (97.0 F) |
| 1942 | 36.1 C (97.0 F) |
| 1943 | 33.3 C (91.9 F) |
| 1944 | 37.8 C (100.0 F) |
| 1945 | 32.2 C (90.0 F) |
| 1946 | 35.0 C (95.0 F) |
| 1947 | 35.6 C (96.1 F) |
| 1948 | 35.0 C (95.0 F) |
| 1949 | 36.1 C (97.0 F) |
| 1950 | 32.2 C (90.0 F) |
| 1951 | 31.1 C (88.0 F) |
| 1952 | 32.8 C (91.0 F) |
| 1953 | 36.1 C (97.0 F) |
| 1954 | 31.7 C (89.1 F) |
| 1955 | 36.7 C (98.1 F) |
| 1956 | 34.4 C (93.9 F) |
| 1957 | 32.8 C (91.0 F) |
| 1958 | 31.1 C (88.0 F) |
| 1959 | 35.0 C (95.0 F) |
| 1960 | 31.7 C (89.1 F) |
| 1961 | 31.7 C (89.1 F) |
| 1962 | 34.4 C (93.9 F) |
| 1963 | 36.7 C (98.1 F) |
| 1964 | 35.6 C (96.1 F) |
| 1965 | 33.3 C (91.9 F) |
| 1966 | 36.1 C (97.0 F) |
| 1967 | 31.1 C (88.0 F) |
| 1968 | 33.9 C (93.0 F) |
| 1969 | 33.3 C (91.9 F) |
| 1970 | 32.2 C (90.0 F) |
| 1971 | 33.9 C (93.0 F) |
| 1972 | 31.1 C (88.0 F) |
| 1973 | 34.4 C (93.9 F) |
| 1974 | 32.2 C (90.0 F) |
| 1975 | 35.6 C (96.1 F) |
| 1976 | 32.8 C (91.0 F) |
| 1977 | 33.6 C (92.5 F) |
| 1978 | 33.4 C (92.1 F) |
| 1979 | 32.8 C (91.0 F) |
| 1980 | 32.4 C (90.3 F) |
| 1981 | 34.1 C (93.4 F) |
| 1982 | 34.2 C (93.6 F) |
| 1983 | 33.3 C (91.9 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1938 | -23.9 C (-11.0 F) |
| 1939 | -30.6 C (-23.1 F) |
| 1940 | -28.9 C (-20.0 F) |
| 1941 | -28.9 C (-20.0 F) |
| 1942 | -34.4 C (-29.9 F) |
| 1943 | -36.1 C (-33.0 F) |
| 1944 | -29.4 C (-20.9 F) |
| 1945 | -32.2 C (-26.0 F) |
| 1946 | -30.6 C (-23.1 F) |
| 1947 | -29.4 C (-20.9 F) |
| 1948 | -33.3 C (-27.9 F) |
| 1949 | -23.9 C (-11.0 F) |
| 1950 | -31.1 C (-24.0 F) |
| 1951 | -33.3 C (-27.9 F) |
| 1952 | -31.1 C (-24.0 F) |
| 1953 | -23.3 C (-9.9 F) |
| 1954 | -29.4 C (-20.9 F) |
| 1955 | -30.6 C (-23.1 F) |
| 1956 | -25.0 C (-13.0 F) |
| 1957 | -35.6 C (-32.1 F) |
| 1958 | -30.0 C (-22.0 F) |
| 1959 | -29.4 C (-20.9 F) |
| 1960 | -27.8 C (-18.0 F) |
| 1961 | -28.3 C (-18.9 F) |
| 1962 | -32.2 C (-26.0 F) |
| 1963 | -28.3 C (-18.9 F) |
| 1964 | -25.6 C (-14.1 F) |
| 1965 | -29.4 C (-20.9 F) |
| 1966 | -27.2 C (-17.0 F) |
| 1967 | -31.7 C (-25.1 F) |
| 1968 | -32.8 C (-27.0 F) |
| 1969 | -24.4 C (-11.9 F) |
| 1970 | -28.9 C (-20.0 F) |
| 1971 | -32.2 C (-26.0 F) |
| 1972 | -30.0 C (-22.0 F) |
| 1973 | -28.9 C (-20.0 F) |
| 1974 | -27.2 C (-17.0 F) |
| 1975 | -29.4 C (-20.9 F) |
| 1976 | -31.7 C (-25.1 F) |
| 1977 | -27.9 C (-18.2 F) |
| 1978 | -24.3 C (-11.7 F) |
| 1979 | -29.3 C (-20.7 F) |
| 1980 | -31.6 C (-24.9 F) |
| 1981 | -35.2 C (-31.4 F) |
| 1982 | -30.7 C (-23.3 F) |
| 1983 | -27.8 C (-18.0 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1938 | 11.4 mm (0.4 in) |
| 1939 | 58.7 mm (2.3 in) |
| 1940 | 33.3 mm (1.3 in) |
| 1941 | 36.3 mm (1.4 in) |
| 1942 | 80.0 mm (3.1 in) |
| 1943 | 49.3 mm (1.9 in) |
| 1944 | 33.8 mm (1.3 in) |
| 1945 | 62.0 mm (2.4 in) |
| 1946 | 59.4 mm (2.3 in) |
| 1947 | 41.9 mm (1.6 in) |
| 1948 | 35.3 mm (1.4 in) |
| 1949 | 31.8 mm (1.3 in) |
| 1950 | 34.8 mm (1.4 in) |
| 1951 | 31.2 mm (1.2 in) |
| 1952 | 66.3 mm (2.6 in) |
| 1953 | 32.8 mm (1.3 in) |
| 1954 | 41.4 mm (1.6 in) |
| 1955 | 54.9 mm (2.2 in) |
| 1956 | 42.4 mm (1.7 in) |
| 1957 | 33.5 mm (1.3 in) |
| 1958 | 36.6 mm (1.4 in) |
| 1959 | 58.9 mm (2.3 in) |
| 1960 | 28.2 mm (1.1 in) |
| 1961 | 29.0 mm (1.1 in) |
| 1962 | 51.8 mm (2.0 in) |
| 1963 | 63.0 mm (2.5 in) |
| 1964 | 34.3 mm (1.4 in) |
| 1965 | 26.9 mm (1.1 in) |
| 1966 | 34.5 mm (1.4 in) |
| 1967 | 69.6 mm (2.7 in) |
| 1968 | 44.7 mm (1.8 in) |
| 1969 | 41.1 mm (1.6 in) |
| 1970 | 43.4 mm (1.7 in) |
| 1971 | 37.3 mm (1.5 in) |
| 1972 | 53.1 mm (2.1 in) |
| 1973 | 43.7 mm (1.7 in) |
| 1974 | 34.8 mm (1.4 in) |
| 1975 | 38.4 mm (1.5 in) |
| 1976 | 32.8 mm (1.3 in) |
| 1977 | 39.6 mm (1.6 in) |
| 1978 | 38.5 mm (1.5 in) |
| 1979 | 63.0 mm (2.5 in) |
| 1980 | 44.2 mm (1.7 in) |
| 1981 | 66.7 mm (2.6 in) |
| 1982 | 40.3 mm (1.6 in) |
| 1983 | 40.2 mm (1.6 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1938 | 21.6 mm (0.9 in) |
| 1939 | 105.5 mm (4.2 in) |
| 1940 | 57.2 mm (2.3 in) |
| 1941 | 74.1 mm (2.9 in) |
| 1942 | 87.2 mm (3.4 in) |
| 1943 | 77.8 mm (3.1 in) |
| 1944 | 50.0 mm (2.0 in) |
| 1945 | 80.0 mm (3.1 in) |
| 1946 | 62.2 mm (2.4 in) |
| 1947 | 80.3 mm (3.2 in) |
| 1948 | 60.2 mm (2.4 in) |
| 1949 | 58.5 mm (2.3 in) |
| 1950 | 77.0 mm (3.0 in) |
| 1951 | 46.8 mm (1.8 in) |
| 1952 | 66.3 mm (2.6 in) |
| 1953 | 66.8 mm (2.6 in) |
| 1954 | 63.2 mm (2.5 in) |
| 1955 | 75.3 mm (3.0 in) |
| 1956 | 60.9 mm (2.4 in) |
| 1957 | 53.9 mm (2.1 in) |
| 1958 | 55.9 mm (2.2 in) |
| 1959 | 70.6 mm (2.8 in) |
| 1960 | 50.1 mm (2.0 in) |
| 1961 | 54.4 mm (2.1 in) |
| 1962 | 68.6 mm (2.7 in) |
| 1963 | 76.2 mm (3.0 in) |
| 1964 | 41.7 mm (1.6 in) |
| 1965 | 53.2 mm (2.1 in) |
| 1966 | 54.9 mm (2.2 in) |
| 1967 | 73.9 mm (2.9 in) |
| 1968 | 54.1 mm (2.1 in) |
| 1969 | 96.6 mm (3.8 in) |
| 1970 | 78.0 mm (3.1 in) |
| 1971 | 65.8 mm (2.6 in) |
| 1972 | 119.3 mm (4.7 in) |
| 1973 | 69.1 mm (2.7 in) |
| 1974 | 58.2 mm (2.3 in) |
| 1975 | 77.8 mm (3.1 in) |
| 1976 | 57.9 mm (2.3 in) |
| 1977 | 61.8 mm (2.4 in) |
| 1978 | 56.8 mm (2.2 in) |
| 1979 | 70.0 mm (2.8 in) |
| 1980 | 70.0 mm (2.8 in) |
| 1981 | 116.7 mm (4.6 in) |
| 1982 | 58.7 mm (2.3 in) |
| 1983 | 91.4 mm (3.6 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1938 | 9 days |
| 1939 | 21 days |
| 1940 | 13 days |
| 1941 | 25 days |
| 1942 | 15 days |
| 1943 | 15 days |
| 1944 | 21 days |
| 1945 | 16 days |
| 1946 | 10 days |
| 1947 | 28 days |
| 1948 | 17 days |
| 1949 | 13 days |
| 1950 | 14 days |
| 1951 | 15 days |
| 1952 | 17 days |
| 1953 | 15 days |
| 1954 | 13 days |
| 1955 | 17 days |
| 1956 | 16 days |
| 1957 | 15 days |
| 1958 | 15 days |
| 1959 | 16 days |
| 1960 | 19 days |
| 1961 | 39 days |
| 1962 | 12 days |
| 1963 | 14 days |
| 1964 | 16 days |
| 1965 | 20 days |
| 1966 | 15 days |
| 1967 | 17 days |
| 1968 | 17 days |
| 1969 | 13 days |
| 1970 | 18 days |
| 1971 | 11 days |
| 1972 | 13 days |
| 1973 | 16 days |
| 1974 | 12 days |
| 1975 | 15 days |
| 1976 | 14 days |
| 1977 | 14 days |
| 1978 | 34 days |
| 1979 | 23 days |
| 1980 | 23 days |
| 1981 | 9 days |
| 1982 | 13 days |
| 1983 | 11 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
45 years with a frostAcross 45 years with a frost, the median last spring frost at Ottawa Macdonald-Cartier Int'l falls on 8 May and the median first autumn frost on 1 October, which leaves a median of 145 days between them.
Fitted over all years, the growing season changes by +4.6 days per decade at this station.
| Measure | Median, all years | Earliest period | Recent period (1954 to 1983) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 8 May | n/a | 7 May | n/a | -2.2 days per decade |
| First autumn frost | 1 October | n/a | 2 October | n/a | +2.4 days per decade |
| Growing days | 145 days | n/a | 146 days | n/a | +4.6 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
45 years, 1939 to 1983A day with at least 41.3 mm (1.6 in) of rain is expected about once in 2 years. A day with at least 93.1 mm (3.7 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 41.3 mm (1.6 in) | |
| 5 years | 52.9 mm (2.1 in) | |
| 10 years | 61.3 mm (2.4 in) | |
| 25 years | 73.2 mm (2.9 in) | |
| 50 years | 82.8 mm (3.3 in) | Longer than the 45 years of record |
| 100 years | 93.1 mm (3.7 in) | Longer than the 45 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, 45 years of values from 1939 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: 80.0 mm (3.1 in) in 1942; 69.6 mm (2.7 in) in 1967; 66.7 mm (2.6 in) in 1981.
Station Changes
1 suspectedOne change was suspected in the annual mean temperature of Ottawa Macdonald-Cartier Int'l, at 1964. Each is measured against neighbouring stations.
- Relative to 5 neighbouring stations, the station's annual mean temperature from 1964 ran 0.2 C (0.3 F) lower than in the years before (likely change).
| Year | Shift (C) | Shift (F) | Strength | Neighbours |
|---|---|---|---|---|
| 1964 | -0.2 | -0.3 | likely | 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
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 2026-10-12 (12 October 2026). Records are computed by this site and are not official.
Data as of . Last revised (2026-10-12).