Portland Weather Records (USC00176902)
Record envelope, standing records and threshold days for Portland (USC00176902), Maine, United States, with 70 years of record.
Key Facts for Portland
- Portland (USC00176902) is a weather station in Maine, United States at 43.65 latitude and -70.25 longitude, n/a above sea level.
- The station reports from 1871 to 1940, 70 years of record.
- 1,464 records set at Portland still stand.
- Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
- Portland tied a daily record low maximum temperature of 6.1 C (43.0 F) on 22 October 1940.
About the Station
- Location: Maine, United States, 43.65 latitude, -70.25 longitude.
- Elevation: n/a.
- Period of record: 1871 to 1940, 70 years.
- Eligible elements: tmax, tmin, prcp, snow, snwd.
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 | 18.3 C (64.9 F) | -27.8 C (-18.0 F) | n/a | n/a |
| Feb | 14.4 C (57.9 F) | -27.8 C (-18.0 F) | n/a | n/a |
| Mar | 26.1 C (79.0 F) | -20.0 C (-4.0 F) | n/a | n/a |
| Apr | 31.7 C (89.1 F) | -12.8 C (9.0 F) | n/a | n/a |
| May | 35.6 C (96.1 F) | -2.8 C (27.0 F) | n/a | n/a |
| Jun | 35.6 C (96.1 F) | 3.3 C (37.9 F) | n/a | n/a |
| Jul | 39.4 C (102.9 F) | 8.9 C (48.0 F) | n/a | n/a |
| Aug | 36.7 C (98.1 F) | 6.7 C (44.1 F) | n/a | n/a |
| Sep | 35.6 C (96.1 F) | 0.0 C (32.0 F) | n/a | n/a |
| Oct | 29.4 C (84.9 F) | -5.6 C (21.9 F) | n/a | n/a |
| Nov | 23.3 C (73.9 F) | -21.1 C (-6.0 F) | n/a | n/a |
| Dec | 18.3 C (64.9 F) | -29.4 C (-20.9 F) | n/a | n/a |
Which Years Hold Standing Records
1,464 standing records| Year set | Standing records |
|---|---|
| 1874 | 19 |
| 1875 | 27 |
| 1876 | 36 |
| 1877 | 22 |
| 1878 | 29 |
| 1879 | 22 |
| 1880 | 25 |
| 1881 | 33 |
| 1882 | 18 |
| 1883 | 16 |
| 1884 | 17 |
| 1885 | 11 |
| 1886 | 27 |
| 1887 | 30 |
| 1888 | 50 |
| 1889 | 17 |
| 1890 | 23 |
| 1891 | 31 |
| 1892 | 26 |
| 1893 | 16 |
| 1894 | 31 |
| 1895 | 29 |
| 1896 | 29 |
| 1897 | 18 |
| 1898 | 9 |
| 1899 | 22 |
| 1900 | 27 |
| 1901 | 18 |
| 1902 | 19 |
| 1903 | 23 |
| 1904 | 22 |
| 1905 | 18 |
| 1906 | 23 |
| 1907 | 33 |
| 1908 | 21 |
| 1909 | 23 |
| 1910 | 13 |
| 1911 | 23 |
| 1912 | 22 |
| 1913 | 21 |
| 1914 | 46 |
| 1915 | 16 |
| 1916 | 21 |
| 1917 | 30 |
| 1918 | 28 |
| 1919 | 20 |
| 1920 | 20 |
| 1921 | 20 |
| 1922 | 15 |
| 1923 | 27 |
| 1924 | 15 |
| 1925 | 11 |
| 1926 | 7 |
| 1927 | 19 |
| 1928 | 15 |
| 1929 | 21 |
| 1930 | 22 |
| 1931 | 19 |
| 1932 | 20 |
| 1933 | 17 |
| 1934 | 28 |
| 1935 | 12 |
| 1936 | 17 |
| 1937 | 18 |
| 1938 | 26 |
| 1939 | 7 |
| 1940 | 8 |
All-Time Record Progression
10 new records| Date | Kind | Detail |
|---|---|---|
| 1907-01-24 | Record low minimum temperature | Record low minimum temperature -26.7 C (-16.1 F) |
| 1908-07-12 | Record high maximum temperature | Record high maximum temperature 36.7 C (98.1 F) |
| 1911-07-04 | Record high maximum temperature | Record high maximum temperature 39.4 C (102.9 F) |
| 1911-07-04 | Record high minimum temperature | Record high minimum temperature 26.1 C (79.0 F) |
| 1914-02-12 | Record low minimum temperature | Record low minimum temperature -27.2 C (-17.0 F) |
| 1917-12-29 | Record low maximum temperature | Record low maximum temperature -19.4 C (-2.9 F) |
| 1917-12-30 | Record low minimum temperature | Record low minimum temperature -29.4 C (-20.9 F) |
| 1918-02-05 | Record low maximum temperature | Record low maximum temperature -20.0 C (-4.0 F) |
| 1923-01-15 | Record snow depth | Record snow depth 132.1 cm (52.0 in) |
| 1923-01-16 | Record snow depth | Record snow depth 139.7 cm (55.0 in) |
Wettest Day of Each Month
Sep: 134.1 mm (5.3 in)| Month | Record daily precipitation (mm) | Date |
|---|---|---|
| Jan | 75.7 mm (3.0 in) | 15 January 1940 |
| Feb | 77.7 mm (3.1 in) | 22 February 1898 |
| Mar | 83.8 mm (3.3 in) | 16 March 1937 |
| Apr | 83.8 mm (3.3 in) | 1 April 1922 |
| May | 121.4 mm (4.8 in) | 17 May 1916 |
| Jun | 110.5 mm (4.4 in) | 18 June 1922 |
| Jul | 108.0 mm (4.3 in) | 28 July 1939 |
| Aug | 62.5 mm (2.5 in) | 12 August 1892 |
| Sep | 134.1 mm (5.3 in) | 6 September 1896 |
| Oct | 99.8 mm (3.9 in) | 7 October 1873 |
| Nov | 84.6 mm (3.3 in) | 28 November 1889 |
| Dec | 65.5 mm (2.6 in) | 10 December 1878 |
Period of Record Coverage
1874 to 1940| Year | Days with data | Share of year | Complete |
|---|---|---|---|
| 1874 | 275 | 75% | No |
| 1875 | 365 | 100% | Yes |
| 1876 | 366 | 100% | Yes |
| 1877 | 365 | 100% | Yes |
| 1878 | 365 | 100% | Yes |
| 1879 | 365 | 100% | Yes |
| 1880 | 366 | 100% | Yes |
| 1881 | 365 | 100% | Yes |
| 1882 | 365 | 100% | Yes |
| 1883 | 365 | 100% | Yes |
| 1884 | 366 | 100% | Yes |
| 1885 | 365 | 100% | Yes |
| 1886 | 365 | 100% | Yes |
| 1887 | 365 | 100% | Yes |
| 1888 | 366 | 100% | Yes |
| 1889 | 365 | 100% | Yes |
| 1890 | 365 | 100% | Yes |
| 1891 | 365 | 100% | Yes |
| 1892 | 366 | 100% | Yes |
| 1893 | 365 | 100% | Yes |
| 1894 | 365 | 100% | Yes |
| 1895 | 365 | 100% | Yes |
| 1896 | 366 | 100% | Yes |
| 1897 | 365 | 100% | Yes |
| 1898 | 365 | 100% | Yes |
| 1899 | 365 | 100% | Yes |
| 1900 | 365 | 100% | Yes |
| 1901 | 365 | 100% | Yes |
| 1902 | 365 | 100% | Yes |
| 1903 | 365 | 100% | Yes |
| 1904 | 366 | 100% | Yes |
| 1905 | 365 | 100% | Yes |
| 1906 | 365 | 100% | Yes |
| 1907 | 365 | 100% | Yes |
| 1908 | 366 | 100% | Yes |
| 1909 | 365 | 100% | Yes |
| 1910 | 365 | 100% | Yes |
| 1911 | 365 | 100% | Yes |
| 1912 | 366 | 100% | Yes |
| 1913 | 365 | 100% | Yes |
| 1914 | 365 | 100% | Yes |
| 1915 | 365 | 100% | Yes |
| 1916 | 366 | 100% | Yes |
| 1917 | 365 | 100% | Yes |
| 1918 | 365 | 100% | Yes |
| 1919 | 365 | 100% | Yes |
| 1920 | 366 | 100% | Yes |
| 1921 | 365 | 100% | Yes |
| 1922 | 365 | 100% | Yes |
| 1923 | 365 | 100% | Yes |
| 1924 | 366 | 100% | Yes |
| 1925 | 365 | 100% | Yes |
| 1926 | 365 | 100% | Yes |
| 1927 | 365 | 100% | Yes |
| 1928 | 366 | 100% | Yes |
| 1929 | 364 | 100% | Yes |
| 1930 | 365 | 100% | Yes |
| 1931 | 365 | 100% | Yes |
| 1932 | 366 | 100% | Yes |
| 1933 | 365 | 100% | Yes |
| 1934 | 365 | 100% | Yes |
| 1935 | 365 | 100% | Yes |
| 1936 | 366 | 100% | Yes |
| 1937 | 361 | 99% | Yes |
| 1938 | 365 | 100% | Yes |
| 1939 | 365 | 100% | Yes |
| 1940 | 311 | 85% | No |
Latest Records
20| Date | Station | Record | Value | Beat old record by | Old record stood | Significance |
|---|---|---|---|---|---|---|
| 22 October 1940 | Portland, US | daily low max (Tie) | 6.1 C (43.0 F) | tie | 62 years | 6 of 100 (Routine) |
| 19 October 1940 | Portland, US | daily low max | 5.0 C (41.0 F) | 0.6 C (1.1 F) | 33 years | 16 of 100 (Routine) |
| 25 September 1940 | Portland, US | daily rain | 28.4 mm (1.1 in) | 18.5 mm (0.7 in) | 19 years | 26 of 100 (Routine) |
| 7 September 1940 | Portland, US | daily low max (Tie) | 13.9 C (57.0 F) | tie | 51 years | 5 of 100 (Routine) |
| 25 August 1940 | Portland, US | monthly low min | 6.7 C (44.1 F) | 0.5 C (0.9 F) | 30 years | 26 of 100 (Routine) |
| 26 July 1940 | Portland, US | daily high max | 35.0 C (95.0 F) | 0.6 C (1.1 F) | 57 years | 24 of 100 (Routine) |
| 4 July 1940 | Portland, US | daily rain | 29.0 mm (1.1 in) | 0.6 mm (0.02 in) | 56 years | 24 of 100 (Routine) |
| 25 June 1940 | Portland, US | daily low max | 10.6 C (51.1 F) | 2.2 C (4.0 F) | 37 years | 21 of 100 (Routine) |
| 22 June 1940 | Portland, US | daily low min | 7.8 C (46.0 F) | 1.1 C (2.0 F) | 58 years | 26 of 100 (Routine) |
| 21 June 1940 | Portland, US | daily low min (Tie) | 7.2 C (45.0 F) | tie | 22 years | 3 of 100 (Routine) |
| 31 May 1940 | Portland, US | daily rain | 59.4 mm (2.3 in) | 21.0 mm (0.8 in) | 43 years | 39 of 100 (Notable) |
| 22 April 1940 | Portland, US | daily snowfall | 17.8 cm (7.0 in) | 16.3 cm (6.4 in) | 12 years | 34 of 100 (Routine) |
| 22 April 1940 | Portland, US | daily snow depth | 7.6 cm (3.0 in) | 5.1 cm (2.0 in) | 15 years | 14 of 100 (Routine) |
| 22 April 1940 | Portland, US | daily low max | 2.8 C (37.0 F) | 0.5 C (0.9 F) | 12 years | 10 of 100 (Routine) |
| 21 April 1940 | Portland, US | daily low max | 2.2 C (36.0 F) | 1.7 C (3.1 F) | 64 years | 28 of 100 (Routine) |
| 21 April 1940 | Portland, US | daily snowfall | 3.8 cm (1.5 in) | 1.8 cm (0.7 in) | 40 years | 20 of 100 (Routine) |
| 14 April 1940 | Portland, US | daily low min (Tie) | -5.6 C (21.9 F) | tie | 17 years | 2 of 100 (Routine) |
| 23 March 1940 | Portland, US | daily low max | -5.0 C (23.0 F) | 0.6 C (1.1 F) | 43 years | 20 of 100 (Routine) |
| 22 March 1940 | Portland, US | daily snowfall | 16.5 cm (6.5 in) | 0.8 cm (0.3 in) | 35 years | 18 of 100 (Routine) |
| 12 March 1940 | Portland, US | daily low max (Tie) | -3.9 C (25.0 F) | tie | 40 years | 4 of 100 (Routine) |
Climate Trend
65 complete years, 1875 to 1939| Year | Annual mean temperature | Difference from the station mean |
|---|---|---|
| 1875 | 6.8 C | -0.85 C |
| 1876 | 8.1 C | +0.48 C |
| 1877 | 9.3 C | +1.68 C |
| 1878 | 9.7 C | +2.10 C |
| 1879 | 8.5 C | +0.86 C |
| 1880 | 9.2 C | +1.54 C |
| 1881 | 9.0 C | +1.40 C |
| 1882 | 8.9 C | +1.24 C |
| 1883 | 7.9 C | +0.28 C |
| 1884 | 8.7 C | +1.09 C |
| 1885 | 7.5 C | -0.10 C |
| 1886 | 6.9 C | -0.78 C |
| 1887 | 6.8 C | -0.85 C |
| 1888 | 6.0 C | -1.64 C |
| 1889 | 8.1 C | +0.45 C |
| 1890 | 6.8 C | -0.81 C |
| 1891 | 7.7 C | +0.03 C |
| 1892 | 7.3 C | -0.35 C |
| 1893 | 6.3 C | -1.34 C |
| 1894 | 7.5 C | -0.16 C |
| 1895 | 7.3 C | -0.31 C |
| 1896 | 7.0 C | -0.61 C |
| 1897 | 7.3 C | -0.38 C |
| 1898 | 8.0 C | +0.31 C |
| 1899 | 7.6 C | -0.04 C |
| 1900 | 7.9 C | +0.21 C |
| 1901 | 7.3 C | -0.30 C |
| 1902 | 7.4 C | -0.21 C |
| 1903 | 7.2 C | -0.41 C |
| 1904 | 5.6 C | -2.02 C |
| 1905 | 6.7 C | -0.99 C |
| 1906 | 7.2 C | -0.45 C |
| 1907 | 6.3 C | -1.35 C |
| 1908 | 7.8 C | +0.16 C |
| 1909 | 7.5 C | -0.13 C |
| 1910 | 7.7 C | +0.03 C |
| 1911 | 7.5 C | -0.15 C |
| 1912 | 7.2 C | -0.42 C |
| 1913 | 8.3 C | +0.63 C |
| 1914 | 6.7 C | -0.90 C |
| 1915 | 7.9 C | +0.29 C |
| 1916 | 6.9 C | -0.70 C |
| 1917 | 5.9 C | -1.76 C |
| 1918 | 6.8 C | -0.88 C |
| 1919 | 7.7 C | +0.09 C |
| 1920 | 7.4 C | -0.28 C |
| 1921 | 8.4 C | +0.78 C |
| 1922 | 7.7 C | +0.06 C |
| 1923 | 7.2 C | -0.45 C |
| 1924 | 7.3 C | -0.32 C |
| 1925 | 7.7 C | +0.09 C |
| 1926 | 6.6 C | -1.05 C |
| 1927 | 8.1 C | +0.44 C |
| 1928 | 7.9 C | +0.24 C |
| 1929 | 7.8 C | +0.17 C |
| 1930 | 8.5 C | +0.86 C |
| 1931 | 9.3 C | +1.61 C |
| 1932 | 8.9 C | +1.28 C |
| 1933 | 8.1 C | +0.48 C |
| 1934 | 7.5 C | -0.18 C |
| 1935 | 7.7 C | +0.09 C |
| 1936 | 7.9 C | +0.22 C |
| 1937 | 9.0 C | +1.31 C |
| 1938 | 8.6 C | +0.99 C |
| 1939 | 7.5 C | -0.14 C |
The fitted trend in annual mean temperature here over 1875 to 1939 is 0.00 C (-0.12 to 0.11) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.01 F (-0.21 to 0.20) per decade. The slope is a straight line fitted to 65 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 (-0.12 to 0.11) per decade | -0.01 F (-0.21 to 0.20) per decade | 1875 to 1939 | 65 | Not clearly different from zero |
| Mean daily maximum | -0.02 C (-0.13 to 0.10) per decade | -0.03 F (-0.24 to 0.18) per decade | 1875 to 1939 | 65 | Not clearly different from zero |
| Mean daily minimum | 0.01 C (-0.11 to 0.12) per decade | 0.01 F (-0.20 to 0.22) per decade | 1875 to 1939 | 65 | 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
1871 to 1940| Measure | Record | Year of the record | Median year | Years with a value |
|---|---|---|---|---|
| Hottest day (TXx) | 39.4 C (102.9 F) | 1911 | 34.4 C (93.9 F) | 67 |
| Coldest night (TNn) | -29.4 C (-20.9 F) | 1917 | -21.7 C (-7.1 F) | 67 |
| Wettest day (Rx1day) | 134.1 mm (5.3 in) | 1896 | 63.0 mm (2.5 in) | 70 |
| Wettest five days (Rx5day) | 225.8 mm (8.9 in) | 1922 | 92.2 mm (3.6 in) | 70 |
| Longest dry spell (CDD) | 35 days | 1924 | 17 days | 70 |
Hottest day (TXx)
| Year | Hottest day (TXx) |
|---|---|
| 1871 | n/a |
| 1872 | n/a |
| 1873 | n/a |
| 1874 | 33.3 C (91.9 F) |
| 1875 | 32.8 C (91.0 F) |
| 1876 | 36.1 C (97.0 F) |
| 1877 | 32.2 C (90.0 F) |
| 1878 | 35.6 C (96.1 F) |
| 1879 | 33.9 C (93.0 F) |
| 1880 | 34.4 C (93.9 F) |
| 1881 | 34.4 C (93.9 F) |
| 1882 | 34.4 C (93.9 F) |
| 1883 | 31.7 C (89.1 F) |
| 1884 | 31.7 C (89.1 F) |
| 1885 | 32.2 C (90.0 F) |
| 1886 | 34.4 C (93.9 F) |
| 1887 | 35.6 C (96.1 F) |
| 1888 | 35.6 C (96.1 F) |
| 1889 | 33.3 C (91.9 F) |
| 1890 | 33.9 C (93.0 F) |
| 1891 | 35.0 C (95.0 F) |
| 1892 | 35.0 C (95.0 F) |
| 1893 | 33.9 C (93.0 F) |
| 1894 | 36.1 C (97.0 F) |
| 1895 | 33.9 C (93.0 F) |
| 1896 | 33.3 C (91.9 F) |
| 1897 | 34.4 C (93.9 F) |
| 1898 | 36.1 C (97.0 F) |
| 1899 | 33.9 C (93.0 F) |
| 1900 | 34.4 C (93.9 F) |
| 1901 | 35.6 C (96.1 F) |
| 1902 | 32.2 C (90.0 F) |
| 1903 | 32.8 C (91.0 F) |
| 1904 | 33.3 C (91.9 F) |
| 1905 | 32.8 C (91.0 F) |
| 1906 | 33.9 C (93.0 F) |
| 1907 | 35.0 C (95.0 F) |
| 1908 | 36.7 C (98.1 F) |
| 1909 | 34.4 C (93.9 F) |
| 1910 | 32.8 C (91.0 F) |
| 1911 | 39.4 C (102.9 F) |
| 1912 | 33.3 C (91.9 F) |
| 1913 | 38.3 C (100.9 F) |
| 1914 | 33.3 C (91.9 F) |
| 1915 | 31.7 C (89.1 F) |
| 1916 | 34.4 C (93.9 F) |
| 1917 | 33.3 C (91.9 F) |
| 1918 | 34.4 C (93.9 F) |
| 1919 | 36.7 C (98.1 F) |
| 1920 | 33.3 C (91.9 F) |
| 1921 | 33.9 C (93.0 F) |
| 1922 | 34.4 C (93.9 F) |
| 1923 | 35.6 C (96.1 F) |
| 1924 | 32.8 C (91.0 F) |
| 1925 | 35.0 C (95.0 F) |
| 1926 | 37.8 C (100.0 F) |
| 1927 | 32.8 C (91.0 F) |
| 1928 | 35.0 C (95.0 F) |
| 1929 | 35.6 C (96.1 F) |
| 1930 | 33.3 C (91.9 F) |
| 1931 | 36.7 C (98.1 F) |
| 1932 | 31.7 C (89.1 F) |
| 1933 | 33.9 C (93.0 F) |
| 1934 | 35.6 C (96.1 F) |
| 1935 | 35.0 C (95.0 F) |
| 1936 | 35.6 C (96.1 F) |
| 1937 | 36.7 C (98.1 F) |
| 1938 | 33.3 C (91.9 F) |
| 1939 | 35.6 C (96.1 F) |
| 1940 | 35.0 C (95.0 F) |
Coldest night (TNn)
| Year | Coldest night (TNn) |
|---|---|
| 1871 | n/a |
| 1872 | n/a |
| 1873 | n/a |
| 1874 | -18.9 C (-2.0 F) |
| 1875 | -24.4 C (-11.9 F) |
| 1876 | -23.3 C (-9.9 F) |
| 1877 | -21.7 C (-7.1 F) |
| 1878 | -20.6 C (-5.1 F) |
| 1879 | -18.9 C (-2.0 F) |
| 1880 | -19.4 C (-2.9 F) |
| 1881 | -21.1 C (-6.0 F) |
| 1882 | -24.4 C (-11.9 F) |
| 1883 | -22.2 C (-8.0 F) |
| 1884 | -21.1 C (-6.0 F) |
| 1885 | -20.6 C (-5.1 F) |
| 1886 | -24.4 C (-11.9 F) |
| 1887 | -26.1 C (-15.0 F) |
| 1888 | -24.4 C (-11.9 F) |
| 1889 | -22.2 C (-8.0 F) |
| 1890 | -20.0 C (-4.0 F) |
| 1891 | -20.0 C (-4.0 F) |
| 1892 | -20.6 C (-5.1 F) |
| 1893 | -22.8 C (-9.0 F) |
| 1894 | -26.1 C (-15.0 F) |
| 1895 | -23.9 C (-11.0 F) |
| 1896 | -25.0 C (-13.0 F) |
| 1897 | -22.2 C (-8.0 F) |
| 1898 | -21.1 C (-6.0 F) |
| 1899 | -23.3 C (-9.9 F) |
| 1900 | -22.2 C (-8.0 F) |
| 1901 | -23.9 C (-11.0 F) |
| 1902 | -25.6 C (-14.1 F) |
| 1903 | -22.8 C (-9.0 F) |
| 1904 | -23.3 C (-9.9 F) |
| 1905 | -23.3 C (-9.9 F) |
| 1906 | -20.6 C (-5.1 F) |
| 1907 | -26.7 C (-16.1 F) |
| 1908 | -20.6 C (-5.1 F) |
| 1909 | -20.0 C (-4.0 F) |
| 1910 | -20.0 C (-4.0 F) |
| 1911 | -17.8 C (0.0 F) |
| 1912 | -21.7 C (-7.1 F) |
| 1913 | -18.9 C (-2.0 F) |
| 1914 | -27.2 C (-17.0 F) |
| 1915 | -20.6 C (-5.1 F) |
| 1916 | -20.6 C (-5.1 F) |
| 1917 | -29.4 C (-20.9 F) |
| 1918 | -25.6 C (-14.1 F) |
| 1919 | -23.3 C (-9.9 F) |
| 1920 | -26.7 C (-16.1 F) |
| 1921 | -19.4 C (-2.9 F) |
| 1922 | -22.2 C (-8.0 F) |
| 1923 | -22.2 C (-8.0 F) |
| 1924 | -27.8 C (-18.0 F) |
| 1925 | -21.7 C (-7.1 F) |
| 1926 | -17.8 C (0.0 F) |
| 1927 | -21.7 C (-7.1 F) |
| 1928 | -20.6 C (-5.1 F) |
| 1929 | -17.2 C (1.0 F) |
| 1930 | -20.6 C (-5.1 F) |
| 1931 | -17.2 C (1.0 F) |
| 1932 | -17.8 C (0.0 F) |
| 1933 | -27.8 C (-18.0 F) |
| 1934 | -27.8 C (-18.0 F) |
| 1935 | -23.9 C (-11.0 F) |
| 1936 | -18.3 C (-0.9 F) |
| 1937 | -15.0 C (5.0 F) |
| 1938 | -18.3 C (-0.9 F) |
| 1939 | -18.3 C (-0.9 F) |
| 1940 | -18.3 C (-0.9 F) |
Wettest day (Rx1day)
| Year | Wettest day (Rx1day) |
|---|---|
| 1871 | 68.1 mm (2.7 in) |
| 1872 | 53.3 mm (2.1 in) |
| 1873 | 99.8 mm (3.9 in) |
| 1874 | 54.9 mm (2.2 in) |
| 1875 | 63.5 mm (2.5 in) |
| 1876 | 38.1 mm (1.5 in) |
| 1877 | 80.3 mm (3.2 in) |
| 1878 | 65.5 mm (2.6 in) |
| 1879 | 51.1 mm (2.0 in) |
| 1880 | 63.8 mm (2.5 in) |
| 1881 | 61.2 mm (2.4 in) |
| 1882 | 67.6 mm (2.7 in) |
| 1883 | 52.1 mm (2.1 in) |
| 1884 | 65.0 mm (2.6 in) |
| 1885 | 74.9 mm (2.9 in) |
| 1886 | 62.0 mm (2.4 in) |
| 1887 | 55.1 mm (2.2 in) |
| 1888 | 52.1 mm (2.1 in) |
| 1889 | 84.6 mm (3.3 in) |
| 1890 | 58.9 mm (2.3 in) |
| 1891 | 53.3 mm (2.1 in) |
| 1892 | 62.5 mm (2.5 in) |
| 1893 | 67.6 mm (2.7 in) |
| 1894 | 69.6 mm (2.7 in) |
| 1895 | 56.4 mm (2.2 in) |
| 1896 | 134.1 mm (5.3 in) |
| 1897 | 52.3 mm (2.1 in) |
| 1898 | 77.7 mm (3.1 in) |
| 1899 | 53.3 mm (2.1 in) |
| 1900 | 76.5 mm (3.0 in) |
| 1901 | 71.9 mm (2.8 in) |
| 1902 | 55.9 mm (2.2 in) |
| 1903 | 61.0 mm (2.4 in) |
| 1904 | 58.9 mm (2.3 in) |
| 1905 | 59.2 mm (2.3 in) |
| 1906 | 73.2 mm (2.9 in) |
| 1907 | 84.6 mm (3.3 in) |
| 1908 | 35.6 mm (1.4 in) |
| 1909 | 38.1 mm (1.5 in) |
| 1910 | 30.0 mm (1.2 in) |
| 1911 | 70.9 mm (2.8 in) |
| 1912 | 64.5 mm (2.5 in) |
| 1913 | 42.9 mm (1.7 in) |
| 1914 | 57.7 mm (2.3 in) |
| 1915 | 93.0 mm (3.7 in) |
| 1916 | 121.4 mm (4.8 in) |
| 1917 | 105.2 mm (4.1 in) |
| 1918 | 52.6 mm (2.1 in) |
| 1919 | 52.3 mm (2.1 in) |
| 1920 | 71.6 mm (2.8 in) |
| 1921 | 38.9 mm (1.5 in) |
| 1922 | 110.5 mm (4.4 in) |
| 1923 | 44.2 mm (1.7 in) |
| 1924 | 64.0 mm (2.5 in) |
| 1925 | 50.5 mm (2.0 in) |
| 1926 | 68.6 mm (2.7 in) |
| 1927 | 54.9 mm (2.2 in) |
| 1928 | 58.7 mm (2.3 in) |
| 1929 | 66.3 mm (2.6 in) |
| 1930 | 68.6 mm (2.7 in) |
| 1931 | 67.6 mm (2.7 in) |
| 1932 | 100.6 mm (4.0 in) |
| 1933 | 58.9 mm (2.3 in) |
| 1934 | 63.8 mm (2.5 in) |
| 1935 | 57.2 mm (2.3 in) |
| 1936 | 56.9 mm (2.2 in) |
| 1937 | 83.8 mm (3.3 in) |
| 1938 | 49.0 mm (1.9 in) |
| 1939 | 108.0 mm (4.3 in) |
| 1940 | 75.7 mm (3.0 in) |
Wettest five days (Rx5day)
| Year | Wettest five days (Rx5day) |
|---|---|
| 1871 | 141.2 mm (5.6 in) |
| 1872 | 87.6 mm (3.4 in) |
| 1873 | 109.7 mm (4.3 in) |
| 1874 | 71.7 mm (2.8 in) |
| 1875 | 68.6 mm (2.7 in) |
| 1876 | 69.9 mm (2.8 in) |
| 1877 | 131.1 mm (5.2 in) |
| 1878 | 84.6 mm (3.3 in) |
| 1879 | 83.6 mm (3.3 in) |
| 1880 | 78.8 mm (3.1 in) |
| 1881 | 76.2 mm (3.0 in) |
| 1882 | 133.4 mm (5.3 in) |
| 1883 | 79.5 mm (3.1 in) |
| 1884 | 125.8 mm (5.0 in) |
| 1885 | 80.0 mm (3.1 in) |
| 1886 | 151.0 mm (5.9 in) |
| 1887 | 88.9 mm (3.5 in) |
| 1888 | 103.8 mm (4.1 in) |
| 1889 | 86.4 mm (3.4 in) |
| 1890 | 98.0 mm (3.9 in) |
| 1891 | 92.7 mm (3.6 in) |
| 1892 | 106.7 mm (4.2 in) |
| 1893 | 126.8 mm (5.0 in) |
| 1894 | 100.1 mm (3.9 in) |
| 1895 | 84.1 mm (3.3 in) |
| 1896 | 173.7 mm (6.8 in) |
| 1897 | 64.2 mm (2.5 in) |
| 1898 | 115.1 mm (4.5 in) |
| 1899 | 66.2 mm (2.6 in) |
| 1900 | 115.1 mm (4.5 in) |
| 1901 | 108.4 mm (4.3 in) |
| 1902 | 82.0 mm (3.2 in) |
| 1903 | 92.2 mm (3.6 in) |
| 1904 | 99.5 mm (3.9 in) |
| 1905 | 83.8 mm (3.3 in) |
| 1906 | 92.0 mm (3.6 in) |
| 1907 | 102.6 mm (4.0 in) |
| 1908 | 63.9 mm (2.5 in) |
| 1909 | 81.4 mm (3.2 in) |
| 1910 | 60.2 mm (2.4 in) |
| 1911 | 81.6 mm (3.2 in) |
| 1912 | 107.2 mm (4.2 in) |
| 1913 | 60.1 mm (2.4 in) |
| 1914 | 61.2 mm (2.4 in) |
| 1915 | 116.9 mm (4.6 in) |
| 1916 | 125.2 mm (4.9 in) |
| 1917 | 117.4 mm (4.6 in) |
| 1918 | 72.7 mm (2.9 in) |
| 1919 | 63.0 mm (2.5 in) |
| 1920 | 93.2 mm (3.7 in) |
| 1921 | 92.2 mm (3.6 in) |
| 1922 | 225.8 mm (8.9 in) |
| 1923 | 81.3 mm (3.2 in) |
| 1924 | 68.9 mm (2.7 in) |
| 1925 | 107.1 mm (4.2 in) |
| 1926 | 74.0 mm (2.9 in) |
| 1927 | 66.0 mm (2.6 in) |
| 1928 | 98.6 mm (3.9 in) |
| 1929 | 90.6 mm (3.6 in) |
| 1930 | 97.3 mm (3.8 in) |
| 1931 | 94.6 mm (3.7 in) |
| 1932 | 109.2 mm (4.3 in) |
| 1933 | 114.8 mm (4.5 in) |
| 1934 | 99.4 mm (3.9 in) |
| 1935 | 111.6 mm (4.4 in) |
| 1936 | 69.3 mm (2.7 in) |
| 1937 | 99.5 mm (3.9 in) |
| 1938 | 77.9 mm (3.1 in) |
| 1939 | 119.9 mm (4.7 in) |
| 1940 | 88.8 mm (3.5 in) |
Longest dry spell (CDD)
| Year | Longest dry spell (CDD) |
|---|---|
| 1871 | 20 days |
| 1872 | 24 days |
| 1873 | 19 days |
| 1874 | 18 days |
| 1875 | 17 days |
| 1876 | 15 days |
| 1877 | 22 days |
| 1878 | 14 days |
| 1879 | 17 days |
| 1880 | 18 days |
| 1881 | 12 days |
| 1882 | 20 days |
| 1883 | 16 days |
| 1884 | 14 days |
| 1885 | 13 days |
| 1886 | 30 days |
| 1887 | 19 days |
| 1888 | 14 days |
| 1889 | 23 days |
| 1890 | 17 days |
| 1891 | 14 days |
| 1892 | 16 days |
| 1893 | 11 days |
| 1894 | 17 days |
| 1895 | 15 days |
| 1896 | 13 days |
| 1897 | 19 days |
| 1898 | 17 days |
| 1899 | 10 days |
| 1900 | 19 days |
| 1901 | 18 days |
| 1902 | 14 days |
| 1903 | 23 days |
| 1904 | 17 days |
| 1905 | 23 days |
| 1906 | 15 days |
| 1907 | 13 days |
| 1908 | 28 days |
| 1909 | 13 days |
| 1910 | 16 days |
| 1911 | 19 days |
| 1912 | 27 days |
| 1913 | 18 days |
| 1914 | 21 days |
| 1915 | 18 days |
| 1916 | 12 days |
| 1917 | 22 days |
| 1918 | 25 days |
| 1919 | 17 days |
| 1920 | 26 days |
| 1921 | 23 days |
| 1922 | 19 days |
| 1923 | 18 days |
| 1924 | 35 days |
| 1925 | 20 days |
| 1926 | 13 days |
| 1927 | 16 days |
| 1928 | 13 days |
| 1929 | 14 days |
| 1930 | 13 days |
| 1931 | 17 days |
| 1932 | 15 days |
| 1933 | 13 days |
| 1934 | 20 days |
| 1935 | 14 days |
| 1936 | 15 days |
| 1937 | 10 days |
| 1938 | 15 days |
| 1939 | 24 days |
| 1940 | 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
65 years with a frostAcross 65 years with a frost, the median last spring frost at Portland falls on 21 April and the median first autumn frost on 24 October, which leaves a median of 186 days between them.
In 1910 to 1939 the median growing season was 186 days. That is 1 day fewer than in 1875 to 1904.
Fitted over all years, the growing season changes by -0.6 days per decade at this station.
| Measure | Median, all years | Earliest period (1875 to 1904) | Recent period (1910 to 1939) | Recent against earliest | Fitted trend |
|---|---|---|---|---|---|
| Last spring frost | 21 April | 20 April | 24 April | 4 days later | +1.1 days per decade |
| First autumn frost | 24 October | 21 October | 27 October | 6 days later | +0.5 days per decade |
| Growing days | 186 days | 187 days | 186 days | 1 day fewer | -0.6 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
64 years, 1872 to 1940A day with at least 62.2 mm (2.4 in) of rain is expected about once in 2 years. A day with at least 135.9 mm (5.4 in) of rain is expected about once in 100 years.
| Expected about once in | A day with at least | Note |
|---|---|---|
| 2 years | 62.2 mm (2.4 in) | |
| 5 years | 79.5 mm (3.1 in) | |
| 10 years | 91.9 mm (3.6 in) | |
| 25 years | 108.7 mm (4.3 in) | |
| 50 years | 122.0 mm (4.8 in) | |
| 100 years | 135.9 mm (5.4 in) | Longer than the 64 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, 64 years of values from 1872 to 1940.
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: 134.1 mm (5.3 in) in 1896; 121.4 mm (4.8 in) in 1916; 110.5 mm (4.4 in) in 1922.
Station Changes
1 suspectedOne change was suspected in the annual mean temperature of Portland, at 1923. Each is measured against neighbouring stations.
- Relative to 5 neighbouring stations, the station's annual mean temperature from 1923 ran 0.2 C (0.4 F) higher than in the years before (likely change).
| Year | Shift (C) | Shift (F) | Strength | Neighbours |
|---|---|---|---|---|
| 1923 | +0.2 | +0.4 | 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 2026-10-17 (17 October 2026). Records are computed by this site and are not official.
Data as of . Last revised (2025-12-31).