Alton Threshold Days by Year (CA006150243)
17 fixed thresholds counted per year at Alton (CA006150243): hot days, frost, tropical nights and heavy rain, with the most days in a year.
Key Facts for Alton Thresholds
- Alton: days with a maximum temperature at or below 0 C (32 F) in 55 years, most in 1895 with 106.
- Alton: days with a maximum temperature at or above 30 C (86 F) in 54 years, most in 1900 with 44.
- Alton: nights with a minimum temperature at or below 0 C (32 F) in 54 years, most in 1907 with 224.
- Alton: nights with a minimum temperature at or below -10 C (14 F) in 54 years, most in 1904 with 110.
- 17 fixed thresholds have at least one qualifying day at Alton.
Days at or above 30 C (86 F)
54 years with a qualifying day| Year | Days | Decade average |
|---|---|---|
| 1887 | 25 | 12.3 |
| 1888 | 7 | 12.3 |
| 1889 | 5 | 12.3 |
| 1890 | 5 | 11.3 |
| 1891 | 4 | 11.3 |
| 1892 | 7 | 11.3 |
| 1893 | 8 | 11.3 |
| 1894 | 15 | 11.3 |
| 1895 | 18 | 11.3 |
| 1896 | 16 | 11.3 |
| 1897 | 10 | 11.3 |
| 1898 | 17 | 11.3 |
| 1899 | 13 | 11.3 |
| 1900 | 44 | 15 |
| 1901 | 19 | 15 |
| 1902 | 3 | 15 |
| 1903 | 3 | 15 |
| 1904 | 5 | 15 |
| 1905 | 6 | 15 |
| 1906 | 14 | 15 |
| 1907 | 13 | 15 |
| 1908 | 30 | 15 |
| 1909 | 13 | 15 |
| 1910 | 10 | 20.3 |
| 1911 | 30 | 20.3 |
| 1912 | 14 | 20.3 |
| 1913 | 23 | 20.3 |
| 1914 | 18 | 20.3 |
| 1916 | 28 | 20.3 |
| 1917 | 9 | 20.3 |
| 1918 | 20 | 20.3 |
| 1919 | 31 | 20.3 |
| 1920 | 6 | 10.8 |
| 1921 | 21 | 10.8 |
| 1922 | 8 | 10.8 |
| 1923 | 18 | 10.8 |
| 1924 | 4 | 10.8 |
| 1925 | 16 | 10.8 |
| 1926 | 5 | 10.8 |
| 1927 | 6 | 10.8 |
| 1928 | 6 | 10.8 |
| 1929 | 18 | 10.8 |
| 1930 | 18 | 20 |
| 1931 | 23 | 20 |
| 1932 | 9 | 20 |
| 1933 | 26 | 20 |
| 1934 | 24 | 20 |
| 1947 | 1 | 4.5 |
| 1948 | 8 | 4.5 |
| 1951 | 3 | 9.3 |
| 1952 | 13 | 9.3 |
| 1953 | 12 | 9.3 |
| 1962 | 10 | 11 |
| 1963 | 12 | 11 |
| Year | First date | Last date |
|---|---|---|
| 1887 | 1887-05-23 | 1887-09-14 |
| 1888 | 1888-06-18 | 1888-08-04 |
| 1889 | 1889-05-19 | 1889-09-03 |
| 1890 | 1890-07-08 | 1890-08-04 |
| 1891 | 1891-06-16 | 1891-08-08 |
| 1892 | 1892-06-13 | 1892-08-19 |
| 1893 | 1893-06-21 | 1893-08-12 |
| 1894 | 1894-06-17 | 1894-09-03 |
| 1895 | 1895-05-06 | 1895-09-23 |
| 1896 | 1896-06-21 | 1896-09-12 |
| 1897 | 1897-07-04 | 1897-09-11 |
| 1898 | 1898-07-03 | 1898-09-04 |
| 1899 | 1899-07-25 | 1899-09-01 |
| 1900 | 1900-05-14 | 1900-10-07 |
| 1901 | 1901-06-27 | 1901-08-23 |
| 1902 | 1902-05-23 | 1902-07-08 |
| 1903 | 1903-07-02 | 1903-07-10 |
| 1904 | 1904-06-26 | 1904-07-20 |
| 1905 | 1905-06-20 | 1905-08-13 |
| 1906 | 1906-05-17 | 1906-09-19 |
| 1907 | 1907-06-18 | 1907-08-20 |
| 1908 | 1908-05-29 | 1908-09-29 |
| 1909 | 1909-06-22 | 1909-09-15 |
| 1910 | 1910-06-17 | 1910-07-25 |
| 1911 | 1911-05-20 | 1911-08-15 |
| 1912 | 1912-06-29 | 1912-09-11 |
| 1913 | 1913-06-07 | 1913-08-19 |
| 1914 | 1914-06-08 | 1914-09-22 |
| 1916 | 1916-07-12 | 1916-09-07 |
| 1917 | 1917-07-23 | 1917-08-02 |
| 1918 | 1918-07-16 | 1918-08-24 |
| 1919 | 1919-05-30 | 1919-09-09 |
| 1920 | 1920-06-11 | 1920-09-27 |
| 1921 | 1921-05-21 | 1921-09-11 |
| 1922 | 1922-06-24 | 1922-09-09 |
| 1923 | 1923-06-18 | 1923-08-30 |
| 1924 | 1924-07-20 | 1924-09-01 |
| 1925 | 1925-06-01 | 1925-08-31 |
| 1926 | 1926-07-09 | 1926-08-07 |
| 1927 | 1927-06-30 | 1927-09-15 |
| 1928 | 1928-07-02 | 1928-09-11 |
| 1929 | 1929-05-30 | 1929-09-07 |
| 1930 | 1930-06-05 | 1930-09-12 |
| 1931 | 1931-06-14 | 1931-09-21 |
| 1932 | 1932-06-16 | 1932-09-01 |
| 1933 | 1933-06-07 | 1933-09-09 |
| 1934 | 1934-06-01 | 1934-08-20 |
| 1947 | 1947-09-07 | 1947-09-07 |
| 1948 | 1948-07-10 | 1948-08-28 |
| 1951 | 1951-07-31 | 1951-08-31 |
| 1952 | 1952-07-04 | 1952-09-15 |
| 1953 | 1953-06-20 | 1953-09-04 |
| 1962 | 1962-05-15 | 1962-09-13 |
| 1963 | 1963-06-26 | 1963-07-28 |
Every Fixed Threshold
| Threshold | Years with a qualifying day | Most days in a year | Year | Latest year days |
|---|---|---|---|---|
| 30 C (86 F): Days | 54 | 44 | 1900 | 12 |
| 35 C (95 F): Days | 14 | 8 | 1911 | 1 |
| 90 F (32.2 C): Days | 47 | 21 | 1900 | 2 |
| 100 F (37.8 C): Days | 1 | 1 | 1911 | 1 |
| 0 C (32 F): Ice days (max | 55 | 106 | 1895 | 87 |
| 0 C (32 F): Frost days (min | 54 | 224 | 1907 | 144 |
| -10 C (14 F): Days with min | 54 | 110 | 1904 | 70 |
| -20 C (-4 F): Days with min | 53 | 46 | 1904 | 26 |
| -30 C (-22 F): Days with min | 20 | 5 | 1904 | 1 |
| 20 C (68 F): Tropical nights (min | 30 | 10 | 1933 | 1 |
| 10 mm (0.39 in): Days with 10 mm or more rain | 49 | 44 | 1951 | 44 |
| 25 mm (0.98 in): Days with 25 mm or more rain | 49 | 11 | 1912 | 3 |
| 50 mm (1.97 in): Days with 50 mm or more rain | 23 | 2 | 1893 | 1 |
| 100 mm (3.94 in): Days with 100 mm or more rain | 1 | 1 | 1904 | 1 |
| 10 cm (3.9 in): Days with 10 cm or more snowfall | 52 | 13 | 1947 | 10 |
| 25 cm (9.8 in): Days with 25 cm or more snowfall | 10 | 2 | 1907 | 1 |
| 50 cm (19.7 in): Days with 50 cm or more snowfall | 1 | 1 | 1930 | 1 |
Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1887.
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). Threshold counts are computed by this site.
Data as of . Last revised (2026-10-17).