from https://www.dwd.de/EN/ourservices/zeitreihen/zeitreihen.html?nn=24778#buehneTop
May annual temperature in Germany
1881	11.8
1882	12.0
1883	12.4
1884	12.7
1885	10.0
1886	12.7
1887	10.0
1888	12.1
1889	15.8
1890	13.6
1891	12.7
1892	12.2
1893	12.3
1894	11.3
1895	12.2
1896	10.7
1897	10.6
1898	11.3
1899	11.1
1900	10.8
1901	12.8
1902	8.6
1903	12.6
1904	12.3
1905	12.1
1906	13.1
1907	12.9
1908	13.2
1909	10.9
1910	12.3
1911	13.1
1912	11.9
1913	12.4
1914	10.9
1915	13.1
1916	13.1
1917	15.0
1918	14.0
1919	11.6
1920	13.8
1921	14.0
1922	13.6
1923	11.4
1924	13.7
1925	13.9
1926	10.7
1927	10.9
1928	10.1
1929	13.1
1930	11.6
1931	15.1
1932	12.5
1933	11.5
1934	13.3
1935	10.5
1936	12.3
1937	14.7
1938	10.7
1939	10.5
1940	12.2
1941	9.2
1942	12.1
1943	12.8
1944	11.6
1945	14.0
1946	13.9
1947	14.7
1948	13.6
1949	12.2
1950	13.8
1951	11.5
1952	12.3
1953	13.2
1954	12.2
1955	10.3
1956	12.5
1957	9.7
1958	13.3
1959	12.7
1960	12.8
1961	10.3
1962	9.8
1963	12.0
1964	13.6
1965	11.2
1966	13.0
1967	12.5
1968	10.9
1969	12.9
1970	11.4
1971	14.0
1972	11.3
1973	12.5
1974	11.0
1975	11.8
1976	12.8
1977	11.7
1978	11.6
1979	12.4
1980	10.7
1981	13.2
1982	12.4
1983	11.3
1984	10.8
1985	13.4
1986	14.1
1987	9.7
1988	14.2
1989	13.8
1990	13.9
1991	9.5
1992	14.5
1993	14.6
1994	12.6
1995	12.2
1996	11.2
1997	12.7
1998	14.0
1999	13.8
2000	14.6
2001	14.4
2002	13.8
2003	14.1
2004	11.6
2005	12.8
2006	13.1
2007	14.2
2008	14.5
2009	13.6
2010	10.4
2011	13.9
2012	14.2
2013	11.8
2014	12.4
2015	12.3
2016	13.7
2017	14.1
2018	16.0
2019	11.0
2020	11.9
2021	10.7