English: w:Warming stripes w:data visualization diagram that represents temperature deviations above (in red stripes) and below (in blue stripes) a 1961-1990 average value. General notes: Credit for general concept of w:warming stripes: climate scientist Ed Hawkins, w:University of Reading, U.K. Data values are visualized using color rather than locations of points on a graph. The average temperature in reference period 1961-1990 determines boundary between blue and red. Horizontal scale is time, from 1850 (left) to 2018 (right). Each hue (up to 8 blue and 8 red) covers a temperature range of 0.1 degrees Celsius. Data is global (not for a locality). Source documentation re the underlying data: https://www.metoffice.gov.uk/hadobs/hadcrut4/index.html https://web.archive.org/web/20190102231319/https://www.metoffice.gov.uk/hadobs/hadcrut4/index.html "HadCRUT4 is a gridded dataset of global historical surface temperature anomalies relative to a 1961-1990 reference period. Data are available for each month since January 1850, on a 5 degree grid. The dataset is a collaborative product of the Met Office Hadley Centre and the Climatic Research Unit at the University of East Anglia. "The gridded data are a blend of the CRUTEM4 land-surface air temperature dataset and the HadSST3 sea-surface temperature (SST) dataset. The dataset is presented as an ensemble of 100 dataset realisations that sample the distribution of uncertainty in the global temperature record given current understanding of non-climatic factors affecting near-surface temperature observations. This ensemble approach allows characterisation of spatially and temporally correlated uncertainty structure in the gridded data, for example arising from uncertainties in methods used to account for changes in SST measurement practices, homogenisation of land station records and the potential impacts of urbanisation. "The HadCRUT4 data are neither interpolated nor variance adjusted." Recommended source citation for the data: Morice, C. P., J. J. Kennedy, N. A. Rayner, and P. D. Jones (2012), Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: The HadCRUT4 dataset, J. Geophys. Res., 117, D08101, doi:10.1029/2011JD017187. From wikitext, with link:  (April 17, 2012). "Quantifying uncertainties in global and regional temperature change using an ensemble of observational estimates: The HadCRUT4 dataset". J. Geophys. Res. 117 (D8). DOI:10.1029/2011JD017187. FAQ re the datasets: https://www.metoffice.gov.uk/hadobs/hadcrut4/faq.html https://web.archive.org/web/20190119092400/https://www.metoffice.gov.uk/hadobs/hadcrut4/faq.html Actual download page: https://www.metoffice.gov.uk/hadobs/hadcrut4/data/current/download.html https://web.archive.org/web/20190619234924/https://www.metoffice.gov.uk/hadobs/hadcrut4/data/current/download.html Creator/Uploader's remarks: I averaged only datasets 1-10 from the 100 HadCRUT4 "Global (NH+SH)/2" datasets, since the standard deviation among each of the 170 year-wise averaged values was small (only 0.01 - 0.02 degrees). That is, the datasets substantially agreed. I averaged the datasets year-wise in Microsoft Excel, and separated the averaged values into categories with "cutoff" (boundary) temperature deviations being multiples of 0.1 degrees (a simple linear relation). I assembled color-coded rectangles in Microsoft Powerpoint, exported, and re-sized using Photoshop. My resulting warming stripes diagram differs from that published by Ed Hawkins because he used different dataset than I did. Mine is based on deviation from a 1961-1990 reference period average, whereas Hawkins' data used a 1971-2000 reference period (separating blue from red). Mine includes data for 2019, whereas Hawkins' June 2019 warming diagram ended with 2018 data. My "cutoff" temperatures (which determine boundaries between adjacent color bands) is probably different, and less sophisticated. I used a different color scheme. I made a typo in the remarks for uploading Version 3: it is 3200x1800 (not 2100x1800). Click at right to show/hide ACTUAL DATA Year-wise averages of data from datasets 1-10 (only): YEAR	Average of Datasets 1-10 (only) 1850	-0.353 1851	-0.199 1852	-0.208 1853	-0.249 1854	-0.230 1855	-0.253 1856	-0.338 1857	-0.443 1858	-0.448 1859	-0.269 1860	-0.331 1861	-0.393 1862	-0.508 1863	-0.268 1864	-0.484 1865	-0.272 1866	-0.237 1867	-0.305 1868	-0.224 1869	-0.247 1870	-0.260 1871	-0.318 1872	-0.213 1873	-0.287 1874	-0.351 1875	-0.381 1876	-0.367 1877	-0.059 1878	0.050 1879	-0.216 1880	-0.213 1881	-0.187 1882	-0.202 1883	-0.283 1884	-0.397 1885	-0.378 1886	-0.359 1887	-0.410 1888	-0.296 1889	-0.162 1890	-0.408 1891	-0.323 1892	-0.448 1893	-0.466 1894	-0.400 1895	-0.383 1896	-0.178 1897	-0.198 1898	-0.405 1899	-0.280 1900	-0.195 1901	-0.251 1902	-0.394 1903	-0.472 1904	-0.513 1905	-0.370 1906	-0.273 1907	-0.459 1908	-0.506 1909	-0.516 1910	-0.485 1911	-0.539 1912	-0.433 1913	-0.421 1914	-0.240 1915	-0.139 1916	-0.379 1917	-0.464 1918	-0.329 1919	-0.270 1920	-0.247 1921	-0.189 1922	-0.299 1923	-0.277 1924	-0.293 1925	-0.217 1926	-0.107 1927	-0.210 1928	-0.205 1929	-0.350 1930	-0.137 1931	-0.085 1932	-0.136 1933	-0.271 1934	-0.128 1935	-0.175 1936	-0.144 1937	-0.024 1938	-0.004 1939	-0.050 1940	0.014 1941	0.026 1942	-0.027 1943	-0.005 1944	0.143 1945	0.024 1946	-0.062 1947	-0.025 1948	-0.026 1949	-0.064 1950	-0.162 1951	-0.040 1952	0.043 1953	0.109 1954	-0.118 1955	-0.182 1956	-0.261 1957	-0.002 1958	0.052 1959	0.021 1960	-0.046 1961	0.044 1962	0.020 1963	0.054 1964	-0.218 1965	-0.137 1966	-0.065 1967	-0.071 1968	-0.110 1969	0.037 1970	-0.022 1971	-0.181 1972	-0.062 1973	0.064 1974	-0.212 1975	-0.148 1976	-0.242 1977	0.047 1978	-0.065 1979	0.054 1980	0.091 1981	0.137 1982	0.006 1983	0.188 1984	-0.019 1985	-0.034 1986	0.042 1987	0.190 1988	0.197 1989	0.115 1990	0.295 1991	0.254 1992	0.105 1993	0.149 1994	0.208 1995	0.322 1996	0.179 1997	0.388 1998	0.536 1999	0.303 2000	0.295 2001	0.441 2002	0.497 2003	0.509 2004	0.450 2005	0.546 2006	0.506 2007	0.493 2008	0.396 2009	0.505 2010	0.560 2011	0.425 2012	0.470 2013	0.514 2014	0.580 2015	0.763 2016	0.796 2017	0.678 2018	0.597 2019	0.762 Data for 2019 not used, beginning with Version 3 of this Wikimedia file.