National Weather Service United States Department of Commerce
Detroit Area Average Monthly Temperatures from 1870 to 1880
Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg for Year
1870                     39.5 26.6  
1871 25.4 26.0 39.8 48.9 60.1 67.3 70.5 71.0 59.0 54.0 33.3 22.9 48.2
1872 23.3 24.1 25.6 47.4 57.7 69.5 74.2 73.4 63.6 49.7 32.6 18.3 46.6
1873 20.4 22.4 30.9 43.1 56.9 70.7 72.2 70.8 61.3 48.1 32.5 32.7 46.8
1874 28.6 27.3 34.3 37.6 58.8 69.1 70.9 69.0 66.4 51.1 37.8 29.7 48.4
1875 15.3 12.3 28.0 40.5 56.7 66.0 69.6 66.8 59.9 46.5 34.5 32.8 44.1
1876 32.1 28.1 29.5 43.7 56.8 68.8 72.8 71.6 59.0 45.8 39.1 17.8 47.1
1877 19.2 33.6 26.0 45.4 56.4 66.1 72.0 71.2 64.3 53.8 39.2 38.1 48.8
1878 27.3 29.2 41.4 53.4 55.4 63.8 74.0 71.2 64.3 51.7 38.9 22.8 49.5
1879 20.8 22.0 34.3 45.2 59.1 65.1 72.8 69.4 58.6 59.6 38.1 28.7 47.8
1880 36.7 32.1 32.8 46.2 63.7 68.4 70.8 69.1 61.8 48.6 29.8 21.8 48.5