Temperature Breakdown by Decade

Detroit Area Average Monthly Temperatures from 1960 to 1980
Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Avg for Year
1960	29.0	27.5	26.3	50.6	58.4	66.9	70.8	71.9	66.9	53.2	43.6	25.2	49.2
1961	23.1	30.8	39.1	43.5	55.8	67.9	73.4	72.2	68.8	56.3	41.3	29.0	50.1
1962	22.3	23.5	35.0	49.6	65.2	69.1	71.0	71.0	61.4	54.6	40.3	25.1	49.0
1963	17.2	18.8	37.6	49.4	57.8	70.8	74.5	70.1	63.1	62.7	46.0	23.8	49.3
1964	30.4	28.9	36.1	49.3	63.7	69.6	76.0	69.1	64.4	51.4	44.9	30.4	51.2
1965	25.5	26.6	30.1	44.9	63.1	67.8	70.4	70.0	66.2	51.3	42.7	35.9	49.5
1966	21.4	28.3	38.3	44.4	51.9	68.4	73.5	69.1	62.2	51.0	41.8	28.7	48.3
1967	29.3	23.8	35.9	48.0	51.9	70.4	69.0	67.3	60.4	50.7	35.2	30.9	47.7
1968	20.9	24.3	38.2	50.9	56.1	68.4	71.7	72.5	65.5	53.5	41.0	28.1	49.3
1969	23.1	28.2	33.5	49.4	57.4	64.7	73.2	73.1	64.8	51.4	37.9	26.4	48.6
1970	16.6	24.4	32.9	49.3	60.9	68.4	72.6	72.1	64.5	54.2	40.0	29.0	48.7
1971	20.7	27.4	32.0	45.2	56.4	70.8	69.6	70.3	66.6	58.5	38.5	33.3	49.1
1972	23.8	24.6	32.6	44.6	60.3	64.2	71.2	69.1	63.0	47.3	37.4	29.4	47.3
1973	28.8	25.3	43.3	48.8	55.5	69.9	72.6	72.9	64.9	56.2	41.4	28.7	50.7
1974	26.5	23.6	35.7	49.2	55.2	65.9	72.5	72.3	59.7	48.8	40.6	28.6	48.2
1975	28.3	27.5	32.5	40.9	62.8	69.0	72.2	72.3	59.1	52.9	46.8	29.1	49.5
1976	19.2	33.3	40.4	50.0	56.4	70.6	72.7	70.2	62.1	47.4	33.5	21.5	48.1
1977	12.8	25.2	41.5	52.4	64.4	65.5	75.8	70.6	65.1	47.9	40.5	25.5	48.9
1978	19.6	16.3	30.0	45.5	59.3	66.8	70.6	71.9	67.5	50.2	40.5	28.9	47.3
1979	18.6	16.5	37.7	44.6	56.5	66.6	70.4	67.9	62.6	50.1	39.5	31.9	46.9
1980	24.5	22.2	31.3	45.9	59.8	63.7	72.7	72.7	63.8	46.3	37.4	26.0	47.2