Average September Temperature in Key West by Year

This page contains a list of the average monthly high and low temperatures in Key West, Florida for the month of September each year between 1948 and 2023. It is based on NOAA data.

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What Was the Hottest September Ever in Key West?

2018 was the warmest September in the history of Key West, Florida. The average daily high temperature was 90.1 °F, and the average low was 81.5 °F.

What Was the Coldest September Ever in Key West?

1984 was the coolest September in the history of Key West, Florida. The average daily high temperature was 85.0 °F, and the average low was 78.0 °F.

* click column headers to sort

Year	Rank	High (°F)	Low (°F)
2023	3	90.4	80.5
2022	37	88.5	78.3
2021	27	88.2	79.2
2020	2	89.8	81.4
2019	13	89.0	80.0
2018	1	90.1	81.5
2017	12	88.9	80.3
2016	19	88.6	79.1
2015	7	89.1	80.7
2014	26	88.0	79.4
2013	53	87.1	78.5
2012	65	86.6	77.8
2011	8	89.2	80.7
2010	32	88.0	79.1
2009	10	89.8	79.5
2008	63	86.5	78.2
2007	6	90.2	79.7
2006	35	88.4	78.4
2005	41	88.4	78.2
2004	59	87.1	78.0
2003	5	89.6	80.3
2002	18	88.3	79.6
2001	69	86.8	76.8
2000	21	88.9	78.8
1999	40	88.7	78.0
1997	68	87.0	76.8
1996	34	88.6	78.4
1995	17	90.0	78.3
1994	58	87.3	77.9
1993	20	88.9	78.8
1992	47	88.2	78.0
1991	25	89.3	78.2
1990	24	89.5	78.1
1989	4	90.4	79.8
1988	29	88.7	78.4
1987	9	90.7	79.1
1986	36	88.5	78.4
1985	67	86.9	77.4
1984	71	85.0	78.0
1983	57	86.8	78.5
1982	64	87.3	77.2
1981	51	87.4	78.6
1980	14	88.6	80.2
1979	28	88.1	79.2
1978	16	89.1	79.2
1977	39	87.6	79.1
1976	31	88.3	78.8
1975	54	87.8	77.7
1974	15	88.5	80.2
1973	49	87.5	78.7
1972	52	87.9	78.0
1971	55	87.1	78.3
1970	70	86.3	76.9
1969	50	87.0	79.0
1968	45	88.0	78.3
1967	22	88.3	79.4
1966	42	88.0	78.5
1965	43	87.5	79.0
1964	30	88.4	78.7
1963	23	88.9	78.7
1962	46	88.7	77.5
1961	48	87.9	78.2
1960	56	87.7	77.6
1959	60	88.0	77.1
1958	44	88.5	77.9
1957	38	88.5	78.2
1952	62	88.5	76.3
1951	11	90.3	79.0
1950	66	88.2	76.3
1949	33	89.2	77.8
1948	61	88.4	76.5

Weather Station Details

Years	Station	Coordinates
1948–2024	Key West International Airport	location