London · United Kingdom

London in September: every year compared

In September, London averages highs of 18.8 °C and lows of 11.4 °C, with 45 mm of precipitation. The warmest September was 2023 (18.1 °C), the coldest 1952 (11.7 °C).

Avg. highAvg. high 18.8 °C

Avg. lowAvg. low 11.4 °C

PrecipitationPrecipitation 45 mm

Rainy daysRainy days 9

Day by day through September

Normal high and low for each day of September in London.

Normal high and low, day by dayNormal 1991–2020

Every September in London, ranked

86 months of September since 1940. The last one, 2025, ranks 38 of 86 (−0.1 °C vs normal).

194019832025

2025 · 14.9 °C · −0.1 °C vs normal · rank 38 of 86

Warmest years

1202318.1 °C
2200617.7 °C
3201617.3 °C
4194917.2 °C
5199916.6 °C

Coldest years

1195211.7 °C
2198612.1 °C
3197212.4 °C
4197412.6 °C
5196512.7 °C

All 86 years in a table

Year	Mean temperature	Daytime highs	Night lows	Precipitation	Hot days (30 °C+)	Rainy days
2025	14.9 °C	18.9 °C	11.3 °C	41 mm	0 days	8 days
2024	15.0 °C	18.7 °C	11.9 °C	116 mm	0 days	18 days
2023	18.1 °C	22.6 °C	14.0 °C	48 mm	1 day	9 days
2022	15.2 °C	18.9 °C	11.7 °C	76 mm	0 days	15 days
2021	16.6 °C	20.7 °C	12.8 °C	49 mm	0 days	8 days
2020	15.3 °C	19.8 °C	11.2 °C	24 mm	0 days	7 days
2019	15.4 °C	19.5 °C	11.4 °C	72 mm	0 days	10 days
2018	14.8 °C	19.3 °C	10.4 °C	27 mm	0 days	7 days
2017	14.3 °C	17.8 °C	10.9 °C	44 mm	0 days	17 days
2016	17.3 °C	21.1 °C	13.6 °C	33 mm	0 days	6 days
2015	13.5 °C	17.2 °C	9.9 °C	58 mm	0 days	10 days
2014	15.9 °C	20.1 °C	12.3 °C	12 mm	0 days	3 days
2013	14.4 °C	18.1 °C	10.9 °C	52 mm	0 days	10 days
2012	14.1 °C	18.4 °C	10.1 °C	43 mm	0 days	5 days
2011	16.0 °C	20.2 °C	12.3 °C	31 mm	0 days	6 days
2010	14.4 °C	18.0 °C	10.8 °C	40 mm	0 days	8 days
2009	15.4 °C	19.2 °C	12.0 °C	14 mm	0 days	3 days
2008	14.0 °C	17.5 °C	11.0 °C	46 mm	0 days	9 days
2007	14.9 °C	18.6 °C	11.3 °C	16 mm	0 days	4 days
2006	17.7 °C	21.6 °C	14.4 °C	48 mm	0 days	8 days
2005	16.1 °C	20.1 °C	12.3 °C	44 mm	0 days	11 days
2004	15.7 °C	19.4 °C	11.8 °C	22 mm	0 days	5 days
2003	15.0 °C	20.2 °C	9.7 °C	14 mm	0 days	3 days
2002	15.0 °C	19.0 °C	11.3 °C	13 mm	0 days	3 days
2001	13.9 °C	16.9 °C	10.8 °C	62 mm	0 days	14 days
2000	15.8 °C	19.1 °C	12.6 °C	80 mm	0 days	11 days
1999	16.6 °C	20.2 °C	13.3 °C	68 mm	0 days	15 days
1998	15.4 °C	18.8 °C	12.7 °C	103 mm	0 days	16 days
1997	15.3 °C	19.4 °C	11.5 °C	9 mm	0 days	3 days
1996	13.9 °C	17.2 °C	10.7 °C	26 mm	0 days	6 days
1995	14.2 °C	17.5 °C	10.8 °C	84 mm	0 days	15 days
1994	13.6 °C	16.5 °C	10.7 °C	68 mm	0 days	11 days
1993	12.9 °C	16.2 °C	9.8 °C	86 mm	0 days	17 days
1992	14.0 °C	17.2 °C	10.6 °C	66 mm	0 days	11 days
1991	15.1 °C	19.4 °C	10.9 °C	51 mm	0 days	9 days
1990	13.6 °C	17.5 °C	9.5 °C	27 mm	0 days	8 days
1989	15.9 °C	19.5 °C	12.4 °C	25 mm	0 days	7 days
1988	14.1 °C	17.5 °C	10.9 °C	39 mm	0 days	9 days
1987	14.7 °C	18.3 °C	11.0 °C	39 mm	0 days	12 days
1986	12.1 °C	16.0 °C	7.9 °C	26 mm	0 days	5 days
1985	15.0 °C	18.9 °C	11.3 °C	18 mm	0 days	6 days
1984	14.1 °C	17.3 °C	10.8 °C	54 mm	0 days	10 days
1983	14.6 °C	17.9 °C	11.5 °C	54 mm	0 days	13 days
1982	15.2 °C	19.4 °C	11.2 °C	55 mm	0 days	11 days
1981	15.2 °C	19.1 °C	11.3 °C	72 mm	0 days	13 days
1980	15.2 °C	18.8 °C	11.8 °C	33 mm	0 days	6 days
1979	14.0 °C	17.8 °C	9.8 °C	15 mm	0 days	4 days
1978	14.5 °C	18.0 °C	10.6 °C	27 mm	0 days	7 days
1977	13.7 °C	16.8 °C	10.2 °C	16 mm	0 days	4 days
1976	14.4 °C	17.7 °C	11.2 °C	77 mm	0 days	11 days
1975	14.4 °C	17.9 °C	10.5 °C	98 mm	0 days	11 days
1974	12.6 °C	15.8 °C	9.3 °C	129 mm	0 days	14 days
1973	15.0 °C	18.8 °C	11.1 °C	53 mm	0 days	9 days
1972	12.4 °C	15.7 °C	9.1 °C	38 mm	0 days	7 days
1971	14.7 °C	19.2 °C	10.4 °C	18 mm	0 days	3 days
1970	15.0 °C	18.9 °C	11.0 °C	41 mm	0 days	9 days
1969	15.0 °C	18.4 °C	11.2 °C	17 mm	0 days	6 days
1968	14.7 °C	17.8 °C	11.6 °C	121 mm	0 days	18 days
1967	14.4 °C	17.6 °C	11.4 °C	66 mm	0 days	14 days
1966	14.5 °C	18.2 °C	10.9 °C	23 mm	0 days	7 days
1965	12.7 °C	16.5 °C	8.9 °C	84 mm	0 days	13 days
1964	15.1 °C	19.5 °C	10.9 °C	10 mm	0 days	3 days
1963	13.3 °C	17.1 °C	9.8 °C	59 mm	0 days	11 days
1962	13.1 °C	17.0 °C	9.4 °C	42 mm	0 days	6 days
1961	16.2 °C	20.3 °C	12.6 °C	35 mm	0 days	8 days
1960	13.8 °C	17.3 °C	10.5 °C	62 mm	0 days	11 days
1959	15.7 °C	20.5 °C	11.2 °C	2 mm	0 days	0 days
1958	15.8 °C	19.2 °C	12.5 °C	77 mm	0 days	10 days
1957	13.4 °C	16.6 °C	10.1 °C	67 mm	0 days	15 days
1956	15.1 °C	18.3 °C	12.1 °C	43 mm	0 days	7 days
1955	14.7 °C	18.8 °C	10.6 °C	32 mm	0 days	6 days
1954	13.5 °C	16.9 °C	10.0 °C	23 mm	0 days	6 days
1953	14.2 °C	18.1 °C	10.3 °C	45 mm	0 days	10 days
1952	11.7 °C	15.3 °C	8.1 °C	67 mm	0 days	12 days
1951	14.8 °C	18.2 °C	11.4 °C	41 mm	0 days	7 days
1950	13.7 °C	16.7 °C	10.6 °C	45 mm	0 days	9 days
1949	17.2 °C	21.2 °C	13.5 °C	51 mm	0 days	8 days
1948	14.7 °C	18.5 °C	10.9 °C	36 mm	0 days	6 days
1947	16.2 °C	20.7 °C	11.7 °C	16 mm	0 days	6 days
1946	14.7 °C	18.3 °C	11.1 °C	55 mm	0 days	11 days
1945	15.1 °C	18.5 °C	11.7 °C	38 mm	0 days	8 days
1944	13.1 °C	16.8 °C	9.5 °C	53 mm	0 days	8 days
1943	14.1 °C	18.1 °C	10.1 °C	20 mm	0 days	5 days
1942	14.4 °C	18.3 °C	11.1 °C	36 mm	0 days	4 days
1941	15.6 °C	19.4 °C	12.0 °C	24 mm	0 days	4 days
1940	14.2 °C	18.5 °C	9.9 °C	23 mm	0 days	7 days

September records

Hottest day

30.6 °C

September 9, 2023 estimate

Coldest night

3.0 °C

September 30, 1988 estimate

Wettest day

41 mm

September 15, 1968 estimate

The weather on your birthday in London

Any day since 1940: high, low, rain, snow, and how warm it was compared with the same date in every other year.

Questions & answers

How warm is London in September?

Highs average 18.8 °C and lows 11.4 °C. A typical September brings 0 hot days (30 °C or more) and 0 frost days.

Does it rain a lot in London in September?

About 45 mm falls in September, over some 9 days with at least 1 mm. The wettest September was 1974 (129 mm), the driest 1959 (2 mm).

What was the warmest September in London?

2023, with a mean temperature of 18.1 °C. The coldest was 1952 (11.7 °C). The last one, 2025, ranks 38 of 86.