Tri-Cities, WA: September

30 September 2026: September 2026 averaged 63.2°F in Tri-Cities, WA, the coldest September since 2018, tied 39th coldest of 123 (with 1992, 1919 and 1897).

September 2026

Mean temperature: 63.2°F; Coldest since 2018; 39th coldest of 123
Precipitation: 0.33 in; Wettest since 2021; 47th wettest of 119

A normal September in Tri-Cities, WA (1991 to 2020): a mean temperature of 64.9°F, between 62.3°F and 67.3°F in eight years of ten and 0.16 in of precipitation, between 0.00 in and 0.77 in in eight years of ten.

The mean temperature of every September in Tri-Cities, WA since 1894: 63.2°F in 2026; the lowest is 58.6°F, in 1926.

Normal range, 62.3 to 67.3°F

Every year, ranked, as a table

Every September in Tri-Cities, WA from 1894 to 2026, ranked: the mean temperature, the mean high and the mean low from the warmest, the precipitation from the wettest; a year missing more than a tenth of its days is not ranked.

Year	Mean, °F	Rank	High, °F	Rank	Low, °F	Rank	Precipitation, in	Rank	Days missing
2026	63.2	82	77.9	90	48.5	74	0.33	47	0
2025	69.2	4	85	6	53.4	7	0.20	62	0
2024	68.5	7	84.6	9	52.3	16	0.11	80	0
2023	65.8	35	80.1	58	51.4	24	0.20	62	0
2022	67.9	10	84.1	14	51.9	20	0.12	77	2
2021	65.8	35	81.8	37	49.8	51	0.41	37	0
2020	66.8	23	82.9	27	50.7	34	0.05	88	0
2019	66.1	30	79.3	68	53	13	0.55	24	0
2018	62.8	92	79.2	72	46.5	107	trace	107	0
2017	65.2	48	80.8	49	49.6	55	0.13	74	0
2016	63.1	86	78.8	81	47.3	94	0.24	58	0
2015	62.8	92	79.2	72	46.4	110	0.12	77	0
2014	65.4	40	82	35	48.8	71	0.05	88	0
2013	66.9	19	80.6	51	53.3	11	0.99	8	0
2012	64.2	65	82.8	28	45.6	115	trace	107	0
2011	66.2	27	84.4	12	48	80	0.03	94	0
2010	64.6	63	78.6	83	50.6	37	1.07	5	0
2009	65.4	40	83	26	47.8	85	0.15	73	0
2008	62.2	104	80.4	54	44	122	0.09	83	0
2007	62.6	96	79.4	67	45.7	114	0.56	23	0
2006	63.5	75	81.3	42	45.6	115	0.36	41	0
2005	62.3	102	79	75	45.5	118	0.74	14	0
2004	63.5	75	79	75	47.9	82	0.16	70	0
2003	66.2	27	83.1	25	49.2	61	0.24	58	0
2002	62.7	94	80.3	57	45.1	120	0.01	105	0
2001	65.3	45	83.6	17	46.9	100	0.03	94	0
2000	62	110	77.4	96	46.6	104	1.01	7	0
1999	60.9	117	80.9	47	40.8	123	trace	107	0
1998	66.9	19	84.9	7	48.9	69	0.25	56	0
1997	67.6	12	80.1	58	55.1	1	0.34	45	1
1996	63.8	72	77.4	96	50.2	42	0.18	66	0
1995	68.9	5	82.8	28	55	2	0.41	37	0
1994	68.5	7	83.5	18	53.4	7	0.07	86	0
1993	65.2	48	81	45	49.4	58	0.02	99	0
1992	63.2	82	76.4	106	50	47	0.35	43	0
1991	67.3	17	83.2	24	51.5	23	trace	107	1
1990	70.3	2	85.8	3	54.8	3	0.00	116	0
1989	65.9	32	81.1	44	50.7	34	trace	107	0
1988	64.9	56	79.3	68	50.3	41	0.38	39	1
1987	67.8	11	84	15	52	19	0.00	116	1
1986	63.7	73	74.5	117	52.2	17	0.63	18	2
1985	60.3	119	73.9	118	46.8	102	0.52	26	0
1984	63	89	76.5	104	49.1	64	0.52	26	1
1983			77.8	92			0.27	52	6
1982			79	75			1.16	4	9
1981	64.8	58	82	35	47.5	90	0.57	22	0
1980	65.9	32	80.4	54	51.3	27	1.63	2	0
1979	67.5	15	83.3	20	51.7	22	0.25	56	0
1978	62.4	100	74.9	114	49.8	51			1
1977	61.5	115	73.4	123	49.7	54	0.58	21	0
1976			83.4	19			0.02	99	10
1975	64.8	58	82.7	31	46.9	100	0.00	116	0
1974	65.8	35	84.3	13	47.2	95	trace	107	0
1973	64.8	58	80.5	52	49	65	0.63	18	0
1972	62.6	96	77.4	96	47.7	86	0.18	66	0
1971	60.8	118	73.9	118	47.6	87	0.85	11	0
1970	60.2	120	73.8	120	46.5	107	0.13	74	0
1969	65.3	45	77.9	90	52.7	14	0.50	29	0
1968	65.9	32	78.4	85	53.3	11	0.47	32	1
1967	69.7	3	85.3	4	54	6	0.10	81	0
1966	67.6	12	81.7	39	53.4	7	0.08	84	0
1965	62.3	102	76.5	104	48.2	77	0.06	87	0
1964	62.9	91	76.2	107	49.5	57	0.03	94	0
1963	68.7	6	82.8	28	54.6	4	0.20	62	0
1962	65.8	35	80.4	54	51.1	30	0.26	53	0
1961	63.1	86	76.1	108	50.1	46	0.32	50	0
1960	64	69	79.2	72	48.9	69	0.23	61	0
1959	62.1	107	73.5	121	50.7	34	1.49	3	0
1958	64.3	64	77.2	100	51.4	24	0.04	92	0
1957	65.1	52	81	45	49.2	61	0.93	9	0
1956	63.5	75	79.6	64	47.4	92	0.01	105	1
1955	63	89	78	88	48.1	79	0.51	28	1
1954	63.1	86	76.8	103	49.4	58	0.37	40	0
1953	66.3	26	82.6	32	49.8	51	trace	107	1
1952	65.4	40	81.5	40	49	65	0.35	43	1
1951	65.4	40	80.5	52	50.2	42	0.19	65	0
1950	64.2	65	81.3	42	46.6	104	0.03	94	1
1949	64.8	58	79.3	68	50.9	32	0.24	58	1
1948	62.1	107	76.1	108	48.2	77	0.16	70	0
1947	65.1	52	78.7	82	51.4	24	0.87	10	0
1946	62.2	104	74.9	114	49.6	55	0.67	17	0
1945	62.1	107	77.7	95	46.5	107	0.34	45	0
1944	66.9	19	83.8	16	50	47	0.02	99	0
1943	67.5	15	87.4	1	47.5	90	0.00	116	0
1942	67	18	85.3	4	48.7	73	0.45	34	0
1941	61.7	112	74.7	116	49	65	0.73	15	1
1940	68.3	9	83.3	20	53.4	7	0.48	31	1
1939	66.7	24	84.6	9	48.8	71			0
1938	70.8	1	87.1	2	54.5	5	0.13	74	0
1937	64.9	56	78.4	85	51.3	27			0
1936	62.2	104	77.4	96	47	98			0
1935	65.5	39	80.8	49	50.2	42			0
1934	63.7	73	78.3	87	49	65	0.49	30	0
1933	61.8	111	75.1	112	48.5	74	0.30	51	0
1932	63.5	75	78.9	79	48	80			0
1931	65.1	52	78	88	52.1	18	0.04	92	0
1930	65	55	79	75	51.1	30	0.82	12	0
1929	61.5	115	75.4	111	47.6	87			0
1928	63.3	79	78.9	79	47.9	82	0.42	36	1
1927	61.6	113	72.4	124	50.8	33	1.79	1	0
1926	58.6	123	72.3	125	44.6	121	0.62	20	2
1925	63.3	79	77.2	100	49.3	60	1.03	6	0
1924	64.1	68	79.7	63	48.5	74	0.36	41	0
1923	65.4	40	81.5	40	49.2	61	0.46	33	0
1922	66.1	30	82.2	33	50	47	0.02	99	1
1921	59.5	121	73.5	121	45.4	119	0.17	69	1
1920	62.6	96	77.8	92	47.4	92	0.33	47	0
1919	63.2	82	79.3	68	47.1	96	0.33	47	0
1918	66.9	19	83.3	20	51.2	29	0.08	84	1
1917	65.2	48	79.9	62	50.6	37	0.26	53	2
1916	64.7	62	79.5	65	49.9	50	trace	107	0
1915	62.4	100	77.8	92	47	98	0.12	77	0
1914	62.7	94	75.1	112	50.2	42	0.26	53	0
1913	64.2	65	82.1	34	46.1	113	0.02	99	3
1912	63.3	79	80	61	46.7	103	0.02	99	1
1911									14
1910	62.6	96	79.5	65	45.6	115	0.05	88	0
1908	65.2	48	83.3	20	47.1	96	trace	107	1
1907	61.6	113	77	102	46.3	111	0.18	66	2
1906							0.03	94	8
1905	66.7	24	80.9	47	52.4	15	0.16	70	0
1904	65.3	45	84.9	7	46.2	112	0.10	81	2
1899	67.6	12	84.5	11	50.6	37	0.44	35	0
1898	66.2	27	81.8	37	50.5	40	0.05	88	0
1897	63.2	82	78.5	84	47.9	82	0.54	25	0
1896	63.9	70	80.1	58	47.6	87	0.70	16	0
1895	58.7	122	70.9	126	46.6	104	0.78	13	0
1894	63.9	70	75.9	110	51.8	21			0

Warmest, coldest, wettest and driest

Warmest
Year	Mean, °F
1938	70.8
1990	70.3
1967	69.7
2025	69.2
1995	68.9
1963	68.7
2024	68.5
1994	68.5
1940	68.3
2022	67.9

Coldest
Year	Mean, °F
1926	58.6
1895	58.7
1921	59.5
1970	60.2
1985	60.3
1971	60.8
1999	60.9
1977	61.5
1929	61.5
1927	61.6
More years share the last value

Wettest
Year	Precipitation, in
1927	1.79
1980	1.63
1959	1.49
1982	1.16
2010	1.07
1925	1.03
2000	1.01
2013	0.99
1957	0.93
1947	0.87

Driest
Year	Precipitation, in
1990	0.00
1987	0.00
1975	0.00
1943	0.00
2018	trace
2012	trace
1999	trace
1991	trace
1989	trace
1974	trace
More years share the last value

The hottest, coldest and wettest days

Hottest day: 90°F; 10 September 2026
Coldest night: 33°F; 28 September 2026
Wettest day: 0.19 in; 12 September 2026

Every month, season and year

Months

Seasons

Years

Tri-Cities, WA the day's answers

All-time records

Every answer in words

September 2026 brought 0.33 in of precipitation in Tri-Cities, WA, the wettest September since 2021, tied 47th wettest of 119 (with 1920 and 1919).
The hottest day of September 2026 in Tri-Cities, WA: 90°F on Thursday 10 September 2026.
The coldest night of September 2026 in Tri-Cities, WA: a low of 33°F on Monday 28 September 2026.
The wettest day of September 2026 in Tri-Cities, WA: 0.19 in on Saturday 12 September 2026.