Olean Weather Records (USC00306196)

Record envelope, standing records and threshold days for Olean (USC00306196), New York, United States, with 118 years of record.

Key Facts for Olean

Olean (USC00306196) is a weather station in New York, United States at 42.07 latitude and -78.45 longitude, 433 m (1,420 ft) above sea level.
The station reports from 1909 to 2026, 118 years of record.
1,464 records set at Olean still stand.
Records are tracked for prcp, snow, snwd: an element needs 30 years of data to be eligible.
Olean set a daily record precipitation of 48.3 mm (1.9 in) on 28 July 2026.

About the Station

Location: New York, United States, 42.07 latitude, -78.45 longitude.
Elevation: 433 m (1,420 ft).
Period of record: 1909 to 2026, 118 years.
Eligible elements: prcp, snow, snwd.

Daily Record Envelope and 2026

44 days at or beyond a record

The band shows the record high and record low for each calendar day at Olean. The lines show the 2026 daily maximum and minimum. 44 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.

Daily record high and record low at Olean, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	18.9 C (66.0 F)	-30.0 C (-22.0 F)	12.8 C (55.0 F)	-23.9 C (-11.0 F)
Feb	22.8 C (73.0 F)	-29.4 C (-20.9 F)	10.6 C (51.1 F)	-27.2 C (-17.0 F)
Mar	26.7 C (80.1 F)	-26.7 C (-16.1 F)	23.3 C (73.9 F)	-12.8 C (9.0 F)
Apr	30.0 C (86.0 F)	-9.4 C (15.1 F)	27.2 C (81.0 F)	-8.9 C (16.0 F)
May	31.7 C (89.1 F)	-5.0 C (23.0 F)	31.7 C (89.1 F)	-1.7 C (28.9 F)
Jun	33.3 C (91.9 F)	-1.1 C (30.0 F)	30.6 C (87.1 F)	3.9 C (39.0 F)
Jul	37.2 C (99.0 F)	6.7 C (44.1 F)	33.9 C (93.0 F)	6.7 C (44.1 F)
Aug	32.2 C (90.0 F)	5.0 C (41.0 F)	28.9 C (84.0 F)	7.8 C (46.0 F)
Sep	32.8 C (91.0 F)	-1.1 C (30.0 F)	30.0 C (86.0 F)	2.8 C (37.0 F)
Oct	30.0 C (86.0 F)	-8.3 C (17.1 F)	25.0 C (77.0 F)	0.6 C (33.1 F)
Nov	25.6 C (78.1 F)	-18.9 C (-2.0 F)	n/a	n/a
Dec	19.4 C (66.9 F)	-24.4 C (-11.9 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Olean still stand. 2018 holds the most, with 119.

All-Time Record Progression

3 new records

3 all-time records were set at Olean between 25 December 1978 and 27 December 1978. Each dot is a new record.

When Olean set new all-time records
Date	Kind	Detail
1978-12-25	Record daily snowfall	Record daily snowfall 58.4 cm (23.0 in)
1978-12-26	Record snow depth	Record snow depth 66.0 cm (26.0 in)
1978-12-27	Record snow depth	Record snow depth 71.1 cm (28.0 in)

Wettest Day of Each Month

Jul: 152.4 mm (6.0 in)

The wettest day on record for each calendar month at Olean. The most was 152.4 mm (6.0 in) on 18 July 1942.

Record daily precipitation for each month at Olean
Month	Record daily precipitation (mm)	Date
Jan	44.7 mm (1.8 in)	8 January 1998
Feb	48.3 mm (1.9 in)	22 February 1937
Mar	57.2 mm (2.3 in)	18 March 1936
Apr	67.1 mm (2.6 in)	6 April 1929
May	70.6 mm (2.8 in)	9 May 2004
Jun	112.0 mm (4.4 in)	20 June 2024
Jul	152.4 mm (6.0 in)	18 July 1942
Aug	92.7 mm (3.6 in)	14 August 1994
Sep	126.5 mm (5.0 in)	29 September 1967
Oct	62.7 mm (2.5 in)	7 October 1959
Nov	66.3 mm (2.6 in)	12 November 2022
Dec	79.8 mm (3.1 in)	1 December 2010

Period of Record Coverage

1927 to 2026

20 years of record at Olean, 1927 to 2026. 5 years have data for under 90 percent of days and are left out of rankings: 1927, 1967, 1969, 1980, 2026.

Days with data per year at Olean
Year	Days with data	Share of year	Complete
1927	24	7%	No
1967	30	8%	No
1969	9	2%	No
1980	31	8%	No
2011	365	100%	Yes
2012	366	100%	Yes
2013	365	100%	Yes
2014	365	100%	Yes
2015	365	100%	Yes
2016	366	100%	Yes
2017	363	99%	Yes
2018	365	100%	Yes
2019	365	100%	Yes
2020	366	100%	Yes
2021	365	100%	Yes
2022	365	100%	Yes
2023	365	100%	Yes
2024	366	100%	Yes
2025	365	100%	Yes
2026	281	77%	No

Latest Records

Latest records at Olean
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
28 July 2026	Olean, US	daily rain	48.3 mm (1.9 in)	2.3 mm (0.09 in)	71 years	33 of 100 (Routine)
26 January 2026	Olean, US	daily snowfall	18.3 cm (7.2 in)	12.5 cm (4.9 in)	47 years	54 of 100 (Notable)
29 November 2025	Olean, US	daily snow depth	20.3 cm (8.0 in)	5.1 cm (2.0 in)	66 years	38 of 100 (Notable)
28 November 2025	Olean, US	daily snowfall	17.8 cm (7.0 in)	1.3 cm (0.5 in)	7 years	14 of 100 (Routine)
28 November 2025	Olean, US	daily snow depth (Tie)	17.8 cm (7.0 in)	tie	66 years	7 of 100 (Routine)
11 November 2025	Olean, US	daily snowfall	10.2 cm (4.0 in)	2.6 cm (1.0 in)	82 years	39 of 100 (Notable)
11 November 2025	Olean, US	daily snow depth	10.2 cm (4.0 in)	2.6 cm (1.0 in)	68 years	34 of 100 (Routine)
20 October 2025	Olean, US	daily rain	39.1 mm (1.5 in)	13.4 mm (0.5 in)	19 years	31 of 100 (Routine)
6 December 2024	Olean, US	daily snow depth (Tie)	22.9 cm (9.0 in)	tie	47 years	6 of 100 (Routine)
4 December 2024	Olean, US	daily snow depth (Tie)	20.3 cm (8.0 in)	tie	17 years	3 of 100 (Routine)
3 December 2024	Olean, US	daily snowfall	27.9 cm (11.0 in)	12.7 cm (5.0 in)	19 years	43 of 100 (Notable)
3 December 2024	Olean, US	daily snow depth	33.0 cm (13.0 in)	12.7 cm (5.0 in)	19 years	31 of 100 (Routine)
7 September 2024	Olean, US	daily rain	50.8 mm (2.0 in)	22.1 mm (0.9 in)	73 years	51 of 100 (Notable)
20 June 2024	Olean, US	monthly rain	112.0 mm (4.4 in)	38.6 mm (1.5 in)	51 years	71 of 100 (Major)
12 April 2024	Olean, US	daily rain	40.9 mm (1.6 in)	14.7 mm (0.6 in)	84 years	55 of 100 (Notable)
3 April 2024	Olean, US	daily rain	28.4 mm (1.1 in)	7.6 mm (0.30 in)	112 years	50 of 100 (Notable)
29 February 2024	Olean, US	daily rain	13.2 mm (0.5 in)	1.8 mm (0.07 in)	40 years	20 of 100 (Routine)
29 January 2024	Olean, US	daily rain	15.7 mm (0.6 in)	2.0 mm (0.08 in)	14 years	17 of 100 (Routine)
22 November 2023	Olean, US	daily rain	17.8 mm (0.7 in)	1.8 mm (0.07 in)	66 years	20 of 100 (Routine)
11 September 2023	Olean, US	daily rain	22.1 mm (0.9 in)	7.4 mm (0.29 in)	29 years	20 of 100 (Routine)

Climate Trend

15 complete years, 2011 to 2025

One stripe for each of 15 complete years at Olean, 2011 to 2025. Blue stripes are years cooler than the station's own mean of 8.6 C (47.4 F); red stripes are warmer. The coolest year was 2014, at 7.1 C (44.7 F), and the warmest was 2012, at 9.7 C (49.4 F). The strongest colour marks a difference of 1.6 C (2.9 F).

Annual mean temperature at Olean as warming stripes, 2011 to 2025
Year	Annual mean temperature	Difference from the station mean
2011	8.8 C	+0.27 C
2012	9.7 C	+1.13 C
2013	8.0 C	-0.54 C
2014	7.1 C	-1.50 C
2015	8.0 C	-0.58 C
2016	9.2 C	+0.60 C
2017	9.0 C	+0.46 C
2018	8.1 C	-0.47 C
2019	7.9 C	-0.66 C
2020	8.9 C	+0.34 C
2021	9.1 C	+0.53 C
2022	7.8 C	-0.73 C
2023	9.2 C	+0.61 C
2024	9.6 C	+1.00 C
2025	8.1 C	-0.42 C

This station does not have enough complete years (30 are needed) to fit a temperature trend.

A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.

Extremes by Year

1909 to 2026

Yearly extremes at Olean: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	37.2 C (99.0 F)	2011	32.2 C (90.0 F)	20
Coldest night (TNn)	-30.0 C (-22.0 F)	2022	-24.1 C (-11.5 F)	20
Wettest day (Rx1day)	152.4 mm (6.0 in)	1942	49.2 mm (1.9 in)	114
Wettest five days (Rx5day)	209.8 mm (8.3 in)	1972	76.5 mm (3.0 in)	114
Longest dry spell (CDD)	24 days	1957	14 days	114

Hottest day (TXx)

The hottest day of the year at Olean, 1909 to 2026. The record is 37.2 C (99.0 F) in 2011, marked on the chart; the median year is 32.2 C (90.0 F).

Hottest day (TXx) at Olean by year
Year	Hottest day (TXx)
1909	n/a
1910	n/a
1911	n/a
1912	n/a
1913	n/a
1914	n/a
1915	n/a
1916	n/a
1917	n/a
1918	n/a
1919	n/a
1920	n/a
1925	n/a
1926	n/a
1927	12.8 C (55.0 F)
1928	n/a
1929	n/a
1930	n/a
1931	n/a
1932	n/a
1933	n/a
1934	n/a
1935	n/a
1936	n/a
1937	n/a
1938	n/a
1939	n/a
1940	n/a
1941	n/a
1942	n/a
1943	n/a
1944	n/a
1945	n/a
1946	n/a
1947	n/a
1948	n/a
1949	n/a
1950	n/a
1951	n/a
1952	n/a
1953	n/a
1954	n/a
1955	n/a
1956	n/a
1957	n/a
1958	n/a
1959	n/a
1960	n/a
1961	n/a
1962	n/a
1963	n/a
1964	n/a
1965	n/a
1966	n/a
1967	31.1 C (88.0 F)
1968	n/a
1969	28.3 C (82.9 F)
1970	n/a
1971	n/a
1972	n/a
1973	n/a
1974	n/a
1975	n/a
1976	n/a
1977	n/a
1978	n/a
1979	n/a
1980	28.9 C (84.0 F)
1981	n/a
1982	n/a
1983	n/a
1984	n/a
1985	n/a
1986	n/a
1987	n/a
1988	n/a
1989	n/a
1990	n/a
1991	n/a
1992	n/a
1993	n/a
1994	n/a
1995	n/a
1996	n/a
1997	n/a
1998	n/a
1999	n/a
2000	n/a
2001	n/a
2002	n/a
2003	n/a
2004	n/a
2005	n/a
2006	n/a
2007	n/a
2008	n/a
2009	n/a
2010	n/a
2011	37.2 C (99.0 F)
2012	33.9 C (93.0 F)
2013	32.2 C (90.0 F)
2014	31.1 C (88.0 F)
2015	31.7 C (89.1 F)
2016	32.2 C (90.0 F)
2017	31.7 C (89.1 F)
2018	33.9 C (93.0 F)
2019	31.7 C (89.1 F)
2020	32.8 C (91.0 F)
2021	32.8 C (91.0 F)
2022	32.8 C (91.0 F)
2023	31.1 C (88.0 F)
2024	32.2 C (90.0 F)
2025	33.3 C (91.9 F)
2026	33.9 C (93.0 F)

Coldest night (TNn)

The coldest night of the year at Olean, 1909 to 2026. The record is -30.0 C (-22.0 F) in 2022, marked on the chart; the median year is -24.1 C (-11.5 F).

Coldest night (TNn) at Olean by year
Year	Coldest night (TNn)
1909	n/a
1910	n/a
1911	n/a
1912	n/a
1913	n/a
1914	n/a
1915	n/a
1916	n/a
1917	n/a
1918	n/a
1919	n/a
1920	n/a
1925	n/a
1926	n/a
1927	-14.4 C (6.1 F)
1928	n/a
1929	n/a
1930	n/a
1931	n/a
1932	n/a
1933	n/a
1934	n/a
1935	n/a
1936	n/a
1937	n/a
1938	n/a
1939	n/a
1940	n/a
1941	n/a
1942	n/a
1943	n/a
1944	n/a
1945	n/a
1946	n/a
1947	n/a
1948	n/a
1949	n/a
1950	n/a
1951	n/a
1952	n/a
1953	n/a
1954	n/a
1955	n/a
1956	n/a
1957	n/a
1958	n/a
1959	n/a
1960	n/a
1961	n/a
1962	n/a
1963	n/a
1964	n/a
1965	n/a
1966	n/a
1967	-1.1 C (30.0 F)
1968	n/a
1969	12.2 C (54.0 F)
1970	n/a
1971	n/a
1972	n/a
1973	n/a
1974	n/a
1975	n/a
1976	n/a
1977	n/a
1978	n/a
1979	n/a
1980	-1.7 C (28.9 F)
1981	n/a
1982	n/a
1983	n/a
1984	n/a
1985	n/a
1986	n/a
1987	n/a
1988	n/a
1989	n/a
1990	n/a
1991	n/a
1992	n/a
1993	n/a
1994	n/a
1995	n/a
1996	n/a
1997	n/a
1998	n/a
1999	n/a
2000	n/a
2001	n/a
2002	n/a
2003	n/a
2004	n/a
2005	n/a
2006	n/a
2007	n/a
2008	n/a
2009	n/a
2010	n/a
2011	-27.2 C (-17.0 F)
2012	-22.2 C (-8.0 F)
2013	-21.1 C (-6.0 F)
2014	-26.1 C (-15.0 F)
2015	-29.4 C (-20.9 F)
2016	-23.9 C (-11.0 F)
2017	-24.4 C (-11.9 F)
2018	-27.8 C (-18.0 F)
2019	-29.4 C (-20.9 F)
2020	-26.1 C (-15.0 F)
2021	-20.6 C (-5.1 F)
2022	-30.0 C (-22.0 F)
2023	-23.3 C (-9.9 F)
2024	-17.8 C (0.0 F)
2025	-24.4 C (-11.9 F)
2026	-27.2 C (-17.0 F)

Wettest day (Rx1day)

The wettest day of the year at Olean, 1909 to 2026. The record is 152.4 mm (6.0 in) in 1942, marked on the chart; the median year is 49.2 mm (1.9 in).

Wettest day (Rx1day) at Olean by year
Year	Wettest day (Rx1day)
1909	44.2 mm (1.7 in)
1910	48.3 mm (1.9 in)
1911	41.1 mm (1.6 in)
1912	48.8 mm (1.9 in)
1913	35.6 mm (1.4 in)
1914	36.1 mm (1.4 in)
1915	43.2 mm (1.7 in)
1916	70.1 mm (2.8 in)
1917	41.9 mm (1.6 in)
1918	56.9 mm (2.2 in)
1919	49.5 mm (1.9 in)
1920	19.1 mm (0.8 in)
1925	44.2 mm (1.7 in)
1926	72.4 mm (2.9 in)
1927	60.5 mm (2.4 in)
1928	38.1 mm (1.5 in)
1929	67.1 mm (2.6 in)
1930	31.5 mm (1.2 in)
1931	38.1 mm (1.5 in)
1932	44.5 mm (1.8 in)
1933	47.0 mm (1.9 in)
1934	37.8 mm (1.5 in)
1935	49.0 mm (1.9 in)
1936	57.2 mm (2.3 in)
1937	62.2 mm (2.4 in)
1938	34.5 mm (1.4 in)
1939	61.0 mm (2.4 in)
1940	44.5 mm (1.8 in)
1941	41.7 mm (1.6 in)
1942	152.4 mm (6.0 in)
1943	57.2 mm (2.3 in)
1944	39.9 mm (1.6 in)
1945	54.9 mm (2.2 in)
1946	64.5 mm (2.5 in)
1947	53.1 mm (2.1 in)
1948	40.4 mm (1.6 in)
1949	50.8 mm (2.0 in)
1950	54.9 mm (2.2 in)
1951	40.4 mm (1.6 in)
1952	34.8 mm (1.4 in)
1953	46.0 mm (1.8 in)
1954	50.8 mm (2.0 in)
1955	47.5 mm (1.9 in)
1956	40.6 mm (1.6 in)
1957	53.8 mm (2.1 in)
1958	44.5 mm (1.8 in)
1959	62.7 mm (2.5 in)
1960	39.6 mm (1.6 in)
1961	47.0 mm (1.9 in)
1962	54.9 mm (2.2 in)
1963	44.7 mm (1.8 in)
1964	27.9 mm (1.1 in)
1965	37.3 mm (1.5 in)
1966	72.9 mm (2.9 in)
1967	126.5 mm (5.0 in)
1968	38.1 mm (1.5 in)
1969	34.8 mm (1.4 in)
1970	35.3 mm (1.4 in)
1971	24.1 mm (0.9 in)
1972	73.4 mm (2.9 in)
1973	47.5 mm (1.9 in)
1974	32.8 mm (1.3 in)
1975	80.5 mm (3.2 in)
1976	54.6 mm (2.1 in)
1977	66.3 mm (2.6 in)
1978	53.6 mm (2.1 in)
1979	43.4 mm (1.7 in)
1980	61.2 mm (2.4 in)
1981	60.5 mm (2.4 in)
1982	52.8 mm (2.1 in)
1983	43.7 mm (1.7 in)
1984	61.0 mm (2.4 in)
1985	31.2 mm (1.2 in)
1986	49.8 mm (2.0 in)
1987	35.1 mm (1.4 in)
1988	36.8 mm (1.4 in)
1989	45.5 mm (1.8 in)
1990	56.6 mm (2.2 in)
1991	50.3 mm (2.0 in)
1992	54.6 mm (2.1 in)
1993	63.8 mm (2.5 in)
1994	92.7 mm (3.6 in)
1995	50.8 mm (2.0 in)
1996	50.5 mm (2.0 in)
1997	34.3 mm (1.4 in)
1998	50.8 mm (2.0 in)
1999	56.1 mm (2.2 in)
2000	50.0 mm (2.0 in)
2001	45.7 mm (1.8 in)
2002	61.5 mm (2.4 in)
2003	81.5 mm (3.2 in)
2004	84.6 mm (3.3 in)
2005	68.6 mm (2.7 in)
2006	36.3 mm (1.4 in)
2007	39.4 mm (1.6 in)
2008	54.9 mm (2.2 in)
2009	42.2 mm (1.7 in)
2010	79.8 mm (3.1 in)
2011	56.1 mm (2.2 in)
2012	42.9 mm (1.7 in)
2013	47.0 mm (1.9 in)
2014	61.0 mm (2.4 in)
2015	56.4 mm (2.2 in)
2016	62.5 mm (2.5 in)
2017	35.3 mm (1.4 in)
2018	46.5 mm (1.8 in)
2019	54.6 mm (2.1 in)
2020	49.3 mm (1.9 in)
2021	50.8 mm (2.0 in)
2022	66.3 mm (2.6 in)
2023	44.2 mm (1.7 in)
2024	112.0 mm (4.4 in)
2025	39.1 mm (1.5 in)
2026	48.3 mm (1.9 in)

Wettest five days (Rx5day)

The wettest five days of the year at Olean, 1909 to 2026. The record is 209.8 mm (8.3 in) in 1972, marked on the chart; the median year is 76.5 mm (3.0 in).

Wettest five days (Rx5day) at Olean by year
Year	Wettest five days (Rx5day)
1909	44.2 mm (1.7 in)
1910	71.7 mm (2.8 in)
1911	82.5 mm (3.2 in)
1912	69.4 mm (2.7 in)
1913	103.4 mm (4.1 in)
1914	93.0 mm (3.7 in)
1915	81.9 mm (3.2 in)
1916	61.8 mm (2.4 in)
1917	72.2 mm (2.8 in)
1918	61.8 mm (2.4 in)
1919	85.7 mm (3.4 in)
1920	27.7 mm (1.1 in)
1925	60.5 mm (2.4 in)
1926	94.0 mm (3.7 in)
1927	116.1 mm (4.6 in)
1928	76.7 mm (3.0 in)
1929	89.5 mm (3.5 in)
1930	64.0 mm (2.5 in)
1931	60.2 mm (2.4 in)
1932	52.7 mm (2.1 in)
1933	86.1 mm (3.4 in)
1934	49.5 mm (1.9 in)
1935	96.2 mm (3.8 in)
1936	101.9 mm (4.0 in)
1937	119.3 mm (4.7 in)
1938	67.9 mm (2.7 in)
1939	75.7 mm (3.0 in)
1940	61.3 mm (2.4 in)
1941	78.3 mm (3.1 in)
1942	199.9 mm (7.9 in)
1943	83.3 mm (3.3 in)
1944	64.5 mm (2.5 in)
1945	73.4 mm (2.9 in)
1946	110.3 mm (4.3 in)
1947	67.8 mm (2.7 in)
1948	76.3 mm (3.0 in)
1949	85.3 mm (3.4 in)
1950	71.6 mm (2.8 in)
1951	47.3 mm (1.9 in)
1952	79.0 mm (3.1 in)
1953	68.0 mm (2.7 in)
1954	70.1 mm (2.8 in)
1955	107.0 mm (4.2 in)
1956	84.6 mm (3.3 in)
1957	67.3 mm (2.6 in)
1958	78.5 mm (3.1 in)
1959	75.9 mm (3.0 in)
1960	91.9 mm (3.6 in)
1961	93.0 mm (3.7 in)
1962	78.7 mm (3.1 in)
1963	45.7 mm (1.8 in)
1964	49.6 mm (2.0 in)
1965	43.7 mm (1.7 in)
1966	84.8 mm (3.3 in)
1967	145.8 mm (5.7 in)
1968	55.6 mm (2.2 in)
1969	53.3 mm (2.1 in)
1970	71.2 mm (2.8 in)
1971	47.6 mm (1.9 in)
1972	209.8 mm (8.3 in)
1973	87.7 mm (3.5 in)
1974	57.7 mm (2.3 in)
1975	87.6 mm (3.4 in)
1976	82.6 mm (3.3 in)
1977	116.8 mm (4.6 in)
1978	66.6 mm (2.6 in)
1979	64.4 mm (2.5 in)
1980	104.9 mm (4.1 in)
1981	69.3 mm (2.7 in)
1982	82.2 mm (3.2 in)
1983	74.0 mm (2.9 in)
1984	97.8 mm (3.9 in)
1985	52.7 mm (2.1 in)
1986	77.1 mm (3.0 in)
1987	78.8 mm (3.1 in)
1988	79.1 mm (3.1 in)
1989	73.4 mm (2.9 in)
1990	106.2 mm (4.2 in)
1991	59.4 mm (2.3 in)
1992	76.2 mm (3.0 in)
1993	106.6 mm (4.2 in)
1994	112.7 mm (4.4 in)
1995	63.1 mm (2.5 in)
1996	86.4 mm (3.4 in)
1997	66.8 mm (2.6 in)
1998	108.7 mm (4.3 in)
1999	64.2 mm (2.5 in)
2000	73.7 mm (2.9 in)
2001	59.2 mm (2.3 in)
2002	104.5 mm (4.1 in)
2003	161.7 mm (6.4 in)
2004	96.5 mm (3.8 in)
2005	112.3 mm (4.4 in)
2006	72.6 mm (2.9 in)
2007	56.9 mm (2.2 in)
2008	86.1 mm (3.4 in)
2009	76.3 mm (3.0 in)
2010	95.0 mm (3.7 in)
2011	84.6 mm (3.3 in)
2012	58.2 mm (2.3 in)
2013	60.2 mm (2.4 in)
2014	106.3 mm (4.2 in)
2015	75.2 mm (3.0 in)
2016	115.9 mm (4.6 in)
2017	85.3 mm (3.4 in)
2018	72.9 mm (2.9 in)
2019	81.3 mm (3.2 in)
2020	68.3 mm (2.7 in)
2021	91.9 mm (3.6 in)
2022	72.9 mm (2.9 in)
2023	70.4 mm (2.8 in)
2024	121.5 mm (4.8 in)
2025	74.7 mm (2.9 in)
2026	87.0 mm (3.4 in)

Longest dry spell (CDD)

The longest dry spell of the year at Olean, 1909 to 2026. The record is 24 days in 1957, marked on the chart; the median year is 14 days.

Longest dry spell (CDD) at Olean by year
Year	Longest dry spell (CDD)
1909	14 days
1910	14 days
1911	10 days
1912	11 days
1913	18 days
1914	16 days
1915	11 days
1916	9 days
1917	15 days
1918	13 days
1919	15 days
1920	11 days
1925	5 days
1926	15 days
1927	13 days
1928	16 days
1929	17 days
1930	19 days
1931	13 days
1932	14 days
1933	12 days
1934	15 days
1935	14 days
1936	23 days
1937	10 days
1938	19 days
1939	15 days
1940	16 days
1941	15 days
1942	17 days
1943	19 days
1944	16 days
1945	10 days
1946	16 days
1947	18 days
1948	12 days
1949	18 days
1950	18 days
1951	15 days
1952	17 days
1953	13 days
1954	13 days
1955	13 days
1956	14 days
1957	24 days
1958	12 days
1959	15 days
1960	16 days
1961	10 days
1962	11 days
1963	23 days
1964	23 days
1965	9 days
1966	19 days
1967	11 days
1968	18 days
1969	18 days
1970	16 days
1971	12 days
1972	9 days
1973	15 days
1974	9 days
1975	13 days
1976	10 days
1977	14 days
1978	17 days
1979	17 days
1980	20 days
1981	16 days
1982	14 days
1983	16 days
1984	16 days
1985	15 days
1986	15 days
1987	21 days
1988	17 days
1989	14 days
1990	13 days
1991	10 days
1992	10 days
1993	10 days
1994	10 days
1995	15 days
1996	11 days
1997	15 days
1998	12 days
1999	14 days
2000	16 days
2001	13 days
2002	11 days
2003	13 days
2004	14 days
2005	15 days
2006	17 days
2007	13 days
2008	11 days
2009	12 days
2010	11 days
2011	14 days
2012	11 days
2013	11 days
2014	10 days
2015	12 days
2016	10 days
2017	14 days
2018	13 days
2019	10 days
2020	17 days
2021	16 days
2022	9 days
2023	21 days
2024	15 days
2025	16 days
2026	12 days

Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.

Rainfall Return Levels

109 years, 1910 to 2025

A day with at least 48.7 mm (1.9 in) of rain is expected about once in 2 years. A day with at least 104.1 mm (4.1 in) of rain is expected about once in 100 years.

Rainfall return levels at Olean: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	48.7 mm (1.9 in)
5 years	62.1 mm (2.4 in)
10 years	71.5 mm (2.8 in)
25 years	84.1 mm (3.3 in)
50 years	93.9 mm (3.7 in)
100 years	104.1 mm (4.1 in)

The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 109 years of values from 1910 to 2025.

A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.

The largest wettest-day totals in the fit: 126.5 mm (5.0 in) in 1967; 112.0 mm (4.4 in) in 2024; 92.7 mm (3.6 in) in 1994.

Download the Data

Data for Olean standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Olean threshold days by year: CSV or JSON. Field meanings are on the data page.

Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-13 (13 October 2026). Records are computed by this site and are not official.

Data as of 2026-10-12. Last revised 12 October 2026 (2026-10-12).