Please note, Degree Days and Palmer Indices are not available for Alaska or Hawaii. Palmer Drought Severity Index (PDSI), Palmer Hydrological Drought Index (PHDI), and Palmer Modified Drought Index (PMDI) are not offered for multiple-month time scales. Data are available for bulk download.
Base Period
Trend

Filter
Pennsylvania, Climate Division 4 Palmer Z-Index
December-February
Period
Z-Index
Rank
(out of 130)
December 2024-February 2025-1.604
December 2023-February 20241.21109
December 2022-February 2023-0.3549
December 2021-February 2022-0.8619
December 2020-February 20210.4190
December 2019-February 20200.1571
December 2018-February 20191.65120
December 2017-February 20180.3486
December 2016-February 2017-1.398
December 2015-February 20160.96105
December 2014-February 2015-0.7725
December 2013-February 20140.93103
December 2012-February 20130.1973
December 2011-February 2012-0.4643
December 2010-February 2011-0.4046
December 2009-February 20101.24111
December 2008-February 20090.0664
December 2007-February 20080.5396
December 2006-February 2007-0.6333
December 2005-February 20060.1571
December 2004-February 20050.2983
December 2003-February 20040.4994
December 2002-February 20031.34113
December 2001-February 2002-3.481
December 2000-February 2001-0.6930
December 1999-February 2000-0.2152
December 1998-February 1999-1.0813
December 1997-February 19981.73121
December 1996-February 19970.3084
December 1995-February 19961.22110
December 1994-February 1995-0.1056
December 1993-February 19941.79122
December 1992-February 19930.4591
December 1991-February 1992-0.9517
December 1990-February 19910.4190
December 1989-February 1990-0.7029
December 1988-February 1989-1.1911
December 1987-February 1988-0.6234
December 1986-February 19870.4692
December 1985-February 1986-0.1853
December 1984-February 1985-0.9018
December 1983-February 19842.03125
December 1982-February 1983-1.1412
December 1981-February 19820.0966
December 1980-February 1981-0.5937
December 1979-February 1980-1.853
December 1978-February 19792.86130
December 1977-February 19781.98124
December 1976-February 1977-1.595
December 1975-February 1976-0.0857
December 1974-February 19751.07106
December 1973-February 19740.6898
December 1972-February 19731.37114
December 1971-February 19720.2881
December 1970-February 19711.39115
December 1969-February 19700.4088
December 1968-February 1969-1.457
December 1967-February 1968-0.4942
December 1966-February 1967-0.8520
December 1965-February 1966-0.5539
December 1964-February 1965-0.0460
December 1963-February 19640.77101
December 1962-February 1963-0.6731
December 1961-February 19620.2983
December 1960-February 19610.2074
December 1959-February 19600.2881
December 1958-February 1959-1.0813
December 1957-February 19581.58118
December 1956-February 19570.1772
December 1955-February 1956-0.8321
December 1954-February 1955-0.7227
December 1953-February 1954-1.0415
December 1952-February 19530.74100
December 1951-February 19520.95104
December 1950-February 19511.27112
December 1949-February 1950-0.0362
December 1948-February 19491.47116
December 1947-February 1948-0.6632
December 1946-February 1947-0.2950
December 1945-February 1946-0.5140
December 1944-February 19450.2778
December 1943-February 1944-0.8321
December 1942-February 19430.1168
December 1941-February 1942-0.5041
December 1940-February 1941-0.7526
December 1939-February 1940-0.5738
December 1938-February 19391.14107
December 1937-February 1938-1.319
December 1936-February 19372.13126
December 1935-February 19361.16108
December 1934-February 19350.3285
December 1933-February 1934-1.0316
December 1932-February 1933-0.6135
December 1931-February 1932-1.2410
December 1930-February 1931-2.292
December 1929-February 1930-0.7227
December 1928-February 1929-0.2651
December 1927-February 19280.2275
December 1926-February 1927-0.1155
December 1925-February 19260.5095
December 1924-February 1925-0.3748
December 1923-February 19241.49117
December 1922-February 1923-0.6135
December 1921-February 1922-0.4345
December 1920-February 1921-0.0659
December 1919-February 19200.1168
December 1918-February 19190.3887
December 1917-February 19180.2881
December 1916-February 19170.0865
December 1915-February 19160.2376
December 1914-February 19152.78129
December 1913-February 19140.90102
December 1912-February 19130.0363
December 1911-February 1912-0.1754
December 1910-February 1911-0.8223
December 1909-February 19100.5997
December 1908-February 1909-0.3847
December 1907-February 19081.96123
December 1906-February 19070.7299
December 1905-February 1906-0.0460
December 1904-February 19050.1369
December 1903-February 1904-0.4544
December 1902-February 19032.66128
December 1901-February 19022.51127
December 1900-February 1901-1.586
December 1899-February 19000.4893
December 1898-February 18991.62119
December 1897-February 18980.2577
December 1896-February 1897-0.8223
December 1895-February 1896-0.0857

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