Born in Stryi, Jan Klymko grew up in family of the intelligentsia. His mother Anna née Loudova was a Czech. His older brother Jarosław lived in Prague, where his wife Dr. Ella Folkmannová studied at the Faculty of Medicine at the Charles University in 1925–1931. Her father Dr. Izak Folkmann was the rabbi of the Jewish community in Heřmanův Městec. After graduating from a trade school, Klymko found employment at the “Kunz i Ajaks” company under Eng. Stiks, then worked as a representative of Bata in Lviv. Under German occupation he worked in illegal trade.
In the years 1941–1944 he helped a substantial group of Jews hiding on the “Aryan side” in Lviv, by supplying them with birth certificates, employment certificates and counterfeit Kennkarten of his own making. He also helped them find hiding places. In 1993 Klymko expressed regret that he could not hide anyone in his home: “someone denounced me and the Police showed up at my door. After that, unfortunately, I could not keep anybody at my place. I helped anyway, I helped many different people, whose names now, after over 50 years, I cannot remember very well”. He could travel around Lviv relatively easily because he pretended to be a Czech. After the death of his brother in 1941, he went to Prague to help his sister-in-law Ella Klimko. He managed to save her property from seizure by registering it under his own name. He also provided Ella with financial help that enabled her to survive in the Terezin (Ger. Theresienstadt) ghetto, where she was sent with her father in 1942. In Prague, Klymko was wanted by the Gestapo, but managed to avoid arrest. In February 1942 his father Jan was killed.
The inhabitants of Lviv whom Klymko supplied with forged documents included Maria Hofman, her husband Michał Hofman and Maria's brother Filip Friedman, as well as the pedagogue Ignacy Schneier and his wife Julia née Königsberg from Tovste. After Szneier's escape from the Janowska camp in early June 1943, Klymko supplied him with identity documents issued in the name “Szaniawski”. Szneier worked as a photography lab technician, porter and bookbinder. Klymko also tried to help Julia's blind brother, the lawyer Celek Königsberg, who had been placed in the Cooperative for the Blind in Kopernika Street. A visit from Ignacy Szneider's sister caused Celek's origin to be revealed. The police were called, and as a result, the man was arrested and the woman's documents were confiscated. The sister-in-law convinced the officers that she was not Jewish, and gave Klymko's address saying he was her fiancé. Jan confirmed her statement before the director of the cooperative and convinced him to return the documents.
The Szaniawskis sent all their acquaintances in need of identity documents to Klymko, who would selflessly supply them with papers. Among others, he helped Henryk Herbstman from Jarosław, who was hiding in Lviv at the house of Róża Mozol. Klymko pretended to be Róża's fiancé “so that no one would suspect she was hiding someone, because she was being harassed by her neighbours”, as he wrote in his testimony from 1993.
Klymko also extended his help to Nesia Koffer, who later became his wife. Nesia Koffer was born in Dorohychivka, Zalishchyky County, Ternopil Province, where her parents lived: mother Regina Koffler (née Lehrer) (1887–1943) and father Marek Koffler (1880–1943), who worked as a teller. Nesia graduated from junior high school in Lviv and in 1930 began her studies at the Faculty of Law at the Jagiellonian University.
When Lviv was occupied by the Germans, she found herself in the ghetto, which she would leave to collect parcels sent to the address of a retired teacher, Prof. Michał Badluk, living at 10 Ruska Street, which she then passed to her uncle Markus Lehrer from Tovste, who was imprisoned at the camp in Janowska Street. In his testimony from 1993 Klymko briefly described the circumstances of Nesia's rescue: “I saved the life of my wife Nesia Koffler, currently Anastazja Klymko, by buying her safety for 4,000 zloty a month for 10 months and providing her with hiding places in the houses of decent people”. When describing the circumstances under which she met Klymko at the home of Prof. Badluk, Nesia remarked that “I found it very moving that he offered me help delivering a package to my uncle”. In November 1942 Nesia smuggled her uncle, who was ill with typhus, from the Janowska camp and nursed him in the ghetto.
Nesia Koffler managed to escape from the ghetto on 23 January 1943. Initially she found shelter with Prof. Badluk. At that time “a cordial friendship [...] formed” between her and Klymko. On 17 April 1943 Jan moved her to a new hideout at the home of Karolina Jung (Regowska), and then Olga Lubiniec. It was also Klymko who arranged for her last hiding place at Wasyl Majkut's home, where she stayed for 10 months until liberation. He obtained a Kennkarte with the last name “Tysowicz” for her, which allowed her to move around the city and pay for her room and board.
All testimonies from Jews whom Klymko helped in Lviv mention his great commitment. In 1972 Maria Hofman summarized Klymko's attitude: “putting his own life at risk, he looked after participants of the resistance movement, guided in his actions by strong anti-fascist beliefs and profound patriotism”. As Nesia Koffler stressed in her testimony from 1993, “His motive for helping me and others was simple human compassion. It was common knowledge that assistance such as he gave me and others was punishable by death”.
Nesia's parents and her grandmother Estera Lehrer (1863–1943) perished in the Holocaust. Her sister Amalia Rosestock (1912–1943) and niece Nina Rychtman met the same fate. Markus Lehrer on the other hand returned to Tovste, where she stayed until liberation, and then left for Chicago, where he died in 1988.
After the liberation of Lviv in July 1944 Nesia Koffler worked as an attorney. In July 1946 she and Klymko were repatriated to Poland. They initially settled in Gliwice, where they were married in September 1946 and Nesia changed her name to Anastazja Klymko. She worked at the Katowice Branch of the Special Commission as a legal advisor and from 1950 as an attorney in a law firm. Klymko retired in 1975 and his wife in 1981. She was active in the Socio-Cultural Association of Jews in Poland (Polish: Towarzystwo Społeczno-Kulturalne Żydów). Ella Klimko returned to Prague and got married again, to the lawyer Kurt Deutch.
Ignacy Szaniawski and his wife Julia continued to use their “Aryan papers” after the war. In 1945 they repatriated to Warsaw, where Szaniawski joined the Polish Workers Party (Polish: Polska Partia Robotnicza, PPR). He worked at the Ministry of Education, and from 1946 the Ministry of Foreign Affairs, where he headed the Bureau for Jewish Affairs. In 1948 he earned his PhD from the Faculty of Humanities at the Jagiellonian University. After leaving the Ministry, Szaniawski worked at the School of Education at the University of Warsaw and headed the Faculty of Theory of Technical and Vocational Education at the University of Warsaw. His wife worked as a Polish language teacher at the Secondary Technical School of Electrical Engineering. Ignacy and Julia Szaniawski raised two sons: Józef (1944–2012), a journalist and political scientist, and Ryszard (b. 1947), a doctor of biochemistry and chairman of the Board of the Foundation of the St. Christopher Oncological Hospice in Warsaw.
The Klymko couple remained in touch with Julia until her death in 1971 in Skrzelów in Lower Silesia. Klymko also maintained a friendly relationship with his sister-in-law in Prague and, after her death, with her second husband.
In 1996 Anastazja Klimko was interviewed by the USC Shoah Foundation. On 27 January 1997 the Yad Vashem Institute decided to award Jan Klymko the title of Righteous Among the Nations.