Chegdomyn was founded in 1939, with the beginning of black coal mining in the area. At the same time, construction of a branch line from the Trans-Siberian Railway at Isvestkovaya to Chegdomyn was begun, although it was dismantled during World War II and its tracks reused in construction projects closer to the front.
After the end of the war, the railway was rebuilt, opening in 1951. Coal mining resumed in 1948, and Chegdomyn was granted urban-type settlement status in 1949.
Chegdomyn has a monsoon-influenced humid continental/subarctic climate (KöppenDwb/Dwc) with severely cold, dry winters and rather warm, rainy summers. Temperatures in the area of the city typically change by over Шаблон:Convert over the course of the year, with a daily average of Шаблон:Convert in January, compared to Шаблон:Convert in July.
Chegdomyn is as cold a climate gets in the world while still meeting the requirements for not being subarctic. This is due to the location being far enough inland to experience severe cold from the Siberian High in winter and to build up warmth in late spring, while at the same time being near the coast to extend summers. The autumn fall of temperatures is sizeable, with August to December having a mean monthly drop of Шаблон:Convert. In spring, the gain is almost as rapid. With peak winter being quite dry, the most snow accumulation usually later in the season due to the weakening of the high-pressure systems in favour of more humid air masses. In summer, temperatures are often moderated by the frequent rainfall, but are still warm for the latitude at about Шаблон:Convert average highs.
The settlement's main industry remains coal mining by Urgalugol, now owned by the Siberian Coal Energy Company. There is also some timber production in the surrounding area.
