A Vizier of Ilkhanid Abu Sa'id, named Yusuf Quhadhi built the Jameh Mosque of Varamin.

At the turn of 14th century, Varamin started to decline due to Timurid Empire armies' invasions.

In 1405, Ruy González de Clavijo described the city as mostly deserted, although during early Timurid rule, a minor restoration was applied to the Jameh mosque and Imamzadeh Hosein Reza was built.

According to the information of the State Meteorological Organization of Iran, the long-term average annual rainfall of Varamin is around 107.5 mm[13]During the Mongol Ilkhanate, as a result of the economic growth in the region, Varamin became an urban center and most of the significant historical monuments of this city belong to this period.

Including: The most famous building of the city, the Jameh mosque's construction began during Öljaitü's reign and completed in during his son's rule in 1322.

[17] Other than above buildings, mausoleums of Hosein Reza, Sakinehbanu, Kowkab a-ddin, Seyyed Fathollah, and Zaid Abolhassan are other historical monuments.

Additionally, historians have mentioned the Razaviyeh historical madrasah adjacent to the Jameh Mosque, also Varamin Castle, 1500 feet from the Jameh Mosque, has also been a noted by travelers, both the madrasah and citadel do not also exist today.

[20][21] Varamin Oil-extracting factory was built in 1938–1939 and is the first producer of vegetable oil in Iran.