All schools in Ranchi and Khunti districts will also remain closed on Friday as the IMD has forecast heavy rainfall, an official said.
Schools in Ranchi and Khunti remained closed on Thursday due to incessant rainfall from Wednesday.
The IMD has issued a 'red' alert (heavy to extremely heavy rainfall) for Ranchi from 8.30 am on Thursday to 8.30 am on Friday.
The Ranchi district administration on Thursday decided to extend the holiday for one more day due to forecast of heavy rainfall on Friday, he said.
"In view of the possibility of heavy rainfall and for the safety of students, Ranchi Deputy Commissioner Manjunath Bhajantri has issued an order to keep all categories... of schools in the district, from class KG to Class 12, closed on June 20," the notification said.
In case of non-compliance, the concerned school will be held accountable under relevant sections of the Disaster Management Act, 2005, it stated.
All schools including government and private up to class eight to remain closed in Saraikela-Kharswan district on Friday, according to an order issued by the district administration.
Ranchi recorded 153.3mm rainfall from 8.30 am on Wednesday to 8.30 am on Thursday.
Heavy rainfall across Jharkhand left four people, including two schoolboys and a 10-year-old girl, dead in three places, besides causing infrastructural damage in several districts, officials said on Thursday.
The southwest monsoon, which arrived in Jharkhand on Tuesday, covered the entire state on Wednesday, bringing widespread rainfall that is likely to continue across the state till June 20, an official said.