Gangoh in Saharanpur recorded the highest polling percentage of 57.8, while the Lucknow Cantt seat recorded the lowest at 27.1 per cent.
The polling percentage in Rampur that witnessed a high-powered campaign remained at 39.3, which is comparatively low.
Experts attribute the poor polling percentage, despite pleasant weather throughout the state, to the growing indifference of voters towards the political system.
"The results of the by-elections will not change the complexion of the state Assembly and this could be a reason for the low voter turnout," said a BJP functionary.
In the UP Legislative Assembly, the BJP currently has 302 members, the Samajwadi Party 47 and the Bahujan Samaj Party 18. The BJP's ally Apna Dal (Sonelal) has eight legislators, while the Congress has seven MLAs in the House.
The by-elections were relatively peaceful and the release issued by the Chief Electoral Officer of the state claimed that there were no cases of violence, bogus voting, impersonation or booth capturing.
The by-elections to 11 Assembly segments were held in Gangoh, Rampur, Iglas (SC), Lucknow Cantonment, Govind Nagar, Manikpur, Pratapgarh, Zaidpur (SC), Jalalpur, Balha (SC) and Ghosi.
Of the 11 seats, the BJP and its ally Apna Dal had won 9 seats while the Samajwadi Party and the Bahujan Samaj Party had won one seat each in the previous elections.
The SP, BSP and Congress are contesting all the 11 seats, but their leaders did not campaign as vigorously as the BJP.
( With inputs from IANS )