The storm killed people in Sonebhadra, Mirzapur and Bhadohi where many hutments collapsed and tin sheds were blown away in the wind. Over a dozen people were injured.
Officials said a large number of cattle were killed in Chapka, Sohadwal, Nakpur and Doriya villages of Sonebhadra district.
The dead include three youth, who were killed when lightning struck them at Siddharthanagar. One person each were killed in Maharajganj, Sant Kabeernagar and Gorakhpur.
The details of the dead in other places was not immediately known.
Officials said rescue and relief operations have been set in motion. At many places uprooted trees blocked major roads and they were being sawed off to clear the way for traffic.
Mango harvest has also been destroyed at many places.
The regional met office told IANS that dust storms and lightning with some rains could occur at many places in the state.
Showers late Sunday brought down temperatures in some places, but the unrelenting heat is likely to continue.