Hirakud recorded 42.4 degrees Celsius, Jharsuguda was at 42.2, and Bolangir at 42.1.
State capital Bhubaneswar sizzled at 40.4 degrees Celsius, while it was 40 degrees in Cuttack city.
The weather office said hot and humid conditions are expected to prevail in most parts of the state on Tuesday.
Thunderstorms with lightning are likely in Malkangiri, Koraput, Rayagada, Gajapati, Mayurbhanj, Balasore, and Ganjam, it said. PTI BBM BBM SOM