Thermo Sudoku

Thermo Sudoku. Along each thermometer shape, digits must increase from the bulb to the tip.

How to play

Fill the 9×9 grid so every row, every column, and every 3×3 box contains the digits 1 to 9 with no repeats — the classic Sudoku rule. Thermo Sudoku adds one twist: Along each thermometer shape, digits must increase from the bulb to the tip.

Every Thermo Sudoku puzzle is free to play in your browser — no ads, no sign-up, and it works offline.