Level 4

Thermo Sudoku

Enter the world of exotic variants with increasing numbers.

The Thermo Rule

In addition to normal Sudoku rules, Thermo Sudoku introduces thermometer shapes to the grid.

The Rule: Digits must strictly increase in value as they move from the bulb (the circle) to the end of the thermometer.

Why it's amazing

Because the numbers must strictly increase, long thermometers severely restrict what numbers can go where! For example, a thermometer that is 5 cells long cannot have a 5 in the bulb, because you'd run out of numbers before reaching the tip (5 -> 6 -> 7 -> 8 -> 9 is the max!).

Thermo Sudoku Rule Diagram

Interactive Challenge