That thermometer in the center, it is 23 cells long, and yet still contains only digits between 1 and 9 inclusive. 23 cells is one of the longest slow thermometers possible within a standard 9x9 Sudoku grid, although I’ve heard rumors of even longer. I think to be longer, the thermo has to cross itself, which can lead to some confusion. There are a few different ways to arrange such long thermometers, and this is one.
Rules:
Normal Sudoku rules apply.
Digits on thermometers either increase or remain the same from bulb to tip. Coloring is cosmetic.
Estimated difficulty: 1 out of 5
Solve on SudokuPad