Thermometers

How to play

• Tap a cell to fill its thermometer up to that cell; tap the top of the mercury to drain it back.
• Mercury always fills from the bulb (●) along the tube — never with gaps.
• Each outside clue is the number of filled cells in that row or column.
• Every board has exactly one solution, machine-verified before publication.

A gentler cousin of nonograms — pure counting logic, no guessing. Sister puzzles: Gridlings.

FAQ

How do you play Thermometers?

Fill mercury from each thermometer's bulb continuously along its tube so that every row and column contains exactly as many filled cells as its clue says. Tap a cell to fill its thermometer up to that point; tap the mercury's tip to drain it back.

Is there a new Thermometers puzzle every day?

Yes — a new daily board goes live at 00:00 UTC, the same board for every player worldwide, with streak tracking. Unlimited free play in three difficulties and a full archive of past dailies are also free, with no account and no ads.

Can Thermometers be solved without guessing?

Yes. Every published board is machine-verified before release: a solver proves exactly one solution exists and is reachable by logical deduction, so there is always a provable next step.