Vesikivellätermillä

Vesikivellätermillä is a Finnish term that translates literally to "water stone thermometer." It refers to a simple, often improvised, method for estimating water temperature using a stone. The technique involves submerging a stone in the water for a period of time and then touching the stone to gauge its temperature. By comparing the stone's warmth or coolness to one's own perceived body temperature or to a known ambient temperature, a rough estimation of the water's temperature can be made.

This method is not precise and is highly subjective, relying on the individual's sensory perception. It is often employed in informal settings, such as when swimming or fishing, where an exact temperature reading is not critical. The effectiveness of vesikivellätermillä depends on factors like the stone's material, its size, the duration of submersion, and the ambient air temperature. Historically, before the widespread availability of accurate thermometers, such empirical methods were more common for making practical judgments about water conditions. While no longer a scientifically valid measurement technique, the term vesikivellätermillä persists in some colloquial usage to describe this rudimentary approach to temperature assessment.