What does it mean to dream about thermometer?
A thermometer often points to taking the measure of a feeling or a state of things, so notice whether it read calm, feverish, or out of bounds.
Four ways to read it
Each reading below comes from a named tradition and a cited source, so you can see where it came from and decide what fits your dream.
Freud
Freud would read the rising and falling reading as a gauge of inner heat, the temperature of feeling and desire. A spiking thermometer can carry the pressure of an emotion running high.
After Freud, The Interpretation of Dreams (Brill trans., 1913), public domain.Jung
Jung might see the thermometer as a measure of how charged or how cooled a part of your inner life has become. Its reading can show the heat of a conflict or the chill of a withdrawn feeling.
Jungian concept (our summary).Modern
Continuity ties a thermometer to waking thoughts about health, mood, and gauging how tense a situation has grown. A fever reading often echoes a real worry about something running too hot.
Continuity hypothesis (our summary).Mythological
The measuring of heat and fever sits within the old lore of the body's humours, where balance of hot and cold was thought to govern health and temper. To run too hot was to be out of one's right order.
Rosmerta Publishing editorial synthesis (after Brewer; Frazer).