The wondrous magical weather wand casts an enchanting spell of light. A way to see what is normally felt.
In less magical terms, I have an Arduino pro mini with a temperature sensor (currently a TMP36) and a RGB LED. The Arduino checks temperatures and sets the color of the light based on the temperature.
The early version of this used a temp to color table (like the temperature map project) that would for example set to the light yellow if above 70º or to blue if below 30º. However it would be pretty unlikely to encounter that wide of a temperature range within a space so instead of re-tuning the table for every location I wanted to have it set it's own range.
The wand takes and averages the temperatures it sees and sets the color to normal (green) based on that average. The color changes basedon the number of standard deviations from that average. ie: 2+ stddev is red
Also got it to work with NeoPixels, because one light might just not be enough sometimes.