Weather & climate glossary
Plain-language definitions of the terms Thermograph uses to grade the weather.
Climate normal
The typical value of a weather metric for a place and time of year, averaged over decades.
Percentile
Where a value ranks within a distribution: the 90th percentile is warmer than 90% of days.
Temperature anomaly
How far a temperature departs from normal: the difference from the long-term average.
Feels-like temperature
What the air actually feels like once humidity and wind are accounted for.
Heat index
How hot it feels when humidity is factored into the air temperature.
Wind chill
How cold it feels when wind is factored into the air temperature.
Absolute humidity
The actual mass of water vapor in the air, in grams per cubic meter.
Reanalysis (ERA5)
A gridded, physically-consistent record of past weather for anywhere on Earth.