Learn How Weather Records Work
4 plain language explainers on how weather records are measured, counted and ranked, written for readers with no background in climate science. Each one answers its question in the first paragraph and links to the data pages behind it.
Weather Record Basics · How Records Work · Tropical Cyclones · Heat, Cold, Rain and Snow
Weather Record Basics
1 explainerWhat a weather record is and how stations measure it.
- What Is a Weather Record and How Is One Set? A weather record is the highest or lowest value a station has measured for a day, a month or all time. Learn the types, timescales, margins and limits.
How Records Work
1 explainerHow records are set, tied, ranked and kept over time.
- What Is a Record Tie and How Do We Count One? A record tie is a new value equal to the standing weather record at the recorded precision. Learn why ties happen, how we label them and why they score lower.
Tropical Cyclones
1 explainerHow tropical cyclones are tracked, named and measured.
- What Is Accumulated Cyclone Energy (ACE)? Accumulated cyclone energy adds up the wind energy of a tropical cyclone over its life. Learn the formula, units, limits and how we use it.
Heat, Cold, Rain and Snow
1 explainerHeat waves, cold outbreaks, extreme rain and heavy snow.
- What Is a Heat Wave and How Do We Define One? A heat wave is a spell of unusually hot weather lasting days. Learn the common definitions, why they differ, and how we detect events from clusters of records.