Weather or climate: what's the difference?
The weather is the mood of the day; the climate is the character over the long term.
Contents
“If it’s cold today, where’s the warming?” We hear this sentence often. It rests on a confusion between two time scales.
Mood and character
A simple image: the weather is a person’s mood on a given day — they may be in a bad mood even though, deep down, they are a cheerful person. The climate is their character, what emerges over the years.
A cold day does not disprove warming, just as a burst of anger does not make someone a bad-tempered person.
A question of scale
| Weather | Climate | |
|---|---|---|
| Time scale | hours to days | decades |
| Question asked | “what will the weather be tomorrow?” | “what to expect in general?” |
| What is observed | an event | a trend |
The weather is unpredictable beyond a few days. The climate, on the other hand, is described by robust trends, precisely because we average over the long term and smooth out the ups and downs of daily life.
The classic trap
Confusing the two leads to two symmetrical errors:
- taking an isolated cold spell as “proof” that nothing is changing;
- taking a single heatwave as “proof” on its own.
An isolated event proves nothing by itself. What matters is how the frequency and intensity of these events evolve over the decades.
Going further
It remains to be seen what makes a country more or less exposed to these changes: Why Tunisia is particularly exposed