Why do most online weather forecasts only state the chance of rain as a percantage, without stating the expected rainfall in millimetres? If there’s a 90% chance of rain, it matters a lot whether it will be 0.5 or 5mm

Question

Why do most online weather forecasts only state the chance of rain as a percantage, without stating the expected rainfall in millimetres? If there’s a 90% chance of rain, it matters a lot whether it will be 0.5 or 5mm

In: 29

Answer 1

Probably because most people care more about whether it will rain or not than about how much rain there will be. If you’re planning an outdoor activity or wondering whether to bring an umbrella, 5mm and 50mm are the same amount of problem.