How to read a weather forecast: rain chance, feels-like and wind
Three numbers on every forecast page are easy to misread. A short guide to what they mean and how far ahead to trust them.
Rain chance is about likelihood, not amount
A 60 percent chance of rain does not mean it will rain for 60 percent of the day, or over 60 percent of the city. It means that, in situations like this one, measurable rain falls at a given spot about six times out of ten. A 30 percent chance with a heavy thunderstorm can still bring a soaking, and 80 percent can mean a light drizzle. Read the chance together with the millimetres shown alongside it.
Feels-like and wind
The feels-like temperature combines air temperature with humidity and wind to estimate what your body experiences. In humid coastal cities such as Lagos, Dar es Salaam or Mombasa, it can sit several degrees above the thermometer reading, and that is the number to plan around. For wind, speeds above about 38 km/h make driving and small boats harder, and gusts above 55 km/h can bring down branches and loose roofing. Those are the thresholds AfricaMeteo uses for its strong and damaging wind alerts.
How far ahead to trust it
Forecasts are most reliable for the next one to three days and become steadily less certain after that. Days five to seven are best used for trends: is it getting hotter, is a wetter spell coming? Tropical thunderstorms are hard to place exactly even a day ahead, so in the rainy season treat the daily rain chance as a guide to how unsettled the day will be rather than a promise about your street. Check again on the morning itself.