Why rain probability matters for clothing advice

Rain probability is probably the most misread number in weather forecasting. A 60% chance of rain does not mean it will rain for 60% of the day, and it doesn't tell you how hard it will rain when it does. What it actually means: in 6 out of 10 similar weather situations, rain occurred somewhere in the forecast area during that period. Anything above 50% means rain is more likely than not.

When it actually changes what you should wear

For a short trip the number matters less. Running to the shops and back? You'll probably be fine even at 60%. But if you're spending several hours outside, the calculation shifts. Wet clothing loses much of its insulating ability, which means rain isn't just uncomfortable: it can meaningfully lower how warm you feel for the rest of the day.

The missing piece is always intensity. A 90% chance of drizzle is a different decision from a 90% chance of a downpour. Rain probability alone doesn't distinguish between them, which is why the amount of rainfall (in mm per hour) is a separate piece of information worth checking.

What rain probability means for clothing advice

KorteBroekAan.nl shows rain probability as context alongside the clothing recommendation. High probability is a signal to think about a waterproof layer or at least to keep one accessible. It's also worth knowing that wet clothing against the skin accelerates heat loss, so a rainy 15°C day can feel considerably colder than a dry 15°C day even at the same wind speed.

For more on what happens when clothing gets wet and how rainfall intensity changes things, the Weather Explained section has articles on both. The post on temperature alone also covers why a single number rarely tells the full story.

Further reading

Related articles in the Weather Explained section:

• Why rainfall amount matters
• Why drizzle feels different from a shower
• Why wet clothing makes you cool faster
• Dressing for changeable weather