"Hourly Rain Probability: Minute-by-minute weather forecast"

The percentage chance of rain is one of the most misunderstood pieces of information in weather forecasts. What does a "60% chance of rain" really mean? Here's a simple explanation.

What the Percentage Means

A 60% chance of rain does not mean that it will rain for 60% of the day, or that you have a 60% certainty of getting wet. Instead, it's a statistical figure used by meteorologists. It can be interpreted in two ways:

  1. Area-based method: It means that at a given time, 60% of the forecast area (e.g., your city) will experience measurable precipitation. So, you might be in the dry part of the city.
  2. Time-based method: It means that at any single point within the forecast area, there is a 60% chance of rain at a specific time.

Simply put: if the same weather situation occurred 10 times, it would rain at your location on 6 of those occasions. It's an indication of the confidence and coverage of the rain, not its duration or amount.

Chance of Rain vs. Amount of Rain

A high chance of rain says nothing about the amount of rain. There could be a 90% chance of a very light, brief drizzle that is hardly a nuisance. Conversely, there could be a 30% chance of an isolated but very strong thunderstorm that causes local flooding.

That's why it's important to always consider the chance of rain in conjunction with other information, such as the weather icon (does it show light drops or a thunderstorm?) and the expected amount of precipitation (in mm).

The Hourly Forecast for Precise Planning

The daily chance of rain is good for a general overview. However, for detailed planning, the hourly chance of rain in our app is much more useful. It shows you exactly which hour has the highest risk.

Example: The daily forecast shows a 70% chance of rain. However, a look at the hourly view reveals that this risk is almost exclusively concentrated between 2 PM and 4 PM. This tells you that your morning run and your evening barbecue will likely stay dry.

Even More Precise: The Precipitation Alert

For planning the next 60 minutes, the precipitation tile on the "Today" page is best. It is based on real-time radar data and can tell you with minute-by-minute accuracy if and when rain will start in the next hour. This is perfect for short-term decisions like a trip to the supermarket.