Why don't my rain forecasts match up – differences between radar display and actual precipitation

It can be frustrating when the rain forecast doesn't match the actual weather. We'd like to explain why this can happen and which factors play a role.

Differences between rain radar and forecast

The rain radar shows real, measured radar data for the first two to three hours. After that, the display is based on calculated forecast data. The adjacent minute forecast, on the other hand, is calculated exclusively using weather models. This means that both systems work technically differently and can therefore show different results – even if both are based on current data.

Why do rain forecasts change in the short term?

Particularly with showers and thunderstorms, weather conditions can change very quickly. Rain cells can form anew, weaken or change their path. As a result, forecast precipitation may not occur, may start later or the amount may be underestimated.

False echoes in rain radar

Sometimes the radar shows precipitation even though it's dry where you are. These can be false echoes – reflections of radar beams off mountains, buildings or other obstacles that are incorrectly interpreted as rain.

What can you do?

For short-term planning, we recommend using the minute forecast and the rain radar in combination. Please note that longer-term forecasts (beyond 3 hours) are less accurate. For critical decisions, you should use multiple sources of information.

If you notice systematically inaccurate forecasts, please feel free to give us feedback – this helps us improve our services. You can contact us at support@weather24.co.uk.