Comment by strangegecko
17 hours ago
I regularly encounter days when today's forecast is wrong and even in conflict with the current situation.
E.g. the weather app tells me there's a drizzle all day and currently and yet it's entirely dry. The opposite happens too.
Days of rain often shift in increments of days one or two days before as well.
I'd say it's location specific how accurate predictions are.
Mostly that might be down to micro climate and similar highly regional variation in weather.
Here in Berlin, predictions that it will rain or when it will rain are often too pessimistic because the city is a bit warmer and drier than the surrounding areas, which is where the airports are. Tegel, now closed is no the North West, Brandenburg airport is on the South East. They are about 20km apart. The long decommissioned Tempelhof is actually in the middle of the city but I doubt that there still is a weather station there.
Airports are the big consumers of, and important sources of weather data used for making predictions (in addition to satellite data, and weather stations elsewhere). It's more important that the predictions are correct there than 10-15 km away in the downtown areas.
Additionally, many weather apps aren't really precise about where their focus is. You set the city typically; not a postal code. So they'll predict it will rain in Berlin. But it's a big city and that doesn't mean it's going to rain everywhere in the city. It won't do neighborhood by neighborhood predictions. It's technically correct even if not a drop falls where you are. And of course professional users of weather predictions mainly care about the type of weather they need to plan for, which for airports is things like Thunderstorms, poor visibility, etc.
For short term planning, weather radar apps are popular here. Great stuff for guestimating whether you can get home by bike without getting caught up in a big shower. Thunderstorms are very common here throughout the summer but you can see the systems moving west to east hours in advance on the radar apps.