incorrect presentation of the past weather

I'd like to report the inaccurate presentation of the past weather on your maps which happens as far as I can see rather occasionally but is quite annoying and actually undermines your credibility. While the future weather predictions (even for the next few hours) may always be incorrect, there is no excuse, in my opinion, for not showing the PAST weather incorrectly.

I'm based in Wrocław (Poland) and your rain map shows clear, although light rain (up to 0.4mm) yesterday (7.09) between 4-5pm, widespread over quite a large area, far exceeding the city borders. I can reassure there was no rain AT ALL in those hours, at least in the east of Wroclaw, so your data is clearly wrong.

And it has happened at least occasionally in the past. I remember one day last winter with quite heavy and widespread snowfall (with well over 1cm thickness, as snow ploughs were out on the streets working) which went on for quite a few hours, while your snow cover maps claimed ZERO snow cover - and never rectified. Curiously, when the snow had mostly melted a couple of days later, you did show some snow cover but only at that point - not when it actually snowed heavily before!

I'm not checking the past weather frequently (only when I need it for some reason, like to see if it rained overnight and how much) so such mistakes may be more frequent actually.

And what is here additionally annoying - some months ago you started to obstruct the access to the weather projection for over 7 days ahead with the message on the screen asking for financial support. How can anyone be convinced to do that if even the past weather isn't always displayed correctly???

Breslaviano
You need to look at the radar and its history. It shows actual measurements. Even then, however, it does not represent precipitation exactly at ground level — the radar measures precipitation at an altitude of around 2 km, and in some cases it may evaporate before reaching the ground.

Ventusky is a visualization platform. And the reality is that nobody in the world knows exactly what the weather was at every location on Earth at any given time in the past. What would such information even be based on? Weather station networks are sparse, radar coverage is not available everywhere and does not measure everything, satellites cannot determine precipitation precisely, and so on. You are asking for something that simply cannot be known with that level of accuracy.

Ventusky
Thanks for your reply. I need to admit I'm a lay person in this matter, but I'm still surprised to hear that those precipitation data may not refer to actual rainfall on the ground. As such they are of little practical use - who cares (unless of course you are a scientist studying some weather patterns at depth) about precipitation 2km above, if it never materialised?

And then you say that measurement facilities are scarce - well, that may be true for some, perhaps many other places, but incidentally there is a weather station of a local university literally some 0.5km away from my home.
I've just checked their website and the precipitation graph on it - it doesn't show any rainfall yesterday - correctly. So, is it not included in your database(-s) or what else would be the reason? They don't seem to show any weather maps (to tell how extensive the rainfall, or lack of it, was) as they provide info just for their particular location. But a resource like yours, summarising all such data on a global scale should include theirs as well, shouldn't it? (it still wouldn't provide a perfect extent of the rain on the map, but at least the map wouldn't claim that it did rain in a place where it definitely didn't). And we are talking about a rather big city in central Europe here, not some remote location in e.g. Africa or Siberia where the data may be indeed very sparse.

The link is below if you want to check them (I can't see an English version but hope you can cope anyway)
https://www.meteo.uni.wroc.pl/pogoda-on-line/

Breslaviano
Our map is primarily based on radar measurements, and yesterday the rain simply evaporated before reaching the ground. In for example 80% of other cases, this does not happen and the map is accurate.

It is certainly not a product intended for scientists. Just because a product does not have a 100% correlation with measurements at ground level does not mean it is useless. You simply need to understand its limitations.

If you want precise weather information for one specific location, you should monitor a local weather station, and you were right to find one at the university. It is simply not possible to cover everything in one place.

Ventusky
Ok, I see. Just thought you collate all the available data, not just from radars, therefore weather stations would also be included.

I know the product is not for scientists. I only referred to the fact that in those particular cases where rain doesn't reach the ground, it may be of interest only to them (to study with more sophisticated methods that I have no idea about) as none of us down here can see such precipitation or be affected by it.

And I definitely never said what you do is useless. I look at those maps almost every day to see what's happening in the wider world weatherwise (something that most other services I know do not offer or at least are not so transparent). And exactly because of that, seeing that it works mostly fine, wanted to find out why it isn't always the case.

I now understand a bit better those limitations that you have and will only get back in the future if there happens to be any serious discrepancy between the records and the reality (that snow cover I mentioned earlier seems to be such case but it's now too late to dwell on it).