I can't even begin to count how many times I've had this conversation with Siri.
"Hey Siri, is it going to rain?"
"It doesn't look like it's going to rain today."
"It's raining right now."
"It isn't raining right now."
"Hey Siri, is it going to rain?"
"It doesn't look like it's going to rain today."
"It's raining right now."
"It isn't raining right now."
I live in Toronto, Canada, which stretches about 40km east-west, and 20km north-south:
If the west-end (Sherway) gets hit with rain, but the east-end is dry, did it rain "in" Toronto when folks in Scarborough didn't experience it? Was the forecast wrong?
If it snows in North York but is dry at Billy Bishop, was the precipitation forecast "wrong" for one particular group of people?
Meanwhile the Google Weather app constantly insists I live in Frankfurt while I'm in Warsaw.
On a serious note I'm dealing with this as well - I live in a middle-sized city in the centre of the country, not in Kraków!
The technical limitation would be on the weather data size: what is the granularity/resolution of the radar data on where rain is actually falling?
* https://en.wikipedia.org/wiki/Canadian_weather_radar_network
Further: what is the geography of the area, and how does that effect things as well? Toronto specifically has (a) all sort of heat island effects, (b) certain areas are effected by the lake and how weather systems cross it at certain angles, and (c) has enough of an elevation change going north of the lake (e.g., Niagara Escarpment) that there are a few ˚C change in temperature that makes the differences between snow and rain.
So unless you are sitting next to the the weather station that Siri is getting data from, I would not expect it to know 100% of the time.
I don't, but as a result, I expect it not to guess.