Weather is hyper local. In the US precipitation data are generally available at 1km grid resolution through combination of radar, satellite, and ground truth gauges — these are good areal estimates but pretty much always very bad point estimates. There can be problems in data availability, and quality due to all sorts of things like bird migrations, clouds, and gauge malfunctions. Collecting your own data is cheap and easy.
As farmers, my family has always been interested in the weather for good reason. We have a few rain gauges about a mile apart and the difference between them is significant. You might get a tenth of an inch in one place and a half an inch a mile away.
The synthetic precipitation data might be useful on a large, average scale, but it usually doesn't actually provide a particularly accurate measure of what actually happened on your land.
