Your rain data there doesn't make any sense - the rain out of the console (raw rain) seems to be incrementing, but thedaily value isn't incrementing by the same amounts.
First quit WeatherCat and the check to make sure the rain on the console isn't incrementing, if it is, you'll need to check the hardware. Assuming that's fine, reboot the machine then run WeatherCat - if the problem's gone away, restore your data from yesterday's backup (Tools->Backups). If the problem still exists, take a look at the Live Data View (Tools->Live Data View) to see what your rain data is doing there and post back with info about what it's doing there, on the gauges and graphs.