Rain Measure

I have been following the rain measurements at the Thai Meteorological Department (TMD) and can't agree with their readings.   Today heavy rain began shortly after 5:30 pm.   By 7pm TMD reported 5.2 mm (.20 inch) My own measurements were .25 inch during the first half hour.   By 7pm my measurement was .85 inch. Granted my own measurements are not scientific, but probably more accurate.

Sakon Nakhon