Presently, satellite-derived precipitation estimates have been widely used as a supplement for real precipitation observation. Detailed evaluations of a satellite precipitation estimate are the prerequisite for using it effectively. On the basis of the daily precipitation observation from 91 rain gauges throughout Thailand during a 15-yr period, this study evaluated the performances of daily precipitation data of Climate Prediction Centre morphing technique (CMORPH) and TRMM (3B42 version 7) in an interpolating-grid-points-into-stations manner. This filled in the deficiencies of the current evaluations of TRMM-3B42v7's performances over Thailand made the first evaluation of CMORPH in this region and showed the first report of relative performances of two datasets.

For the entire Thailand, a total of 35 factors (including precipitation intensity, spatial distribution pattern, and duration/interval) were used in the evaluation. It is found that only 12 of them (including annual and monthly variations of precipitation, conditional rain rate in the rainy season, rainfall interval in an entire year, non-precipitation days, etc.) were reproduced credibly (i.e., the relative error was less than 20 %) by the two datasets. Both TRMM-3B42v7 and CMORPH displayed similarly poor performances in representing the intensity and spatial distribution of extreme precipitation. Comparisons based on the 35 factors indicate that TRMM-3B42v7 displayed a better overall performance than CMORPH for the entire Thailand.

For each region of Thailand, CMORPH/TRMM-3B42v7 showed different performances in different regions (a total of 19 factors was used). The CMORPH/TRMM-3B42v7 data made credible estimates over all five regions of Thailand in terms of daily precipitation intensity and monthly variation of precipitation, whereas, in terms of precipitation day fraction, conditional rain rate during the dry season, and interval/duration of rainfall events during the rainy season, it showed notable errors in all regions. Overall, TRMM-3B42v7 exhibited superior performances to CMORPH for the North, Northeast, East, and South of Thailand, whereas CMORPH and TRMM-3B42v7 displayed similar performances for the Central Thailand.