Understanding the variability and change of monsoon onset is of the utmost importance for agriculture planning and water management. The sudden onset of the South China Sea summer monsoon (SCSSM) is one of the most spectacular phenomena and has a profound societal impact. Kajikawa and Wang (2012, hereinafter KW12) detected a significant change in the mean onset date of the SCSSM around 1993/94: the epochal mean onset date is 30 May for 1979‐93 and 14 May for 1994‐2008, so the onset date in the post-1994 epoch has advanced by 16 days. Chen (2015, hereinafter C15) has carefully checked the KW12 finding by using a different reanalysis dataset and extending the analysis period from 1979‐2008 to 1979‐2012. The result of C15 confirms that the KW12 finding is robust even during the extended period after 2008. We appreciate this contribution from C15. The fundamental science issue hereis why the SCSSM onset date advanced remarkably after 1993/94. The comment of C15 states in its abstract that Kajikawa and Wang (2012) ‘‘attributed this [onset] change to enhanced tropical cyclone (TC) activity and intraseasonal variability (ISV) related to 30‐80-day and 10‐25-day anomalies in the second epoch.’’ This misleading statement motivated C15 to assess the individual impact of TCs and ISV on the change of the SCSSM onset. We would like to start our reply by correcting C15’s misunderstanding of the work of KW12. The fact is that KW12 attributed the root cause of the interdecadal change of the SCSSM onset to decadal changes in the lower boundary anomalies. They pointed out in their abstract that ‘‘the advanced SCSSM onset is rooted in the decadal change of the SST over the equatorial western Pacific.’’ KW12 further indicated that ‘‘the advanced onset during the second epoch is affected by the enhanced activity of northwestward-moving tropical disturbances from the equatorial western Pacific’’(italicsaddedforemphasis).Heretheyhighlighted