The present study was carried out to study the effect of varied hydrothermal regimes on phenological events and different phenophase thermal time requirement of summer green gram (Vigna radiata L. Wilczek) cv. SML-134 raised during summer season 1999 and 2000. The treatments included three dates of sowing viz. 12th April (D-1), 19th April (D-2) and 26th April (D-3) (main plots); three irrigation levels viz. 0.5 IW CPE ratio (I-1), 0.75 IW CPE ratio (I-2) and 1.0 IW CPE ratio (I-3) (sub plots); and mulched (M-1) (@ 5t/ha of wheat straw mulch) and unmulched crop (sub-sub plots), in a split-split plot design. Early sown, frequently irrigated and mulched crop showed delayed flowering and maturity than other corresponding treatments. The response was ocular in 1999 than that of 2000 due to receipt of frequent rainfall at reproductive phase of the crop.