The variability of temperature and salinity along 11 degrees N and 12 degrees N sections in the Bay of Bengal during southwest monsoon months (July-September) was found to be large in the upper 200 m west of 83 degrees E and east of 90 degrees E, and up to upper 400 m in the central parts between 84 degrees and 89 degrees E. Coastal upwelling off Madras appears to be intense during August with a strong (40 cm sec sup(-1)) northward flow close to the coast. The associated northward transport in the upper 100 m (between 81 degrees and 82 degrees E) increased by 2.5 x 10 sup(6) m sup(3) sec sup(-1) from July to August. At the location of penetration of Arabian Sea High Salinity Watermass (T = 25 degrees C, S = 35.2 x 10 sup(-3) , delta sub(s.t) = 400 cl/t) doming of isolines of T, S and sub(t) (sigma-t) towards sea surface was noticed between 86 degrees and 89 degrees E only during August. The flow in this region was directed towards north with a volume transport of 5.5 x 10 sup(6) m sup(3) sec sup(-1) in the upper 100 m.