THIRUVANANTHAPURAM: The southwest monsoon is expected to intensify by the middle of this month, the Indian Meteorological Department said. The monsoon is expected to return by July 8 and heavy rains are expected by July 15. Prior to that, some parts of the state are likely to receive isolated heavy rains. The rainfall (408.44 mm) received by the state in June this year is the lowest in 39 years.