The first thing to note about Mumbai weather is that it never gets 'cold' since there is no real winter in the place. In fact when the minimum temperature goes below 15 degrees (all temperatures in celsius) it is considered 'chilly'. Most of the year the weather is hot and humid throughout the day (and night). Broadly speaking, there are three weather patterns in Mumbai: the cooler, dry season, which is the months of December through February; the two hot and humid seasons, one from mid March to mid June and then again during September-October; and the monsoon period, from mid June through August. The intervening periods have transitory weather. Obviously, by far the best time to visit Mumbai is during December-February especially the first two months of the year when it is quite pleasant outdoors throughout the day. The monsoon period sees very heavy rains and while the place cools down it is wet, wet, wet which limits outdoor activity. The two summer seasons, pre monsoon and post monsoon see a combination of day temperatures in the mid thirties with humidity above 70% with day lows in the upper twenties with the same level of humidity.