India, May 12 -- Large parts of northern and eastern India are expected to be rainy this week, according to the forecast issued by the India Meteorological Department (IMD) on Monday. This follows similar weather patterns in April and May so far. This suggests that this summer season is likely to be one of the cooler ones. How cool exactly? The gridded data of the IMD shows that this is the 18th coolest summer since 1951, the first year for which IMD has published gridded data. However, it appears even cooler if one excludes the early part of the summer months, when temperatures are usually low in absolute terms.

Before discussing summer temperature trends further, however, it is important to note that the IMD has not clearly defined a s...