Hot day

In the northern plains of the country, dust in suspension occurs in many years for several days, bringing minimum temperature much higher than normal and keeping the maximum temperature around or slightly above normal. Sometimes increase in humidity also adds to this discomfort. Nights do not get cooled and become uncomfortable. To cover this situation, hot day concept has been introduced as given below:
Whenever, the maximum temperature remains 40ºC or more and minimum temperature is 5º C or more above normal, it may be defined as Hot Day, provided it is not satisfying the heat wave criteria given above. Criteria for describing Hot Day for coastal stations.

When maximum temperature departure is 5º C or more from normal, Hot Day may be described irrespective of the threshold value of 40º C. If the threshold value of 40º C is reached Heat Wave may be declared.

When a station satisfies both the Heat Wave and Hot Day criteria, then Heat Wave should be given higher priority and be declared.