In Meteorological standards, a variation in temperature within +/ – 2°C is considered normal and is reported as no large change as that much fluctuation within 24 hrs can’t be termed as significant.
24hrs temperature variations in maximum or minimum over Panaji/Mormugao has mostly be within 1 to 1.5°C only.
Temperature over a region is affected by so many factors such as the wind direction and speed over that region, the content of humidity in the atmosphere of that region, the amount of clouding on the time, other atmospheric features such as circulations in different layers of atmosphere.
(1) As a basic rule if the lower level winds upto a height of around 1km from surface is coming from colder sides, a drop in temperature can be there, if winds are from comparitively hotter regions, temperature will rise. The variations in wind direction and wind speed within a season is quite normal
(2)In addition to that if there are some weather systems bringing moisture to different levels, it may result in clouding and generally inflow of moisture to middle or lower atmosphere brings down maximum temperatures and brings up minimum temperatures.
(3)Then there are systems like anticyclonic circulations which may result in subsidence of air over a region, this increasing maximum temperatures.
There are some of the reason, there could be a few more and it’s combinations.
For the variations in temperatures over Panaji, (1)&(2) has contributed mostly.