Is Bangalore Winter Getting Lost to Urbanization?

Is Bangalore Winter getting warmer? A question for which most old timers of Bangalore would say a convincing yes.  “Bangalore Winter is no more as cool / cold as it used to be”, is something we hear often these days. So is there merit in this thinking or are we over reacting.

A couple of weeks back we had run a similar analysis for Chennai which pretty much showed there was a clear warming up of Winter in Chennai.  We have used the same NCEP Climate Forecasting System Reanalysis to understand how the temperatures have been changing since 1979.  As has been the case with Chennai the temperature trends seem to show a turn towards the worse since late ’90s / early 2000s’.  In the case of Bangalore the effect is even more visible compared to Chennai.  Bangalore Winter has been getting fairly warmer since mid ’90s.

If one were to draw a trend line of the Average Maximum temperature for the month of February the increase is almost a degree and a half between 1979 & 2015. This clearly indicates the days getting hotter in Bangalore Winter effect seems to be fading away as indicated by the temperature charts. Since 1994 the average maximum temperature for the month of February has not gone below 29°C in Bangalore.

Bangalore_1

If one were to do an analysis for the minimum temperatures the results are very similar with the average minimum temperatures warmer by a degree or some compared to a decade or two back.  Once again the temperatures showing a jump from the mid ’90s.

Bangalore_3

Extending the analysis for the entire winter period the results are once again very similar. Clear increase in temperatures since late ’90s.  At this rate we could be soon calling “Bangalore Winter” as an extinct species.

The temperature trends indicate the increase happening from mid / late ’90s which coincides with the rapid urbanization that Bangalore has been going through.  But could we attribute it to urbanization based on coincidence or is it possible to confirm it with another variable?  In order to check if urbanization is the possible reason for the increase in temperatures we correlated the winter time maximum temperatures of Bangalore and Hosur, a town about 40 kms away, having very similar climate of Bangalore.

Bangalore_hosur

The chart pretty much shows the  possible effect of urbanization.  Hosur used to see marginally warmer day time temperatures a couple of decades the last few years slowly but clearly Bangalore is seeing warmer day time temperatures compared to Hosur.  In effect this pretty much confirms the effect of Urbanization.  Bangalore Winter is certainly loosing out to Urbanization.