Number Theory: Going up, but Delhi Feb temp still below normal

The seven-day forecast issued on February 21 by the Regional Meteorological Centre of the India Meteorological Department in Delhi says that skies are going to be partly cloudy in Delhi from February 22 to February 24, with strong winds on the first two of those three days.

The skies have been clear in Delhi for the past week. Over the next seven days, it may not always be the case. The seven-day forecast issued on February 21 by the Regional Meteorological Centre of the India Meteorological Department in Delhi says that skies are going to be partly cloudy in Delhi from February 22 to February 24, with strong winds on the first two of those three days. However, the maximum temperature in the city-state is going to

People throng India Gate to witness pleasant weather in New Delhi.  (ANI file photo)

Why is February still colder than normal on average?

The reason for this is what happened in the first week of February. This year was the coldest, second coldest, and third coldest year, respectively, since 1951 on February 3, 4, and 5. In absolute terms, on the first five days of February, the maximum temperature was 3.2 degrees, 0.5 degrees, 7.7 degrees, 5.4 degrees, and 4.8 degrees below normal. Despite clearer skies compared to January, this temperature was above normal in February only on nine days up to February 20, seven of which were the days from February 13 to 19. The amount by which it has been higher is also not much compared to the amount by which it was below normal in the first week of February. On the nine days of above normal temperatures, the most maximum temperature has deviated is 2.5 degrees. This has made it harder for the average temperature in February 2022 to catch up with the normal.

Rainfall has interrupted any consistent rise in temperature

Maximum temperature has been above normal in Delhi on only 12 days so far this year, seven of which have come in the last week alone. Why did this not happen before this period in February? The reason for that is there were two spells of rainfall before February 15 not only in Delhi, but also in the northwestern states of Punjab, Haryana, Rajasthan, Himachal Pradesh and Uttarakhand, and in neighbouring Uttar Pradesh. These two spells took place between February 3 and 5 and between February 9 and 10. There has also been rainfall in some of these states from February 16, but this was not even 5% of the rainfall in the first half of February in any of the states.

Low temperatures were not just the result of rainfall

Rainfall is not the only reason why temperatures have been low in Delhi. Windy conditions when it was not raining could have kept temperatures low. Although not a foolproof measure, the air quality in Delhi is an indication of this. Delhi’s Air Quality Index has been either the best or second best since 2018 on 10 of 20 days this February. Only three of these days have come in the last week, when higher temperatures could have also aided good air quality. Eight of the days occurred when it did not rain in Delhi and three days when it did not rain in any neighbouring states either.