This man predicted a COVID Surge on Feb 17th

This man predicted a COVID Surge on Feb 17th

The COVID surge can be explained by changing weather patterns that forces more people to stay indoors by @MohalJoshi, Feb 17th, 2021

After peaking out at 97k+ new cases per day in middle of Sep 2020, India for the past few weeks has been trending consistently lower for the past few months and has been averaging ~9-12k new cases in past few weeks. (~ 90% reduction in cases)


It is early days yet but it seems that India has bottomed out in terms of new cases and is unfortunately again on the way up. (see image below with 90 day view)


Now with high existing seroprevalence (>50% as per some studies) and the start of vaccination drive it seems unlikely that India again reaches to around 97k new cases every day.

COVID Surges related to weather?

Based on my anecdotal observations it seems that the spread of COVID-19 in several parts of the world seem to be co-related to weather conditions.But this correlation is not in the traditional sense of how we were thinking about flu viruses pre pandemic (i.e. cold weather leads more spread of virus and hot weather leads to slower spread of the virus).

However we know that the traditional theory does not hold true for a place like India where the spread accelerated during the summer months.

The virus seems to spreading faster as per my observations when weather is not conducive for outdoor activities + ventilation of indoor spaces. This could extreme cold weather or hot weather or even rain!

When weather is bad outside people tend to congregate indoors which as well all know is more riskier to spread of disease.

Add to this the bad weather means that one can’t open doors and windows in indoor spaces to better ventilate indoor spaces means that the virus particles linger in these confined spaces longer leading to more probability of infections.

For e.g. New York had a huge surge in cases during March and April and then again in October till today. However it was doing very well from May to September in between. Why? Because the weather was much better during the summer months.

California (which did very well in March & April when NY was doing terrible but did very poorly subsequently during the summer months. During the hot summer months people moved indoors with A.C. on CA (and many states in the West/South) did poorly while NY better at the same time

Coming to India the cases went sort of parabolic first during the harsh summer months and then continued to go up even during the monsoon when people stayed indoors largely.

Post mid September when monsoon abated and the weather improved people could move more outdoors plus more opportunities to better ventilate indoor spaces in nicer weather meant that cases started going down again.

The outside weather theory also seemed to have held true for events like smog/pollution affecting Delhi and Haryana. While many other states reduced post September peak, Delhi had a higher peak in Oct/Nov while Haryana experienced a double top. (as seen below)


Kerala which also experiences a 2nd spell of rain from October onwards is seeing another surge in cases (see image below) during its 2nd rainy season.


Now as it starts getting warmer across India one can expect cases to go up (while in USA as the weather starts to improve cases are going down)

This should increase the urgency on part of government to further speed up vaccinations to prevent any significant rise in new cases over the coming summer/monsoon months in India.