Excess March rainfall: What it means for COVID-19 outbreak

• Excessive rainfall in March 2020 — accompanied by thunder, hail and lightning — severely damaged crops. The irregular weather patterns come close on the heels of an economic quarantine, itself the fallout of a worldwide pandemic caused by the COVID-19 disease outbreak.
• The country recorded 77 per cent more rain than normal between March 1 and March 19, 2020. There was large excess rainfall  more than 60 per cent than normal recorded in 381 districts, 57 per cent of all districts in India.
• Around 6,50,000 farmers in Uttar Pradesh suffered estimated economic losses up to Rs. 255 crore.
• he distribution of rainfall throughout the country was uneven. UP and Delhi recorded 698 per cent and 621 per cent excess rain respectively. Bihar received nine times the normal rain it usually receives at this time period, while Jharkhand received eight times more in the same period.  
• Almost all districts in these states recorded large excess rainfall. Chhattisgarh similarly received large excess rainfall in 25 of its 27 districts. Jharkhand, Bihar, Punjab, Uttarakhand and Haryana also witnessed large excess rain.
• But States in the North East received next to no rain, with Arunachal Pradesh, Manipur, Mizoram and Tripura recording large deficits of rainfall at 68, 77, 99 and 84 per cent, respectively. Assam and Nagaland were also not far behind, with 48 and 50 per cent deficit rainfall, respectively. Only Meghalaya and Sikkim, known to naturally receive more rainfall, recorded normal rainfall in March till date.
• Goa remained the only state in the country to receive no rainfall. The union territories of Daman and Diu, Dadra and Nagar Haveli and Puducherry did not receive any rain either.
• The southern peninsula received moderately high rain, with Tamil Nadu receiving next to no rain, an 87 per cent deficit.
• Change in weather conditions - The copious amount of rainfall in March also meant cooler than normal temperatures in these regions, delaying the onset of summer. An extended winter season in 2019 had meant a sudden jump from cold to extremely warm temperatures. 
• These weather conditions hold significance amid the ongoing COVID-19 pandemic. If the virus thrives in cooler temperatures, the districts that received large excess rain provide decent conditions for the virus to spread.
• But some research papers suggested high humidity and temperatures slow the spread of the virus, though these papers were not peer reviewed.
• Scientists warned that the virus spread faster in countries lying in the southern hemisphere, like Australia, set for cooler temperatures in the winter season. But this warning does not come with a detailed study of how weather affects SARS-CoV-2. It is based on the behaviour of other viruses, human behaviour (people mostly huddle together during wintertime) and reduced human immunity to viruses during this period.