The rain can bring down pollution that is in the air, but that should not make transmission of the virus any faster or slower, I would think.
However, the lockdown situation in your country is a blessing preventing the disease to spread, like it does in other places where (stupid) people travel to a beach to swim, gather for sports, or find an excuse to travel.
Rainfall do not have cleansing effect or slowing down the COVID-19 virus. It is speculated that rain water can dilute or wash away the virus from the surfaces. Rainfall has some dilution and cleansing effect but rainwater is not effective in destroying the virus. Because, when we wash our hands with soap and water it is the soap that breaks down the virus, not water. Hence, it can be said that the virus can not be transmitted by rain.