Sunny weather may not stop Covid spread, warns report

WARM weather is not proven to slow the transmission of Covid-19, a scientific review by Oxford University has found, as it warns that sunshine is no excuse to take risks.

Health officials have repeatedly raised hopes that improvements in weather may reduce the spread of the virus.

But the new analysis says it is impossible to know whether this is the case.

Researchers pointed out that the virus has spread in very warm areas of the globe, such as Ecuador, Brazil and India, as well as in the USA sunshine states of Florida, California and Texas.

The analysis said existing data is limited, and may be skewed by the fact that people are more likely to suffer a range of viruses in the winter, leading to more false positive tests for Covid-19.

The analysis, published in the Environmental and Resource Economics journal, says there are a number of potential problems with the data.

Researchers said that during the first months of the pandemic, testing was insufficient everywhere and, when tests were conducted, the reliability of some tests was questionable.

And the study said the weather itself could be influencing the number of tests carried out and who gets tested.

For example, patients suffering from pre-existing diseases might be more likely to become ill in winter and end up undergoing Covid-19 tests, increasing the number of false positive tests.

Such influences make it impossible to statistically separate this effect from any influence of the weather on the actual spread of the virus, the researchers say.

Anant Jani, study author and Oxford Martin Fellow at the University of Oxford, said: “Although we still don’t know the influence of weather on the spread of Covid-19, we are sure of one thing – the virus has been able to spread everywhere, including in very warm areas of the globe.

“It continues to spread even in warmer states in the US. Good weather is no excuse to take risks with a disease that has already killed hundreds of thousands of people.”

Dr Francois Cohen, study lead author from Oxford’s Smith School of Enterprise and the Environment, said: “The existing data can’t reliably tell us whether warmer weather slows down the spread of Covid-19, as some earlier studies have tried to assess, so we urge both policy-makers and the public to act with caution.”

On Tuesday, a study from King’s College London suggested the virus may be more severe in colder months.