A preliminary study by the national meteorological agency Aemet and the Carlos III Health Institute suggests that there is a correlation between temperature, humidity and the spread of coronavirus: the higher the temperature and the humidity, the lower the spread.
Aemet stresses that this study is only in an initial phase and that more detailed analysis will be carried out over the coming weeks in each region of the country.
Data for the preliminary study were gathered for the period 26 March to 5 April. The number of new infections per 100,000 inhabitants was compared with average temperatures. Over that period, the five regions with the highest average temperatures were - in descending order of highest temperatures - the Canaries, the Balearics, Andalusia, Extremadura and Murcia. The incidence of cases, by 5 April, was lowest in four of these five regions; Extremadura was the exception.
This had also been much the same situation on 26 March, when the incidence rates in the Balearics and Valencia were more or less the same. The average temperature in Valencia compared with other regions placed it sixth by 5 April (it had been eighth on 26 March); the incidence rate was not as low as the Balearics by 5 April but was close.
The Aemet-Carlos III Health Institute study is also assessing environmental factors such as air pollution and pollen which could aggravate the disease. A link will be made between environmental, meteorological and health variables in order to improve identification of risk areas in each region and design diagnostic and prevention strategies.