Thunderstorms and local rainfall are expected until the early evening hours.
As the rain clouds are quite static, the areas affected by rain will be seeing quite some downpour - between 1-3 litres per square metre, the agency warns.
Temperature-wise, the air is cooling off from around 25°C in the afternoon to 19°C in the evening.
Sunshine dominates for the rest of the week, with temperatures between 18-25°C leading up to the weekend bringing dry skies.
