London is in for a cloudy and humid Saturday, with a 30 per cent chance of showers late this afternoon and a risk of thunderstorms. Southwest winds will reach 20 km/h, with a high of 24 C and a humidex of 32. Tonight will remain mainly cloudy with a 30 per cent chance of showers and a risk of thunderstorms this evening. The low will be 18 C. Sunday will bring a mix of sun and cloud, with a 30 per cent chance of showers early in the morning and late in the afternoon. Winds will become northwest at 30 km/h in the afternoon, with a high of 26 C and a humidex of 31. Overnight, cloudy periods and a 40 per cent chance of showers are expected, with a low of 10 C.