A run of hot days will culminate with Adelaide likely to see the hottest October day since 2006. Starting from today, Adelaide is expected to see a four day spell of more than 30 degrees, the first time this has occurred in October in five years. This weekend and Monday, temperatures will reach in the low 30's each day as northerly winds drag a hot air mass over the city. It will be a warm one on Monday evening into early Tuesday morning, the temperature only dropping down to a balmy 20 degrees overnight. The heat will peak on Tuesday, with Adelaide likely to see at least 35 degrees. Last time the city has been this hot during October was in 2006, when the mercury climbed to 38 degrees. Wednesday will start off warm before the winds change direction. Onshore winds will develop during the morning bringing some much needed relief. Despite the cooler change, temperatures will be warmer-than-average for this time of year for the remainder of the week.