South Australia is set to heat up significantly this week with much of the state on track for its hottest spell since summer and hottest November spell in six years. Temperatures will reach the mid-to-high thirties for three days running north from about Adelaide. The hottest days look like being Tuesday to Thursday when some northern centres will reach the forties. Adelaide can expect its hottest spell since February and hottest November spell since 2009, averaging a maximum of about 35 degrees over the three days. The heat will combine with dry winds to cause fire danger to rise well into the severe and extreme categories across a large area of the state. Thankfully for those not too keen on putting up with temperatures in the mid-to-high thirties, night-time cooling relief will only fail on one night. Adelaide should only cool to the mid twenties on Wednesday night. A cooler change will cross the west and south of the state on Thursday night/Friday morning and the north of the state during Friday. This change will cool the state by 10-to-15 degrees, to about average but bring virtually no rain relief. Apart from parts of the west, the state as a whole is having a drier than average spring. Some areas including the Adelaide Hills, Mt Gambier and Ceduna have gained less than half the average seasonal rainfall.