Perth and its surrounds have just had its coldest night of the year so far with temperatures plummeting as much as eight degrees below the July average, and there's more cold to come. It dipped to just 2.2 degrees in the city early on Monday morning, five below average and its lowest temperature since September last year. While this is pretty chilly, it should be expected at this time of year. Last July, Perth dipped below two degrees on three days, which is the average number of days for July. So far this July it is yet to happen. Light frost affected areas just inland. Gingin dipped to minus one degree, seven below average. Southern Cross also recorded a minus one-degree minimum. Other locations which had their coldest night for the year were Swanbourne (six degrees), Pearce (one degree) and Geraldton (seven degrees). Monday night and Tuesday morning will be similarly cold across a large area of western and southern WA. Some locations will even be colder with more patches of light frost likely. It will warm up on Wednesday and more so on Thursday as southerly winds turn more northerly.