Calm and mostly sunny weather will remain in Perth before wind and showers dominate conditions from Tuesday to Friday. Perth is coming off the back of its warmest April on record and still has a couple more days of above average temperatures. Today will be mostly sunny and reach 27 degrees before a bit more cloud arrives on Monday with a top of 25 degrees. Both days will be relatively calm due to a high pressure ridge. On Tuesday conditions will gradually deteriorate with an approaching front and trough. Cloud will increase, a few showers will develop, wind will become strong and there is even a low chance of thunderstorms in the area. The front will arrive during the evening, bringing a band of rain and fresh westerly winds. A low pressure system will sit to the south of Western Australia on Wednesday, driving strong westerly winds and showers into Perth. The mercury will remain below 20 degrees for most or all of the day, reminding people of the approaching winter. Thursday and Friday should be similar as the low flings two fronts across southwestern WA. Fresh-to-strong wind and occasional showers will be the main features, with the chance of a storm on Thursday. Easing and then clearing should occur on Saturday due to the development of a high pressure ridge, however the warm temperatures currently in the western capital should stay away until the middle of the following week.