After a scorching weekend, Perth is continuing to swelter through blistering heat with no reprieve expected until later in the week. Both Saturday and Sunday saw the mercury climb to the high 30s in WA's capital, driving locals to the beach in search of relief. The city then had its hottest night so far this month, remaining warmer than 22 degrees. The working week has kicked off with another scorcher. It reached 34 degrees just before 11am, with the mercury forecast to continue climbing to 41 degrees in the afternoon. The cause of the heat is a low pressure trough, which is combining with a high over southern Australia to bring hot and dry northeasterly winds. This trough brings just a slight chance of a thunderstorm this afternoon, which would only bring brief respite from the heat. Overnight a minimum of 26 degrees is expected, which would make it the hottest February night in three years. It should then reach at least 40 degrees on both Tuesday and Wednesday. The last time Perth had three days over 40 degrees was in January 2010, while for February this would be the longest since 1962. Late on Wednesday a trough should sweep across the state's southwest bringing a cool change, with Thursday only expected to reach 29 degrees. It should then warm up again on Friday, although to a more tolerable top in the low-to-mid 30s.