Chandigarh, June 9 -- After a mild start to June, thanks to an active western disturbance which brought rain and thunderstorms to the city, summer has turned up its heat on the city as the day temperatures touched 41degC on Monday and is expected to rise further by mid-week. This is the first time this month that the mercury has crossed the 40-degree mark. According to the IndiaMeteorological Department (IMD), temperatures are likely to rise further before a fresh western disturbance hits the city this weekend and brings rain. The highest recorded so far this year was on May 27 when mercury sizzled at 43.1degC. IMD Chandigarh director Surender Paul said, "Currently, warm and dry westerly winds are prevailing in the region. We expect the temperature to go up to 43degC by mid-week and create conditions of heatwave. But a fresh western disturbance is likely to affect the city from Thursday and drag the temperature below 40degC again by Friday." The IMD has issued a yellow alert for heatwave conditions in the city till June 10, asking people to stay updated. An orange alert has also been issued for thunderstorm, lightning and hail for June 11 and June 12. Orange is the second highest of the four-colour warning system used by the IMD, which asks people to remain prepared. A heatwave is declared when the maximum temperature goes 4.5 to 6.4 degrees above normal. The maximum temperature must be over 40degC for this. If it goes over 6.5 degrees above normal, then a severe heatwave is declared. The city previously saw heatwave conditions on May 20 when the maximum temperature rose to 44.4degC, 5.5 degrees above normal. On Monday, the night temperature also rose - from 24.4degC on Sunday to 25.8degC, 0.6 degrees below normal. Over the next three days, the maximum temperature will remain between 40degC and 42degC while the minimum will remain between 27degC and 28degC....