National capital yesterday recorded a maximum temperature of 40.1 degrees Celsius, the highest temperature in March since 1945.<br />''<br />'' India Meteorological Department (IMD) said, Delhi is under a severe heat wave as maximum temperature is eight degrees above the average for this time of the season. A heat wave is declared if the maximum temperature reaches at least 40 degrees Celsius or more for plains and it is a severe heat wave, if the departure from the average is more than 6.4 degrees Celsius.<br />'' <br />''<span style="color: #222222;">However, the temperature will decrease over the week end and reach 37 degrees by Sunday. The maximum is likely to be 38 degrees Celsius today.</span><br />