It may have been a perfect spring day yesterday, with the temperature nudging 20 degrees Celsius, but you'd be right for thinking that March has been a chilly month on the whole. The Observatory revealed that the 12th of the month was the coldest March day for 17 years. Last Saturday was half a degree cooler than the 9.5 degrees recorded in 1988. The coldest March day on record was the first day of the month in 1986, when the mercury fell to a bitter 4.8 degrees. The Observatory says temperatures will rise to 25 degrees on Tuesday before falling later in the week. But it should stay around the 20-degree mark over the Easter holiday. Hong Kong has issued three cold warnings this month. The March 12 warning came on the latest date in spring since warnings were introduced in 1999. The Observatory blamed the chill on the northeast monsoon. 'The northeast monsoon climate ... hits Hong Kong yearly. It has its own characteristics and it may hit us early in March or later,' Observatory scientific officer Woo Wang-chun said. But he said the cold weather was an isolated case and not the result of climate change. The March average mean temperature in past years was 19.5 degrees, and the average mean low temperature was 16.5 degrees. Up to March 17, however, the average mean temperature was 15.9 degrees and the average mean low temperature was 13.7 degrees. So, will this March break the record? '[We are] approaching the end of March; the northeast monsoon's effects are getting weaker. It will be quite hard for the temperature [to] drop that low again,' Mr Woo said. Today's forecast is for relatively balmy weather, with the temperature reaching 21 degrees. The Observatory predicts cooler weather later in the week with rain patches. The week will begin misty and foggy, with temperatures reaching 25 degrees on Tuesday. A mid-week cold front will bring the temperature down to as low as 16 degrees on Thursday. Meanwhile, the Observatory is open to the public today to celebrate World Meteorological Day. It has also beefed up its 'Dial-a-weather' service - 187 8200 - to offer the latest local and regional weather forecasts.