A total of 10.6 mm of rainfall was registered last month, which was higher than the climate norm of 6.7 mm for the month of May, the MIA Met Office said today.
The highest amount of rainfall ever recorded for the month of May occurred in 1976 with a total of 49.1 mm.
Last month, thunderstorms were heard on three occasions (2nd, 21st and 22nd ), compared to the average of four days for the month of May since 1951.
May had a mean temperature of 18.9°C, which made it slightly cooler than Malta's 30-year climate mean of 19.1°C. A higher average temperature was not reached due to a phase of lower than average temperature registered especially during the first 12 days of the month.
The warmest day last month was the 28th when the thermometer at the Met Office's official sites reached 27.3°C.
The warmest May days ever recorded were in 2006 when 35.3°C was reached on the 23rd.
The lowest temperature recorded at Luqa airport last month was 11.1°C recorded on the 8th. The coolest May night since 1923 was that of the 4th of May 1970 with a low of 8°C.
The wind speed last May, averaging 8.9 knots (16.5 kilometres per hour), was 0.1 knots higher than the average speed for May since 1947. For 63 % of the time it was in the light speed bracket.
The West-North-West was the most frequent direction and the strongest gust last month, recorded on the 16th, reached 34 knots (63 kilometres per hour) from the North West. The strongest gust ever measured at the airport in May was 53 knots (98 kilometres per hour) and this was on two occasions - 1951 and 1954.
The average sea surface temperature last month was 18.5°C. This is 1°C warmer than the average value for May since 1978.May was sunnier than 30-year climatological norm for the month - we had an average of 9 hours and 54 minutes of sunshine a day, which means a total of 13 minutes more sunshine than an average May.
The brightest day was the 17th with almost 13 hours, whilst the dullest was the 23rd with only 12 minutes of bright sunshine in an otherwise cloudy day.
The Malta Airport MetOffice is now publishing online a five-day forecast of heat stress indices, which evaluates the body stress caused by the combination of the forecast temperature and humidity.