Four days of heavy dust haze in May

The Malta Airport MetOffice said the weather during May was warmer and windier than the norm, and included four days of heavy dust haze.

This dust in suspension occurred on 16 May in the afternoon, and on the 18 and 19 May in the morning.

The office explained that the Maltese Islands were under the influence of a complex area of low pressure which originated over Algeria and resulted in wide spread dust haze reducing the visibility.

The worst was 16 May at around 2:45pm when the visibility at Malta Airport went down to 1,500m.

A similar phenomenon happened on the afternoon of 22 May when the lowest visibility decreased to 1,200m.

Last month's average air temperature of 20.5°C exceeded the climate norm of 19.1°C by 1.4°C. The highest temperature was registered on 2 May, when it peaked to 28.7°C - 5.4°C more than the 30-year maximum climate norm. The highest temperature ever reached in May was 35.3°C on 23 May 2006.

The lowest temperature last May was 14.4°C and this was recorded on 14 May. The coolest May night was on 4 May 1970 with a low of 8°C.

May 2013 was also much drier than normal, with a total of 1.4mm of rainfall when the 30 year norm is 6.7mm. The lowest amount measured in the month of May is a trace and the last time a trace was measured at the Malta Airport MetOffice in Luqa was in May 2012.

This May no thunderstorm and fog was reported when the norm for May is one day of thunderstorm and one day of fog.

The average sea surface temperature was 18.3°C. This is 0.8°C higher than the average value for May.

The mean relative humidity last month was 67% which is lower than the 30-year mean climate average of 74%.

May 2013 had an average of 10 hours of bright sunshine a day, which is more than the May norm of 9.7 hours. The dullest day was 21 May with 0.8 hours of sunshine while the brightest was 7 May with 12.7 hours. In total we had 309 hours of bright sunshine.

The wind speed in May, averaging 11.2 knots was more than the expected average wind of 9.1 knots of a typical May.

For 48% of the time it was in the light speed bracket (1-10 knots). The Northwest by West was the most frequent direction with 68 hours. On 22 May, a maximum wind gust of 43 knots was recorded from the West by North direction.

The highest wind gust measured at Malta Airport during the month of May since 1947 was 53 knots, recorded on 19 May 1951 and on 6 May 1954.

The Malta Airport MetOffice is now publishing a five-day forecast of heat stress indices online, which evaluates the body stress caused by the combination of the forecast temperature and humidity. More information is available on http://weather.maltairport.com.