Unusually long June heatwaves

The weather last month was characterised by longer than usual heat waves, the Met Office said yesterday.

A high temperature episode lasted for five days between the 20th and the 24th, with daily maximum temperatures averaging 37°C. Another one lasting four days with even higher temperatures followed soon after.

Records of the past 84 years held by the MIA Meteorological Office show that only June 1982 had a comparable period of hot temperatures. For seven days in a row between June 21 and 27, 1982, the temperature hovered between 35°C and 40°C. This was 10 degrees above the average. This type of heatwave is very rare in Malta in June. Since 1922 there were only four other years when such high temperatures of 35 °C or higher persisted for three days or more.

With a mean monthly temperature of 24.2°C, last month was generally slightly warmer, by half a degree, than the average. However, the first half of June contrasted sharply with the second half. Whereas the former had a mean temperature of 19.7 °C, a sharp rise of almost nine degrees shot the average temperature of the last half of the month to 28.6 °C.

Whereas the first 15 days of June had an average high of 23.8°C, in the other 15 days of the month the average was 34.7 °C.

The highest temperature last month was 38.5 °C recorded on the last day of the month. The highest June temperature ever noted by the Meteorological Office, now forming part of Malta International Airport plc was 40.1°C on June 13, 1997.

The nights in June with an average temperature of 19 °C were very close to what one would expect, the Met Office said. The warmest was the night of June 22/23 with 25.6°C while the coolest was that of June 5/6 when the thermometer dropped to 14°C. However, the coolest June night on record was that of 6/7th in 1975 when the thermometer dipped to12.6°C.

June is usually quite a dry month with an average rainfall of 0.8 mm. However last month a total of 1.4 mm were measured, practically all of which was deposited during a couple of showers around 1 a.m. on June 3. The wettest June on record was in 1962 with 28.2 mm of rainfall. Three years ago, 16.2 mm of rain fell within a couple of hours on June 20.

The wind at Malta International Airport last month was generally on the slack side with an average speed of six knots (6.9 mph or 11 kilometres per hour) and with 96 per cent of the time within the light to moderate speed bracket. The most frequent direction was the northwesterly and the strongest gust was 30 knots (34.5 mph or 55.6 kilometres per hour) from the Northwest on June 1. The strongest gust at the airport since records started there in 1946 was 50 knots (58 mph or 93 kilometres per hour) from the northwest on June 3, 1949.

There was an average of 11 hours and 30 minutes of bright sunshine a day last month, which means a total of 18 hours more sunshine than an average June. The brightest day was June 13 with 13 hours and 24 minutes of sunshine; the dullest was the 11th with just 36 minutes of sunshine on an otherwise cloudy day.

The Met Office said it was again urging the public to heed its UV Index forecasts as these were showing very dangerous levels of 11 or more.

More information is available at www.maltairport.com/weather