End of Month Reports

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

June 2021 Compared to the Climate Means

June 2021 brings Record-Breaking Temperatures

With a monthly average temperature of 25.8°C, June 2021 was a solid 2.0°C hotter than the climate norm. It was also the third hottest June on record in the Maltese Islands. Only those of 2019 and 2003 were hotter. The average maximum temperature was calculated at 30.2°C, surpassing the average for a normal June by 2.0°C. Nights were also rather warm. The average minimum temperature of 21.4°C exceeded the mean by 1.1°C. Using the national criteria for a heatwave, we can conclude that the Maltese Islands experienced one heatwaves during this month. This heat wave broke records. Lasting from 20^th June through to 30^th June (both days included), it ended up being the longest heatwave experienced locally. The previous record of 10 days was set in August 2017. The heat wave’s final day, 30^th June, broke the record for the hottest June day ever. The temperature at our weather station in Għarb soared to 40.8°C on that day. An even higher value of 41.5°C was recorded at Malta International Airport. One other thing worth noting were the unseasonably cool first half of June. All days up till the 18^th were cooler than average.

The difference in pressure between instability over the western Mediterranean and seasonal high pressure over the Sahara Desert set-up a stream of air from the Sahara Desert towards the western Mediterranean. This helped blow very hot air from the Sahara Desert across the central and southern Mediterranean. This state of affairs resulted in what we know as a heat dome. A heat dome is a weather phenomenon in which high-pressure atmospheric conditions trap air coming in from the Sahara Desert. The trapped air heats up at an alarming rate as it is compressed, like what happens under the lid on a saucepan. In normal conditions, winds are able to move a heat dome around, but because this particular heat dome stretched high into the atmosphere, it wasn’t easy to move about. This led to the persistent heatwave. The heat dome caused air pollution, desert sand and moisture to become stagnant, leading to a choked up atmosphere.

With the exception of an isolated shower on the 2^nd, June 2021 was completely dry across the Maltese Islands. The last time a shower of over 1 mm affected our weather station in Għarb was way back in April.

Levels of relative humidity were also extremely low when compared to the norm. This was due to the relentless intense heat in the second half of the month. Several consecutive days with an average relative humidity in the region of 50% were registered. The driest days were the 25^th and the 28^th, with minimum readings of 18% on both.

Atmospheric pressure was slightly higher than the mean for this time of year, as stronger and more persistent anticyclonic behavior.

r was noted.

Maximum wind gusts reached at least Force 5 on eighteen days last month. The highest wind gust was of 56.3 km/h, on the 26^th.

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

May 2021 Compared to the Climate Means

Completely Dry and Warmer in May 2021

May 2021 was characterized by its warmer than average temperatures. Successive pressure systems of north African origin traversed the central Mediterranean last month, carrying with them warm air masses from over the Sahara Desert. The overall mean temperature of 20.1°C was half a degree warmer than the mean. The warmest day in May 2021 was the 17^th, with a daytime high of 31.0°C being registered on the day. This was the only day with a maximum temperature of 30°C +

No rain was measured over the course of May 2021. This may be down to prevalent ridges of high pressure across the eastern Mediterranean which were sufficient enough to keep rain away from the central Mediterranean. Another probable contributing factor to this was the frequent prescence of layers of warm and dry air aloft. This caused any falling precipitation to re-evaporate before reaching the ground. Evidence supporting this theory was the regular appearance of virga clouds.

May 2021 lived up to its expectation of being a breezy month. In fact, 16 days featured wind speeds of at least Force 5 at times.

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

Rainfall Events

April 2021 Compared to the Climate Means

Almost Completely Dry in April 2021

April 2021 was another month with temperatures around the average. Overall, temperatures were marginally below the mean for the time of year. Days were slightly cooler, while nights were a bit warmer. This was the result of persistent anticyclones over Europe directing colder air from the north towards the central Mediterranean. A brief cool spell towards the start of the month registered April’s lowest temperature readings. With a nighttime low of 8.3°C, the morning of the 9^th was the coolest last month. The warmest day in April 2021 was the 29^th. A daytime high of 25.4°C was registered on the day, as a warm stream of air from the Sahara blew across the central Mediterranean.

An isolated shower on the 5^th brought last month’s only measurable rain. With the exception of a few drops of dusty rain on a few days, April 2021 was otherwise completely dry. Although spring is synonymous with frequent days of grey skies and airborne fine dust, last month did exceed expectation.

With regards to wind, April 2021 featured dominant southerly winds. The most frequent wind direction last month was the East Southeast. Half of the days in April 2021 were characterized by winds blowing from the southern quadrant. April 2021 lived up to its expectation of being a wind-swept month. Gusts of at least Force 6 were recorded on a staggering 16 days, the highest of which was one of 72.4km/h (Force 8), measured on the 16^th. This was during the passage of a north African low. Accompanying most windy days were grey skies and airborne fine dust.

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

Rainfall Events

March 2021 Compared to the Climate Means

Cooler but Drier in March 2021 

March 2021 was the first month in a while to register an overall temperature which was cooler than average. Overall, temperatures were 0.2°C. Whilst maximum temperatures were much cooler than the norm, nighttime lows were marginally warmer. This was due to anticyclones over Europe directing colder air from the north towards the central Mediterranean. The start of astronomical spring was marked by a week-long cold spell that brought temperatures as low as 7.2°C to our shores. The warmest day last month was the 29^th, when a daytime high of 19.7°C was registered. This was unseasonably cool, as March is typically synonymous with the return of 20°C + temperatures locally.

With rainfall amounting to a total of 21.6 mm over the course  of last month, March 2021 was drier than average. Rainfall was just over a half of the climate norm. The rain was spread over 10 days. Although this value incorporates one occurrence of a heavy dewfall, it still is more than the value expected for March. Thunder was heard on two days. Hail was recorded on two days as well.

A number of windy days dotted the month of March. In fact, 10 days last month featured a wind speed of at least Force 6. The highest wind gust last month was measured at 66.0 km/h (Force 6) from the East Southeast. This was early on the 21^st, as a vigorous low pressure system emerged from north Africa and traversed the central Mediterranean. Accompanying this strong wind were dense fog patches and light rain which deposited copious amounts of desert sand.

Several episodes of sea fog were experienced last month. Sea fog forms when a warm and moist air mass from the south is advected over a cooler area of sea. The air mass cools and its temperature falls to the dew point (the temperature at which an air mass becomes saturated and the water vapour in it condenses). As the air slides over the cooler area of sea it becomes increasingly saturated, enhancing the formation of condensation. Normally, sea fog dissipates as it moves inland. However, given that the air on land is very similar to that of the sea at this time of year, the fog persists inland too.

Rainfall Totals around the Maltese Islands in March 2021 (and since last September 1st)

Għarb – 21.6 mm (413.3 mm)

Victoria – 31.5 mm (431.0 mm)

Xewkija – 23.8 mm (347.8 mm)

Nadur – 27.8 mm (486.6 mm)

Mellieħa – 20.2 mm (284.0 mm)

Buġibba – 32.0 mm (343.6 mm)

Mġarr – 17.6 mm (306.7 mm)

Għargħur – 22.8 mm (413.1 mm)

Attard – 36.9 mm (500.2 mm)

Rabat – 27.4 mm (331.0 mm)

Msida – 32.8 mm (449.7 mm)

Valletta – 12.9 mm (266.5 mm)

Luqa – 29.3 mm (443.8 mm)

Żabbar – 37.8 mm (478.0 mm)

Birżebbuġa – 23.4 mm (325.8 mm)

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

Rainfall Events

February 2021 Compared to the Climate Means

February 2021 among the driest ever

Leave for a few days halfway through the month, February 2021 was a very mild one. Overall, temperatures were a staggering 1.5°C above the climate norm. With a maximum temperature of 10.2°C, the 15^th was last month’s coldest day. The air temperature before dawn on the 16^th dipped to a cold 5.9°C, making it the coldest night of February 2021. The vast majority of days last month featured comfortable temperatures, with daytime highs in the region of 17°C and nighttime lows of around 11°C being the most common values. The temperature also shot up to above 20°C on three days (the 5^th, 6^th and 7^th).

Rain over the course of February 2021 was very scarce. In fact, it was among the driest ever. Only 3.4 mm were measured in Għarb. That is just 5% of the climate average. This was spread over three days. The rain was light on all three occasions. Although the situation may not have been as dire in other localities around the Maltese Islands, no area of the nation accumulated more than 10 mm of rain over the course of last month.

The mean reading of atmospheric pressure for February 2021 was of 1021.9hPa. This is much higher than the typical value for this time of year. This was due to an anticyclone that formed halfway through the month and remained stationary over the central Mediterranean till its end. This anticyclone saw readings exceeding 1030hPa on a number of days. The first half of the month was less stable.

The wind reached strengths of Force 7 on 5 days, Force 8 on 1 day and Force 9 on 1 day. All seven windy occurred in the less settled first half of the month. The strongest gust recorded was that of 78.9 km/h. This was on the 7^th. The second half of last month feature a long and uninterrupted run of light winds. The wind blew from southerly quadrants on an astonishing twelve days.

Rainfall Totals around the Maltese Islands in February 2021 (and since last September 1st)

Għarb – 3.4 mm (391.7 mm)

Victoria – 4.6 mm (399.5 mm)

Xewkija – 2.7 mm (324.0 mm)

Nadur – 2.9 mm (458.8 mm)

Mellieħa – 2.0 mm (263.8 mm)

Buġibba – 3.0 mm (311.6 mm)

Mġarr – 1,8 mm (289.1 mm)

Għargħur – 1.3 mm (390.3 mm)

Attard – 3.6 mm (463.3 mm)

Rabat – 3.7 mm (303.6 mm)

Msida – 8.4 mm (416.9 mm)

Valletta – 0.0 mm (253.6 mm)

Luqa – 9.1 mm (414.5 mm)

Żabbar – 9.2 mm (440.2 mm)

Birżebbuġa – 4.1 mm (302.4 mm)

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

Rainfall Events

January 2021 Compared to the Climate Means

January 2021 registers warmest ever January day

January 2021 was an extremely mild one for the Maltese Islands. Overall, temperatures were almost 1.5°C warmer than the climate norm. With a mean minimum temperature of 11.8°C, nights were a staggering 1.9°C warmer than average. For five days, around mid-January, the Maltese Islands experienced what will likely be the coldest part of winter. The nighttime low of 7.9°C, measured on the 19^th, was the coldest for this month. Saturday 9^th January, on the second weekend of 2021, broke Malta’s record for the warmest temperature ever measured in January. A very warm air mass advecting across the central Mediterranean from over the Sahara Desert caused the temperature at our weather station in Għarb to shoot up to 23.6°C. An even warmer value of 25.8°C was measured at the airport in Luqa. That same day was to break the record for the warmest January night ever as well. The minimum air temperature that day dipped to only 17.1°C. The corresponding value at the airport in Luqa was of 19.4°C. This warm temperature was largely due to a dense covering of mid-level cloud which trapped heat beneath.

Rain over the course of Janaury 2021 came in frequent showery episodes and was fairly evenly distributed over the whole month. Despite at least one shower occurring on 18 days (or more than half of all days in January) last month, January 2021 will still go down as having been a drier than average one in terms of total rainfall. The 41.4 mm of rain measured in Għarb over the course of last month was just half of the rainfall normally experienced in a typical January. This situation wasn’t echoed all around the Maltese Islands. In fact, Għarb was the driest around the Maltese Islands. Although most localities still registered below average totals, they fared far better. Rainfall accumulations did exceed the climate norm in some localities. The 92.8 mm of rain garnered in Dingli, made it Malta’s wettest locality for January 2021. Hail was observed on 5 days last month. One of these saw a handful of localities in Malta experience an abundance of this frozen precipitation.

The wind, which blew mainly from a northwesterly direction, reached at least Force 7 on the Beaufort Scale on a total of nine days last month. It reached Force 8 on four of these, with the strongest gust of 66.0 km/h coming during the gale on the 26^th.

The greater incidence of rainy days and an increased frequency in days with strong winds was also reflected in readings of atmospheric pressure. Overall, readings of atmospheric pressure across the central Mediterranean revealed a trend of persistent zones of instability working their way into the region.

Rainfall Totals around the Maltese Islands in January 2021 (and since last September 1st)

Għarb – 41.4 mm (388.3 mm)

Victoria – 67.5 mm (394.9 mm)

Xewkija – 59.5 mm (321.3 mm)

Nadur – 67.7 mm (455.9 mm)

Mellieħa – 50.6 mm (261.8 mm)

Buġibba – 75.3 mm (308.6 mm)

Mġarr – 78.4 mm (287.3 mm)

Għargħur – 86.7 mm (389.0 mm)

Attard – 83.9 mm (459.7 mm)

Rabat – 92.8 mm (299.9 mm)

Msida – 91.8 mm (408.5 mm)

Valletta – 53.4 mm (253.6 mm)

Luqa – 78.8 mm (405.4 mm)

Żabbar – 90.1 mm (431.0 mm)

Birżebbuġa – 61.0 mm (298.3 mm)

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

Rainfall Events

December 2020 Compared to the Climate Means

Warmer December 2020

December’s air temperature peaked on the 5^th, with a daytime high of 20.4°C and a nighttime low of 16.4°C. Conversely, with a daytime high of 13.5°C and a nighttime low of 9.4°C, the 27^th was last month’s coolest day. The 27^th was one of only two days with a minimum temperature below 10°C, as the Maltese Islands missed out on a cold snap that is normally experienced around Christmas. Overall, December 2020 was warmer than normal. The mean temperature of 15.2°C was almost a full degree above the climate mean.

The month of December 2020 maintained the trend set in the second half of November. Rain came in frequent showery episodes and was evenly distributed over the whole month. With a 24 hour total of 20.6 mm, the first day of winter (the 21^st) was the wettest. A total of 94.1 mm of rain was measure in Għarb last month. This value falls just a few millimetres short of the climate average. This puts rainfall in Għarb at 346.9 mm since last September 1^st, a good 20.8 mm higher than the norm. We had rain on 15 days last December. Thunder was heard on 7 of these, whilst hail accompanied the rain on 5 of these.

The month was generally calmer than the norm, maintaining a mean wind speed of 16.0 km/h rather than the expected 18.2 km/h. Whilst windy days were not lacking, the abscence of any extremely strong gales contributed to the lower mean wind speed. The wind reached Force 7 (50km/h) or stronger on 7 occasions. It reached Force 8 (62km/h) on one of these. Winds from the Southwest were characteristic of December 2020. A Southwest wind advects warm and moist air from the south across the central Mediterranean. This attributed to the significantly warmer than average temperatures experienced over the course of last month. It was also the chief cause behind the frequent showery episodes experienced. The persistent availability of warm and moist air around the Maltese Islands helped generate instability whenever cold air aloft reached our region from the north.

Rainfall Totals around the Maltese Islands in December 2020 (and since last September 1st)

Għarb – 94.1 mm (346.9 mm)

Victoria – 82.6 mm (327.4 mm)

Xewkija – 68.0 mm (261.8 mm)

Nadur – 98.4 mm (388.2 mm)

Mellieħa – 56.2 mm (211.2 mm)

Buġibba – 70.0 mm (233.3 mm)

Mġarr – 62.2 mm (208.9 mm)

Għargħur – 56.3 mm (302.3 mm)

Attard – 69.3 mm (375.8 mm)

Rabat – 67.8 mm (207.1 mm)

Msida – 81.6 mm (316.7 mm)

Valletta – 55.8 mm (200.2 mm)

Luqa – 68.2 mm (326.6 mm)

Żabbar – 85.6 mm (340.9 mm)

Birżebbuġa – 51.1 mm (237.3 mm)

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

Rainfall Events

November 2020 Compared to the Climate Means

The Two Faces of November 2020

The first half of November 2020 was characterized by uninterrupted warm temperatures and dry weather. This changed almost like a switch midway through. The second half of last month was dominated by rainy days and cooler temperatures. This abrupt change in meteorological conditions can be attributed to the sudden collapse of an anticyclone which had covered the central Mediterranean for weeks. This allowed cool air from the north to infiltrate our area and clash with the warm and moist air locally to generate successive zones of instability.

Overall, November 2020 turned out to be warmer than the climate norm. At 16.0°C, nights were a solid 1.2°C warmer than normal. Daytime highs on the other hand, with an 20.9°C mean, were only fractionally warmer than the norm. All days up to the 16^th featured warmer than average temperatures. From then on, most days recorded temperatures cooler than the norm. Air temperatures ranged from the coolest of 12.9°C (on the 29^th) to the warmest of 23.6°C (on the 16^th).

It has to be said that a wet second half of the month saved an otherwise bone dry November 2020. All of the 86.6 mm of rain measured in Għarb last month fell during the last two weeks. The rain was spread over 10 days, with the wettest being the 17^th, when 17.9 mm of rain were measured by our rain gauge in Għarb. Thunder was heard on 7 of these. Hail was observed once. Rainfall during the month of November 2020 conformed with the climate norm. This eased the fears of drought created by the lack of rain in October.

A notable observation was the significantly higher than average atmospheric pressure. Mean atmospheric pressure was at a staggering 1021.4hPa. The probable cause of this was the lack of cyclonic activity across the central Mediterranean. Much of the instability was the result of local instability. The stable atmosphere was reflected by the lack of windy days. In fact, the wind reached Force 6 or stronger on just 5 days. It reached Force 7 on just 2 of these. That is a stark contrast from a typical November. November is usually synonymous with the start of gales.

Rainfall Totals around the Maltese Islands in November 2020 (and since last September 1st)

Għarb – 86.6 mm (252.8 mm)

Victoria – 94.7 mm (244.8 mm)

Xewkija – 79.0 mm (193.8 mm)

Nadur – 121.9 mm (289.8 mm)

Mellieħa – 40.6 mm (155.0 mm)

Buġibba – 53.0 mm (163.3 mm)

Mġarr – 57.6 mm (146.7 mm)

Għargħur – 88.0 mm (246.0 mm)

Attard – 72.0 mm (306.5 mm)

Rabat – 54.1 mm (139.3 mm)

Msida – 59.7 mm (235.1 mm)

Valletta – 42.8 mm (144.4 mm)

Luqa – 86.4 mm (258.4 mm)

Żabbar – 79.5 mm (255.3 mm)

Birżebbuġa – 78.9 mm (186.2 mm)

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

October 2020 Compared to the Climate Means

A Marginally Cooler but Significantly Drier October 2020

Overall, October 2020 turned out to be marginally cooler than the climate norm. At 23.7°C, daytime highs were almost a solid 0.8°C cooler than normal. Nights on the other hand, with an 18.5°C mean, were slightly warmer. Last month started off on a very warm note. It was the third October in the past decade to record a maximum temperature of over 30°C. This was on the 3^rd, when the mercury shot up to 31.3°C. The transition to the cool season gained strong momentum during the second half of the month. Successive pockets of cooler air from over Europe meant a good number of days with cooler than average temperatures. A 13.5°C low, the coldest for October 2020, was registered on the 29^th. This was accompanied by rain and strong winds brought about by a sharp cold front.

In a stark contrast to the previous month, October 2020 was very dry. The 32.5 mm of rain accumulated over the course of this month accounted for much less than half of October’s climate average. This was the result of anticyclonic conditions that prevailed over the central Mediterranean. These acted as a barrier, which weakened storms as soon as they reached the Maltese Islands. The 7 days of rain and 3 days of thunder observed last month were less than the norm for this time of year. October is renowned locally for being the stormiest month of the year. This year was different, as no severe rainfall events were experienced.

The average wind speed of 15.3 km/h almost confirmed with the climate mean. Winds from the West Southwest were more dominant. Two near gales (Force 7 winds) swept the Maltese Islands in October 2020, on the 12^th / 13^th and 27^th / 28^th.

Rainfall Totals around the Maltese Islands in October 2020

Għarb – 32.5 mm

Victoria – 26.3 mm

Xewkija – 26.4 mm

Nadur – 44.4 mm

Mellieħa – 33.0 mm

Buġibba – 36.3 mm

Mġarr – 23.1 mm

Għargħur – 51.5 mm

Attard – 61.7 mm

Rabat – 31.4 mm

Msida – 41.0 mm

Valletta – 20.0 mm

Luqa – 28.4 mm

Żabbar – 33.0 mm

Birżebbuġa – 34.0 mm

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

September 2020 Compared to the Climate Means

Hotter September 2020

A hotter than average September brought summer 2020 to an end. With a mean temperature of 25.7°C, September 2020 was 1.1°C warmer than the climate norm. Nights were particularly warm. The mean minimum temperature of 22.9°C exceeded the climate mean by a staggering 1.8°C. Temperatures dropped to below average on only two occasions. These were the 13^th and 14^th, thanks to widespread thunderstorms. A cold front which swept Europe at the end of the month also reached the Maltese Islands. This ensured a cool final five days.

September 2020 produced 133.7 mm of precipitation at our weather station in Għarb. That is just under three times the amount in a typical September. 83% of this fell in just a few hours, during a torrential thunderstorm in the afternoon of the 14^th. There were 8 days of rain in total last month. Thunder was heard on 6 of these. Some hail was observed on 1 of these, the 14^th. Of the 8 rainy days, 6 had a total rainfall of 2.5 mm or less. Statistically, September 2020 was much wetter than normal when compared to the climate average. When you dig into the numbers, however, you’ll see that much of the rain fell in one or two heavy rainfall events halfway through the month.

September 2020 was not as windy. The wind reached Force 7 on only four days. The highest wind gust of 61.2 km/h (from the Northwest) was measured on the 26^th. 17 of 30 days were characterised by a wind speed of Force 2 (light breeze).

Rainfall Totals around the Maltese Islands in September 2020

Għarb – 133.7 mm

Victoria – 123.7 mm

Xewkija – 88.4 mm

Nadur – 123.5 mm

Mellieħa – 79.4 mm

Buġibba – 74.0 mm

Mġarr – 66.0 mm

Għargħur – 106.0 mm

Attard – 172.8 mm

Rabat – 53.8 mm

Msida – 134.4 mm

Valletta – 81.6 mm

Luqa – 143.4 mm

Żabbar – 142.8 mm

Birżebbuġa – 73.0 mm