Reports

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

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

August 2020 Compared to the Climate Means

Hotter August 2020

August 2020 was the hottest month of the year. It was a staggering 1.4°C hotter than July, the second hottest month of 2020. The average temperature exceeded the climate norm by 1.1°C. The climate average was exceeded on a total of 25 out of 31 days. The maximum temperature for August was registered at the height of a heat spell which characterised much of the second and third week of August. The mercury on the 15^th soared to 35.8°C. Nights offered litle relief throughout. With the exception of just one night (the 21^st), the minimum temperature never dipped below the 23°C mark.

Our weather station in Għarb recorded no precipitation in August 2020, as rain clouds kept well away of the Maltese Islands. It is quite common to experience a completely dry August. In fact, six of the past ten years experienced a bone dry August. An interesting observation was the lack of cumulus clouds (locally referred to as the ‘għarixa’). These were only sparsely observed. This implies a lack of cool air aloft, a sure sign of a stable atmosphere.

Overall, the wind was lighter than normal. The wind gusted up to Force 6 on just three days. All three were back-to-back (the 4^th, 5^th and 6^th). The highest wind gust was registered at 45.1 km/h (Force 6), on the 6^th. These three days were also the only three days with a maximum temperature below 30°C. This was due to a short-lived area of instability across the central Mediterranean.

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

Rainfall Events

July 2020 Compared to the Climate Means

Cooler Days but Warmer Nights in July 2020

At 30.6°C, daytime highs were 0.6°C cooler than normal. Conversely, at 22.9°C, nighttime lows were 0.9°C warmer than the norm. This made for an overall difference of only 0.1°C from the climate mean. Up till 23^rd July, maximum temperatures exceeded the climatic norm of 31.2°C on only three days. This was due to the presence of an upper level cold pool. This covered the central Mediterranean for a large part of the first two thirds of the month. Apart from keeping temperatures cool, this cold pool was responsible for several days with a breezy Northwest wind. The final nine days, on the other hand, were characterised by a heat spell. July 2020’s hottest temperature was recorded at 34.6°C on the 30^th. This was followed by the month’s warmest night. A minimum temperature of 25.8°C was measured just before dawn on the 31^st. Dipping into the sea during this heat spell provided little respite. The sea surface temperature shot up to 28°C, a full 3°C above the climate mean, in the final days of July 2020.

July 2020 is known for being the year’s driest month. This time round, it was a tad different, at least for a few localities. A heavy rain shower produced up to 30.5 mm in localised areas. Rain in July is rare, but not unheard of. This was only the third time in recent decades that such heavy rainfall occurred in July. Meanwhile, our weather station in Għarb only recorded a brief shower, with 0.3 mm of rainfall.

Levels of relative humidity were significantly higher than in a typical July. In fact, all but one morning recorded relative humidity greater than 90%. Most mornings were characterised by mist or fog patches and low clouds. The more humid air can be attributed to the warmer than average sea across the central Mediterranean.

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

June 2020 Compared to the Climate Means

Completely Dry in June 2020

Air temperatures varied between the highest maximum of 33.0°C (on the 30^th) and the lowest minimum of 17.4°C (on the 1^st and 2^nd). Averaging at 27.0°C, the mean maximum temperature was some 0.8°C below the average for this time of year. The minimum temperature, on the other hand, was 0.3°C warmer than the expected value. This made for June being an overall fairly typical one with regards to air temperature. No heatwaves were experienced. In fact, temperatures only exceeded the 30°C mark on 4 days.

Atmospheric pressure was slightly weaker than what one would expect in a typical June. The central Mediterranean was affected by zones of instability more often than usual. This is also reflected in the number of days with winds in excess of 39 km/h (Force 6). This wind speed was reached on a total of 9 days in June 2020. The strongest gust was measured at 59.5 km/h from the Northwest on the 5^th. That day also accounted for the lowest atmospheric pressure reading for June 2020. Most days last month were characterised by a Northwest wind. A more unstable atmosphere also contributed to an overall higher level of relative humidity.

Despite the greater instability, June 2020 ended up being a completely dry month. It was the third completely dry June in the past 10 years. The closest rain showers and thunderstorms were over Sicily.

Air Temperature

Relative Humidity

Atmospheric Pressure

Wind

Precipitation

Rainfall Events

May 2020 Compared to the Climate Means   

One Heatwave and a Severe Thunderstorm in May 2020

Most days last month were characterized by air temperatures at or slightly above the climate average. The same cannot be said for the stretch of days from the 12^th till the 17^th, however. Warmer than average temperatures characterized much of May 2020’s second week. Using the national criterion for a heatwave, we may conclude that the Maltese Islands experienced one heatwave during this month. This lasted for three days, from 14/05/2020 till 16/05/2020. The maximum temperature measured during this heatwave was of 32.3°C on the 16^th. It was the hottest May day in 14 years. With a monthly mean temperature of 21.0°C, May 2020 was 1.4°C warmer than usual. Both days and nights were substantially warmer.

The most notable event last month was a severe thunderstorm on 27/05/2020. At least two thunderstorms drenched mainland Malta on that day. The second of these, which struck late in the afternoon, was confirmed as having been severe. It produced wind gusts of up to Force 8 (over 62 km/h), hailstones with a diameter of around 2.5 centimetres (the size of a €2 coin) and a confirmed waterspout (dissipated when over the beach) close to Armier. Total rainfall ranged from 6.4 mm (Birżebbuġa) to 41.2 mm (Għargħur). A separate shower occurred over parts of Gozo. The western half of the sister island, which encompasses our weather station in Għarb, remained completely dry. Għarb saw only one day of rain. This was the 30^th, when 6.6 mm of rain were measured during an afternoon shower.

This year’s May lived up to the expectation of it being a blustery month, with 10 days in total seeing winds greater than Force 6 (39 km/h) on the Beaufort Scale. Soitherly winds dominated May 2020. In fact, the wind blew from a southerly quadrant on a total of 17 days.

Atmospheric pressure clocked in at an average 1016.9hPa. This is well above average for this time of year.