Climate of Malta

The average yearly temperature is around 23 °C (73 °F) during the day and 16 °C (61 °F) at night (one of the warmest temperature averages in Europe). In the coldest month – January – the typical maximum temperature ranges from 12 to 20 °C (54 to 68 °F) during the day and the minimum from 6 to 12 °C (43 to 54 °F) at night. In the warmest month – August – the typical maximum temperature ranges from 28 to 34 °C (82 to 93 °F) during the day and the minimum from 20 to 24 °C (68 to 75 °F) at night.

Generally, April starts with temperatures from 17–22 °C (63–72 °F) during the day and 10–14 °C (50–57 °F) at night. November has temperatures from 17–23 °C (63–73 °F) during the day and 11–18 °C (52–64 °F) at night. However even in the winter months of the year (December, January, February) temperatures sometimes reach 20 °C (68 °F), March is transitional, with warmer temperatures, daily maximums often exceed 20 °C (68 °F) and lows are already in the 2 digits (above 10 °C (50 °F)) since early March. With an average of 19.3 °C (67 °F), Malta has the warmest average temperature in Europe. Amongst all capitals in the continent of Europe, Valletta – the capital of Malta has the warmest winters, with average temperatures of around 16 °C (61 °F) during the day and 10 °C (50 °F) at night in the months of January and February. In March and December average temperatures are around 17 °C (63 °F) during the day and 11 °C (52 °F) at night.^[6] In Malta, large fluctuations in temperature are rare. Malta is one of only a handful of locations in Europe with a USDA hardiness zone of 11a, that is the average absolute minimum temperature recorded each year is between 4.4 to 7.2 °C (39.9 to 45.0 °F).^[7]

Malta enjoys one of the most optimal arrangement of hours of daylight in Europe. Days in winter are not as short as in the northern part of the continent, the average hours of daylight in December, January and February is 10.3 hours^[8] (for comparison: London^[9] or Moscow^[10] or Warsaw^[11] – about 8 hours). The shortest day of the year – 21 December – sunrise is around 7:00 and sunset is around 17:00. The longest day of the year – 21 June – sunrise is around 5:30 and sunset is around 20:30.^[12]

As one might expect from Malta's high daylight hours, Malta enjoys around 3,000 hours of sunshine per year (also one of the highest in Europe), from an average of above 5 hours of sunshine per day in December to an average of above 12 hours of sunshine per day in July.^[14][8] Thus, Malta enjoys about twice the amount of sunshine as cities in the northern half of Europe.^{[citation needed]} For comparison, London has 1,461 hours per year;^[15] however, in winter Malta has much more sunshine. For comparison, London has 37 hours^[15] while Malta has 161 hours of sunshine in December.^[14]

Average annual temperature of sea is 20 °C (68 °F) (the highest annual sea temperature in Europe), from 15–16 °C (59–61 °F) in the period from January to April to 26 °C (79 °F) in August. In the 6 months from June to November, the average sea temperature exceeds 20 °C (68 °F). In May and December – the transition months – the average is around 18 °C (64 °F).

In the second half of April, which is the beginning of the summer/holiday season the average sea temperature is 17 °C (63 °F). The highest sea temperature is 27 °C (81 °F) in the middle-3rd week of August. In late August and early September the temperature drops to 26 °C (79 °F), and in the second half of September it drops to 25 °C (77 °F). Around mid-October it drops to 24 °C (75 °F), and during the last week of October it drops to 23 °C (73 °F). By early November the temperature drops to 22 °C (72 °F) (data of 2010).^[6][17]

Water supply poses a problem on Malta, as the summer is both rainless and the time of greatest water use, and the winter rainfall often falls as heavy showers running off to the sea rather than soaking into the ground. Malta depends on underground reserves of fresh water, drawn through a system of water tunnels such as the Ta' Kandja galleries or the Ta' Bakkja tunnels,^[20] which average about 97 m below surface and extend like the spokes of a wheel. In the galleries in Malta's porous limestone, fresh water lies in a lens upon brine. More than half the potable water of Malta is produced by desalination, which creates further issues of fossil fuel use and pollution.^[21]

Malta has an average of 90 precipitation days a year, and experiences from a few to a dozen rainy days per month (≥ 1 mm), ranging from 0.5 of a day in July to around 15 in December. The average annual precipitation is around 600 mm, ranging from ≈0.3 mm in July to ≈110 mm in December.^[14]

The annual average relative humidity is high, averaging 76%, ranging from 69% in July (morning: 78% evening: 53%) to 79% in December (morning: 83% evening: 73%).^[23]

Despite the relative stasis of the Maltese climate, historical records present some variations. In the capital city of Valletta, meteorological officials of the time recorded a temperature of 1.2 °C (34.2 °F) on 19 February 1895, which remains a record for the city.^[25]

Regarding the island as a whole, a temperature of −1.7 °C (28.9 °F) was recorded on 1 February 1962, at Ta' Qali airfield, in the centre of the island, which was accompanied by frozen precipitation (hail), though this temperature is not recognised by the Malta Met Office as it was not an official recording station and didn't use worldwide meteorological standard instruments.^[25]

Snow is a very rare phenomenon, there was a snowfall reported in January 1858, March 1877 (light snow without accumulation), February 1895 (snow without accumulation), January 1905 (flurries without accumulation), March 1949 (snow recorded in the interior of the island),^[26] and 31 January 1962,^[25] On 31 December 2014 snow was reported at various locations.^[27] though the Met Office later confirmed this was actually Graupel or soft hail. It is thought that many historical reports of "snowfall" were likely also Graupel. That Winter went on to be one of the coldest and stormiest ever experienced in the Maltese Islands.^[28][29]

The lowest temperature ever recorded at Luqa International Airport was in January 1981, with 1.4 °C (34.5 °F), and the highest temperature was 43.8 °C (110.8 °F)^[30] recorded on 9 August 1999.^[31]

June 2021 recorded a very rare type of heatwave. For 12 straight days lasting from 20 June until 1 July, maximum temperature exceeded the climate average maximum by more than 5.0 °C (41.0 °F) and it was only due to the turning of the month that the heatwave ceased to be classified as a heatwave.^[32] The record maximum temperature was beaten 3 times during that heatwave – on the 24th with 40.2 °C (104.4 °F), the 25th with 41.3 °C (106.3 °F) and on the 30th with 41.5 °C (106.7 °F).^[33]

• Malta 2021 Stratospheric Balloon, upper-atmosphere weather balloon