Thunder before Summer: May 2026 Ends Spring on an Unsettled Note
Air Temperature
| Highest Maximum | 29.8°C | 29th |
| Lowest Maximum | 19.6°C | 2nd |
| Highest Minimum | 20.6°C | 30th |
| Lowest Minimum | 9.4°C | 3rd |
| Mean Maximum | 23.5°C |
| Mean Minimum | 16.3°C |
| Mean | 19.9°C |
Relative Humidity
| Highest Relative Humidity | 92% | Numerous days |
| Lowest Relative Humidity | 41% | 31st |
| Mean Relative Humidity | 75.8% |
Wind
| Highest Gust | 49.9km/h | 16th |
| Days with Force 5 (29 – 38kph) | 5 days |
| Days with Force 6 (39 – 49kph) | 5 days |
| Days with Force 7 (50 – 61kph) | 0 days |
| Days with Force 8 (62 – 74kph) | 0 days |
| Days with Force 9 (75 – 88kph) | 0 days |
| Days with Force 10+ (89kph+) | 0 days |
| Mean Wind Speed | 10.5km/h |
| Most Frequent Wind Direction | Northwest |
Atmospheric Pressure
| Highest Atmospheric Pressure | 1025.8hPa | 25th |
| Lowest Atmospheric Pressure | 1005.6hPa | 16th |
| Mean Atmospheric Pressure | 1017.1hPa |
Precipitation
| Total Rainfall During May2026 | 9.2 mm |
| Total Rainfall Since Last 01/09 | 545.5 mm |
| Highest 24 Hour Total | 4.6 mm | 16th |
| Rain Days | 4 days |
| Thunderstorm Days | 3 days |
| Hail Days | 0 days |
Rainfall Events
| 08/05/2026 | 0.3 mm | Isolated Light Rain |
| 15/05/2026 | 0.4 mm | Isolated Light Rain; Distant Thunder |
| 16/05/2026 | 4.6 mm | Morning Isolated Thunderstorm |
| 17/05/2026 | 3.9 mm | Morning Isolated Thunderstorm |
May 2026 Compared to the Climate Means
| Climate Mean | May2026 | Anomaly | |
| Mean Maximum Temperature | 23.9°C | 23.5°C | -0.4°C |
| Mean Minimum Temperature | 15.9°C | 16.3°C | +0.4°C |
| Mean Temperature | 19.9°C | 19.9°C | / |
| Mean Relative Humidity | 74.5% | 75.8% | +1.3% |
| Mean Atmospheric Pressure | 1015.9hPa | 1017.1hPa | +1.2hPa |
| Total Rainfall | 15.0 mm | 9.2 mm | -5.8 mm |
| Total Rainfall Since Last 01/09 | 519.8 mm | 545.5 mm | +25.7 mm |
| Total Rain Days | 6 days | 4 days | -2 days |
| Total Thunderstorm Days | 1 day | 3 days | +2 days |
| Total Hail Days | 0 days | 0 days | / |
Thunder before Summer: May 2026 Ends Spring on an Unsettled Note
May 2026 marked the final month of meteorological spring and delivered a fascinating blend of increasingly summer-like conditions punctuated by a burst of late-season thunderstorm activity. While temperatures overall aligned closely with long-term averages, the month was drier than normal and increasingly dominated by stable anticyclonic conditions, offering some of the clearest indications yet that the transition toward summer was underway.
The mean air temperature reached 19.9°C, exactly matching the climatological average. However, this apparent normality masked a subtle contrast between slightly cooler daytime temperatures and milder nights. The mean maximum temperature stood at 23.5°C, 0.4°C below average, while the mean minimum temperature reached 16.3°C, 0.4°C above normal. The warmest day of the month occurred on the 29th when temperatures climbed to 29.8°C, narrowly missing the 30°C mark and providing a brief taste of the summer heat to come. Conversely, the coolest night was recorded on the 3rd, when temperatures fell to 9.4°C, highlighting the lingering influence of springtime air masses during the first part of the month.
Humidity averaged 75.8%, slightly above normal but continuing the gradual downward trend observed since winter. Relative humidity fell as low as 41% on the 31st, reflecting the arrival of increasingly dry and warm air masses toward the end of the month.
Atmospheric pressure averaged 1017.1 hPa, 1.2 hPa above the climatological mean and the highest monthly average recorded so far in 2026. This shift marks a notable departure from the persistently below-average pressure observed during much of the preceding winter and spring, indicating a strengthening influence of anticyclonic conditions across the central Mediterranean. Pressure ranged from 1005.6 hPa on the 16th to 1025.8 hPa on the 25th.
Wind conditions remained relatively subdued. The mean wind speed was 10.5 km/h, while the northwesterly wind became the dominant direction, a classic warm-season signal across the Maltese Islands. Although ten days recorded Force 5 or stronger winds, no Force 7 or stronger events occurred during the month. The highest gust reached 49.9 km/h on the 16th.
Rainfall was scarce, with only 9.2 mm measured during the month – 5.8 mm below average. Just four rain days were recorded, two fewer than normal, reinforcing the increasingly dry character of late spring. Nevertheless, almost all the month’s rainfall occurred during a brief unsettled spell between the 15th and 17th.
Perhaps the most noteworthy aspect of May was the occurrence of three thunderstorm days, two above the climatological average despite the overall lack of rainfall. On the 16th and 17th, isolated thunderstorms developed over or near the islands, producing 4.6 mm and 3.9 mm of rainfall respectively. These storms were driven by localised instability associated with cold air aloft interacting with increasingly warm surface conditions-— a classic late-spring convective setup.
Rainfall distribution was remarkably uniform and generally low across the archipelago. Kerċem recorded 9.2 mm, the highest total among the observing stations, while several localities in Malta received less than 5 mm. The national mean stood at just 5.2 mm, highlighting how limited precipitation was across the islands.
Despite the dry conditions, cumulative rainfall since 1 September reached 545.5 mm, maintaining a healthy 25.7 mm surplus above average by the end of May. The substantial rainfall accumulated earlier in the hydrological year continued to offset the deficits observed during late spring.

Rainfall Totals around the Maltese Islands in May2026 (and since last September 1st):
Kerċem: 9.2 mm (545.5 mm)
Victoria: 8.7 mm (547.3 mm)
Marsalforn: 7.7 mm (494.3 mm)
Xewkija: 5.2 mm (470.3 mm)
Nadur: 7.2 mm (496.1 mm)
Għajnsielem: 6.1 mm (500.9 mm)
Mellieħa: 4.3 mm (367.5 mm)
Buġibba: 2.1 mm (356.9 mm)
Mġarr: 5.2 mm (502.7 mm)
Naxxar: 5.4 mm (427.7 mm)
Mosta: 3.8 mm (392.6 mm)
Dingli: 5.1 mm (544.7 mm)
Pembroke: 5.2 mm (433.9 mm)
Msida: 4.6 mm (456.1 mm)
Sliema: 5.6 mm (449.6 mm)
Valletta: 4.4 mm (406.0 mm)
Fgura: 4.6 mm (462.7 mm)
Żejtun: 4.3 mm (411.3 mm)
Żabbar: 3.8 mm (381.2 mm)
Imqabba: 2.0 mm (546.6 mm)
Siġġiewi: 3.1 mm (535.8 mm)
Żurrieq: 3.7 mm (543.3 mm)
Marsaxlokk: 4.4 mm (379.2 mm)
NATIONAL MEAN: 5.2 mm (461.2 mm)











