May weather in Malta: warmer afternoons and one rain day that changed the total

May was warmer, but it had not promised a dry contract

May in Malta invites the first proper negotiations about whether the jacket is still necessary. In the 2025 archive the temperature level did move clearly above April, while the most noticeable rain arrived in a short, concentrated interruption. It was a month with a warm spring background and one particularly persuasive reason to retain a flexible plan.

The available complete Mosta days averaged 20.2°C. The average daily high was 23.0°C and the average daily low 17.8°C. Those values describe a different outdoor rhythm from the cooler opening of April, with more warmth across the day rather than only during one unusual afternoon.

This review covers 29 complete days out of May’s 31, and there is no May 2024 series in the saved archive. The missing dates remain blank in the charts. Within the dates we do have, the temperature and rain stories are both clear enough to give May a character of its own.

Warm afternoons without a 30-degree takeover

The highest hourly temperature in the Mosta series was 27.0°C on May 20. The lowest was 15.4°C before dawn on May 3. None of the covered days reached 30°C at this point, even though the daytime values had moved well above those in April.

That distinction is useful. A month can feel warmer and more suitable for a slower outdoor schedule without belonging in the same category as midsummer. The average daily high of 23.0°C gives a more balanced reference than the single 27.0°C peak, especially if you are comparing several possible weeks.

Overnight temperatures also deserve attention. An average daily low of 17.8°C offers a different evening background from April’s 14.1°C, but it does not turn every late hour into the warmest afternoon. The sensible clothing decision is still adjustable. Your bag may carry the light layer for part of the day; that is usually a more pleasant job than wishing it had been packed.

A fairly consistent warm level across the available weeks

The opening ten days averaged about 20.1°C in the Mosta archive. The available middle section averaged 20.0°C, while the closing part averaged 20.4°C. Those small differences suggest that May’s general warmth was established fairly early rather than appearing only in the final few days.

The daily line still contains variation, including the warmest hourly peak on May 20. But the broader mean did not make the sort of sharp climb seen between the beginning and end of June 2025. May’s story is more about a higher seasonal level than a continuous acceleration.

That makes it a useful counterpoint to a simple “later must be warmer” booking rule. Later May had a slightly higher mean in these files, yet the differences between individual dates still matter more for a specific outing. Choose the day’s order using its forecast, particularly when rain or wind appears near the hours you plan to be outside.

May 15 and May 20: a useful five-day contrast

May 15 produced the largest complete daily rain amount, 24.0 mm. May 16 then had the month’s highest hourly wind speed, 12.2 m/s. Four days after that, May 20 supplied the highest hourly temperature, 27.0°C. It is an unusually concise sequence of three different reasons to look beyond the monthly mean.

The warmest date was not the only date worth remembering. A spring month’s character can be shaped just as strongly by the interval that required an itinerary change. Looking at May 15 beside May 20 helps explain how an overall warm month can still include a substantial weather interruption.

The linked dates below are starting points for exploring the hourly forecasts. They also offer a better way to compare memories of a visit: start with the actual date and time, then look at the surrounding pattern. “It rained in May” and “we had warm afternoons in May” do not have to be competing accounts.

One date supplied about 85% of the covered-days rain

The Mosta rain subtotal for the 29 fully covered days was 28.2 mm. Four of those dates reached at least 1 mm. May 15’s 24.0 mm accounted for about 85% of that subtotal, leaving relatively little rain spread across the other available days.

This is precisely the kind of distribution a monthly total cannot explain by itself. The same amount could, in principle, be spread through many small interruptions. Here, the archive placed most of it on one date. The daily rainfall bars make that concentration visible immediately.

For a future May visit, it is a reason to keep a weather check in the plan rather than assume spring has signed a permanent dry-weather agreement. It is also a reason not to let one wet episode define the whole month. A well-chosen indoor alternative can accommodate a short unsettled spell while leaving the warmer outdoor windows available for the things you actually came to see.

A quieter average than April, with a stronger spell still present

Average hourly wind speed at Mosta was 5.7 m/s, slightly below April’s 6.0 m/s. Three covered dates reached at least Beaufort force 6. The highest hourly value, 12.2 m/s on May 16, also falls in force 6.

That is a noticeably smaller count of stronger-wind dates than April’s eleven, although the coverage differs by one day. For this year’s archive, May’s background therefore looked less wind-dominated. The remaining stronger spell still matters if it overlaps a particular boat trip or exposed route.

Direction and timing remain essential companions to speed. A breeze that is welcome during a warm walk can make a particular landing or exposed stretch less attractive. Check the current sea forecast for marine plans, and keep the return hours in view. A lower monthly wind average is useful context, not an instruction to ignore the hourly forecast once you reach the water.

May made a large step up from April

The covered-days mean rose from April’s 16.3°C to May’s 20.2°C at Mosta, a difference of about 3.9°C. Average daily highs rose from 18.8°C to 23.0°C, while average daily lows moved from 14.1°C to 17.8°C. The warming was present across both ends of the daily range.

June then raised the mean again, to 25.1°C. Seen in that sequence, May occupied a distinct middle ground: warmer than April, but still well below June’s overall temperature level. This helps explain why spring and early summer can produce different kinds of outdoor day even when both are described as sunny.

The other available points followed the warm spring picture. Sliema averaged 20.4°C, Marsaxlokk and Comino about 20.7°C, and Victoria 19.6°C. Those values are useful alongside their coverage counts, but a few tenths of a degree should not outweigh the local wind and exposure you find on the day.

The useful May plan is still an adaptable one

A spring visit can make good use of a longer outdoor itinerary, with a sheltered stop built into the route. Check the daytime high and the cooler hours separately if the plan begins early or continues after dinner. The archive’s warmer means support a change of pace from April without making every hour identical.

For the sea, treat the air temperature as one part of the decision. Water temperature, wind, waves and local conditions require their own attention. The marine and Comino stories in the sidebar explore those differences in more detail, particularly the gap between a warm island afternoon and the conditions experienced during a crossing.

May 2025’s standout lesson is that a concentrated rain episode can coexist with a broadly warm month. Most of the available dates had much smaller rain amounts, while the temperature profile stayed around a fairly consistent spring level. Plan for the range, enjoy the suitable windows and let the forecast help choose the order. The jacket debate can remain a minor subplot.

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