Published 02 September 2026 | Nature & Environment

TL;DR: Sea temperatures off Carboneras reached nearly 30C this summer, adding heat and humidity to the atmosphere and increasing concern about more intense autumn storms and danas.

Nearly 30C sea off Carboneras

The Mediterranean off the Almeria coast has reached exceptionally high temperatures this summer, with readings close to 30C recorded by monitoring buoys near Carboneras. Scientists and meteorologists say the warming sea is not only making coastal conditions less comfortable, but also providing more moisture for severe storms later in the year.

The figures come from the SeaWatch sensors operated by Puertos del Estado. On 22 July, a buoy located off Carboneras recorded 29.93C, the highest reading in its series. A similarly high temperature was measured on 14 August, when the water reached 29.84C.

Nearly 30 degrees offshore

The unusually warm conditions have also affected overnight temperatures. During the early hours of 3 August, the sea temperature fell only to 27.88C, the second-highest minimum in the series. The record remains 28.67C, recorded in August 2023.

For comparison, the highest minimum recorded in 2017 was 23.4C. That year also marked the lowest figure in the series, highlighting how much the measurements have changed across different summers.

Jorge Olcina, professor and head of the Climatology Laboratory at the University of Alicante, described the current situation as highly concerning. He said the upper layer of the sea had remained close to 30C through much of August, at levels not previously seen for such a sustained period.

Carlos Santos, a spokesman for the Agencia Estatal de Meteorologia (Aemet), added that the buoys measure water at a depth of three metres and several miles from the shoreline. The water in swimming areas may therefore be warmer still.

Almeria above normal

Across the Mediterranean, sea temperatures this year are between two and three degrees above the usual level. Along the Almeria coast, the difference from the historical records is between 1.4 and 1.6 degrees.

Those records date back to around 1980, according to Santos. While holidaymakers mainly notice the warmer water as a matter of comfort, the wider consequences are more significant. A hotter sea releases more moisture into the atmosphere, contributing to heavier, stickier conditions along the coast.

Olcina linked the warming water to the growing number of tropical nights, when temperatures remain above 25C. Since 2022, he said, summers have become increasingly uncomfortable in coastal areas because the heat stored in the sea prevents temperatures from dropping sufficiently overnight.

More moisture for storms

The additional humidity also acts as fuel for storm development. According to Aemet data cited by Santos, every extra degree in Mediterranean sea temperature produces a 7% increase in the moisture available in the atmosphere.

This is a cumulative effect. Aemet estimates that atmospheric moisture has increased by between 30% and 40% since the 1980s. That does not mean every storm will be severe, but it increases the amount of energy and water available when the right weather conditions come together.

Higher sea temperatures can contribute to increased rainfall, while storms may also become more intense in terms of lightning, sudden downdraughts and strong wind gusts. Meteorologists are also observing storms that cover larger areas and occur more frequently.

Autumn DANA concern

The change is particularly relevant as the region moves towards the autumn period, when episodes of intense rain and unsettled weather can affect the Mediterranean coast. Santos said there are now more danas than the number of “gota fria” episodes seen during the 1980s, and that storm systems are becoming more intense, extensive and frequent.

The experts’ warning is not based on a single warm day or on beachgoers’ impressions. It comes from a sustained pattern in instrumental readings, including both daytime and overnight measurements. With the sea remaining far above its usual temperature, the amount of atmospheric moisture available for future storms is also higher.

For residents and visitors in Almeria, the immediate sign is a warmer sea and less relief at night. The broader concern is that the same heat may help create more powerful autumn weather, particularly when other atmospheric conditions favour the development of danas.

For updates on protected areas, wildlife, beaches, water and environmental issues, explore our latest Nature & Environment coverage.