Satellite data reveal unusual urban heat pattern in Tangier

Satellite observations have revealed an unusual heat pattern in Tangier, with the city’s urban center recording land surface temperatures significantly higher than surrounding areas for much of the year, according to a study published in the journal Urban Science.

The study examined land surface temperatures in Tangier, Taza, Beni Mellal, Ifrane and Laayoune between 1995 and 2024.

Researchers combined satellite imagery with climate, vegetation and built-up area data to examine how temperatures changed from each city center toward surrounding areas.

Tangier recorded the largest difference among the five cities, with the city center averaging about 4.6 degrees Celsius warmer than surrounding areas.

The researchers found that Tangier’s center remained warmer during much of the year, with the strongest differences occurring in spring, particularly in April and May.

Only about 3% of observations showed the opposite pattern, with the city center recording lower temperatures than surrounding areas.

Researchers attributed the pattern in part to Tangier’s dense built-up environment. Roads, rooftops and other urban surfaces absorb and retain heat differently from vegetation and less-developed land, contributing to higher surface temperatures in heavily developed areas.

The city’s proximity to the sea, surrounding terrain and vegetation also influence how heat is absorbed and released across the urban area.

The other cities examined showed different patterns.

In Taza and Beni Mellal, the contrast between urban centers and surrounding areas varied more significantly by season. Ifrane showed the strongest differences in the opposite direction at certain times, while Laayoune’s dry surroundings contributed to higher surface temperatures outside the urban center.

Bare land in arid areas can heat rapidly under strong sunlight and, in some circumstances, become hotter at the surface than built-up parts of a city. This helps explain why some of the cities studied recorded higher temperatures outside their urban centers.

For the analysis, researchers measured temperatures from the middle of each city outward to a distance of 7 kilometers in different directions, allowing them to compare built-up neighborhoods with surrounding land.

The study measured land surface temperature, rather than air temperature. The satellite observations therefore reflect the temperature of surfaces such as asphalt, rooftops, soil and vegetation, rather than the air temperature measured by conventional weather stations.

The findings highlight differences in how urban form, vegetation, surrounding land and local geography influence surface temperatures across Moroccan cities.