Accra is the most urbanised city in Ghana and over the last two decades has seen significant changes as a result of rapid population growth and urban sprawl.  

The emergence of new residential areas, industrial zones, and commercial buildings has increased the demand for housing, infrastructure, and roads.

 This expansion has modified the natural environment of the area and led to the formation and warming of Urban Heat Island (UHI).

Studies indicate that urban temperatures in Accra are rising at a faster rate than the surrounding areas, with an average temperature difference of 3-5°C between the city and its surroundings.

 On hot days, the city centre can record temperatures above 34°C, while areas on the outskirts of Accra, such as Dodowa and Nsawam may experience temperatures around 28°C to 30°C.

The land surface temperature (LST) in Accra is often 3°C to 6°C higher than surrounding vegetated areas. Given the rapid urbanization and the ongoing warming trend, further temperature increases are expected in the region.

These changes are anticipated to worsen climate extremes, heighten weather-related health issues, and lead to greater energy consumption, air pollution, and discomfort for residents.

Accra's population has grown by about 50% in the last two decades, adding more heat-producing activities to an already overstressed environment.

The graph below illustrates the steady rise in the city's population over time, reflecting continued urban expansion without significant declines.

The population has increased from 1,815,000 in 2004 to 2,788,000 in 2025, showing a consistent upward trend.

The graph above shows Accra’s population pattern in the past two decades. It illustrates a steady rise in population over time, reflecting continuous urban expansion without any significant declines.

Fig. 1.1

The above table indicates that the population of Accra has been steadily increasing from 1,815,000 in 2004 to 2,788,000 in 2025. Over 21 years, the population grew by 973,000 people, reflecting a significant rise in urbanization.

From 2004 to 2014, the growth rate remained relatively stable, hovering around 2.14% to 2.17%. Between 2015 and 2020, the growth rate showed a gradual decline, reaching a low of 1.48% in 2019. But from 2020 onward, the growth rate has been increasing again, peaking at 2.46% in 2025.

The population growth rate from 2024 to 2025 (2.46%) alone surpasses all previous values making it the highest in the last two decades.

Source: United Nations – World Population Prospects

This increase may be as a result of renewed urbanization possibly due to economic recovery, improvements in infrastructure, or increased migration.

If this trend continues, Accra's infrastructure and services will face even greater demand.

Another factor contributing to the UHI effect in Accra is the reduction of green spaces. Between 2000 and 2020, the city lost approximately 15% of its green spaces, limiting the natural cooling effect that vegetation provides.

Change Detection Map of Accra (2000-2020)

The figure below displays the spatial distribution of built-up areas from 2000 to 2020. The analysis reveals that urban growth was initially concentrated in the central business districts (CBDs) of Osu, Jamestown, and Adabraka, and then expanded towards the peripheries, particularly in areas such as Dansoman, Kaneshie, and La.

This pattern of sprawling urbanization reflects a typical concentric model of urban growth expanding the coverage of the urban heat Island.

Fig.1.2

The figure above displays the classified land-use and land-cover over the last two decades derived from Landsat imagery.

The map displays that Accra has undergone significant land-use transitions over two decades. The decline in vegetation raises concerns about environmental degradation, including loss of biodiversity playing a major contributing factor to the urban heat island effects.

Consequently, population increase, urban sprawl, and the loss of vegetation have all contributed to the rise in temperatures, a defining feature of UHI.

Hourly Temperature Trends in Accra (2024)

Fig.1.3

The figure above shows the hourly temperatures throughout the 12 months of last year. It is evident that temperatures predominantly fall within the hot and sweltering categories. From January to May, daytime temperatures were sweltering.

Even during the rainy season, daytime temperatures remained warm. The sweltering heat returned toward the end of the year, and mornings were often uncomfortable, with warm temperatures.

This trend suggests that afternoons in Accra, regardless of the season, are likely to be either sweltering or, on rare occasions, hot.

This temperature trends shows how Accra’s temperatures stands out from its surroundings, which ultimately results in far-reaching consequences.

Densely populated areas face higher health risks, including heat stress, dehydration, and respiratory issues, with the elderly and young children being most vulnerable.

The rising demand for air conditioning increases energy consumption, further straining the environment as most power comes from non-renewable sources.

Additionally, extreme heat disrupts local ecosystems, destroying fragile habitats and increasing the spread of pests and diseases like mosquitoes, creating a cycle of worsening environmental and health challenges.

Accra's rapid urbanization has drastically transformed its landscape, replacing green spaces with high-rise buildings, concrete roads, and industrial developments.

While this signifies economic growth, it also intensifies the urban heat island (UHI) effect, where urban areas experience significantly higher temperatures due to reduced vegetation and increased impervious surfaces.

To combat this, experts propose solutions such as expanding green spaces, adopting cool roofing and pavement materials, and promoting sustainable urban design.

Additionally, public awareness, policy enforcement, and technological integration, including remote sensing and GIS, can aid in monitoring urban expansion.

Implementing sustainable urban planning, preserving green spaces, mitigating floods, and involving local communities are crucial in ensuring a balanced and environmentally resilient urban future.