🇬🇭Ghana

Ghana (4°44′–11°10′N) is a West African country spanning roughly 238,533 km² on the Gulf of Guinea, stretching about 672 km north–south from the Atlantic coast to the Sahel border with Burkina Faso. The terrain is mostly low-lying, with the Akwapim-Togo ranges in the southeast rising to Mount Afadja at 885 m—the highest peak—and the Volta basin dominating the centre around the world's largest reservoir, Lake Volta, formed by the Black and White Volta confluence in the north.

The climate exhibits a clear south-to-north gradient: tropical monsoon (Am) and tropical rainforest (Af) on the wet southwestern coast and Ashanti highlands, transitioning to tropical savanna (Aw) across the central Volta basin and Brong-Ahafo region, and to hotter, drier semi-arid (BSh) tropical savanna in the north approaching the Sahel near Tamale and Bolgatanga.

Accra on the relatively dry coast averages 27°C year-round with only 730 mm of rain falling in two distinct rainy seasons—May to June and September to October—an anomalously low total caused by coastal upwelling and parallel-coast wind alignment. Takoradi-Sekondi on the wetter southwest coast also averages 27°C but receives 1,250 mm annually; Kumasi in the Ashanti rainforest registers 26°C with 1,400 mm in a single-peak rainy season; Tamale in the Northern Region records 27°C with 1,090 mm concentrated in a single wet season from May to September; Bolgatanga in the far north averages 28°C with 980 mm and endures a hot, dry Harmattan-dominated December–February season.

Ghana experiences notable climate extremes including Sahel-belt droughts in 1982–84 that extended southward, recurrent urban flooding in Accra, including the 3 June 2015 flood and fuel-station explosion that killed over 200 people, and ongoing coastal erosion with Keta and Ada Foah losing land at rates exceeding 2 m/year. Harmattan dust storms occur seasonally during the dry months.

Our archive covers 17 Ghanaian cities with daily ERA5 reanalysis data going back to 1940. The warmest July averages occur in Tamale, around 29.5°C, while Tamale records the coldest January nights near 21°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.5°C.