🇸🇿Eswatini

Eswatini (formerly Swaziland, 17,363 km²) is a landlocked kingdom in Southern Africa between 26°–27°S, bordered by South Africa (430 km) and Mozambique (105 km), spanning elevations from the Great Usutu River at 21 m to Mount Emlembe at 1,862 m across three distinct climatic zones.

The western Highveld (average 1,200 m elevation) features temperate conditions with annual rainfall between 1,000–2,000 mm concentrated during November–March summer thunderstorms, supporting montane grasslands and commercial forestry; temperatures remain mild year-round, seldom uncomfortably hot.

The central Middleveld (around 700 m elevation) hosts the majority of the population including the commercial hub Manzini, receiving moderate rainfall of 700–900 mm and experiencing warm summers around 32°C in Manzini and cooler winters around 17°C. The eastern Lowveld (around 250 m elevation) presents hot, dry conditions with 500–900 mm annual precipitation and summer temperatures routinely exceeding 40°C, supporting cattle ranching and sugarcane cultivation.

The climate is Köppen Cwa (humid subtropical) in the Highveld and Middleveld, transitioning to BSh (hot semi-arid) in portions of the Lowveld. The country experiences Southern Hemisphere seasons reversed from the Northern Hemisphere, with December marking midsummer and June midwinter, and approximately 80% of annual precipitation falling during the October–March rainy season.

Mbabane (Highveld capital, 1,243 m elevation) averages 13°C in June–August winter and 20°C in November–March summer with reliable rainfall, while Big Bend (Lowveld, 150 m) registers warmer conditions throughout the year. Piggs Peak (northwestern Highveld) experiences the highest rainfall in the kingdom.

The severe January 1984 Cyclone Domoina dropped 906 mm at Piggs Peak, including a severe 615 mm in a single 24-hour period, causing the worst flooding in over 20 years; rivers rose 30 m in hours, the floods destroyed or damaged over 100 bridges, closed the main airport, washed out railways, left 10,000 citrus trees destroyed, caused $54 million in damage, killed 73 people, and left 500 homeless while isolating southeastern regions accessible only by air for days.

The severe 1992 ENSO drought damaged subsistence agriculture across the kingdom. The severe 2015–16 El Niño drought crippled the economy, decreasing sugar and soft drink concentrate production (the country's largest exports), threatening 25% of the population with food and water insecurity, and demonstrating the vulnerability of rain-fed maize cultivation that sustains most rural households.

The 2019–20 drought further strained water resources and agricultural productivity. Recurring droughts driven by El Niño cycles increasingly threaten the 75% of the population dependent on subsistence agriculture on Swazi Nation Land, where low productivity and minimal irrigation infrastructure amplify climate vulnerability. Flash flooding during intense summer thunderstorms periodically overwhelms drainage systems, particularly affecting low-lying areas near river courses.

Our archive covers 1 Eswatini cities with daily ERA5 reanalysis data going back to 1940. The warmest July averages occur in Manzini, around 22.2°C, while Manzini records the coldest January nights near 18.8°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 0.7°C.