Rainfall and temperature in Somalia since 1901: the climate in numbers

Where these numbers come from

The yearly rainfall and temperature figures are from the CRU TS 4.08 dataset of the University of East Anglia's Climatic Research Unit. It builds a grid of the world's climate from weather station records back to 1901. We took Somalia's national averages from the World Bank's Climate Change Knowledge Portal, which publishes CRU data for every country (World Bank Climate Change Knowledge Portal, Somalia; CRU TS, University of East Anglia). The full yearly table is in the data file somalia-rainfall-temperature-1901-2023.csv on this page.

One national number hides a lot. Somalia stretches from the dry north-east to the farming land between the Juba and Shabelle rivers, and rainfall differs widely between them. Weather stations were few before 1960 and after 1991, so early and recent years rest on fewer readings. A year can look normal in total while a whole season fails in one region.

The year in four seasons

Average rain and temperature by month, 1991 to 2020 (World Bank CCKP, CRU TS 4.08 climatology):

• Jiilaal, the dry season (January to March): 3 mm in January, 3 mm in February, 13 mm in March. 25 to 28°C.
• Gu, the main rains (April to June): 56 mm in April, 56 mm in May, 18 mm in June. April is the hottest month, at 28.3°C.
• Xagaa, the second dry season (July to September): 11 to 14 mm a month.
• Deyr, the short rains (October to December): 45 mm in October, 38 mm in November, 11 mm in December. December is the coolest month, at 25.2°C.

The Gu and Deyr months (April to June and October to December) together bring about 80 percent of the year's rain. Farmers and herders plan around them, and the UN and FEWS NET judge each season to forecast hunger (FEWS NET, Somalia).

Rainfall over 120 years

Average yearly rainfall for each 30-year period (same source):

• 1901 to 1930: 273 mm
• 1931 to 1960: 235 mm
• 1961 to 1990: 283 mm
• 1991 to 2020: 278 mm
• 2014 to 2023: 299 mm

Wettest years: 1967 (419 mm), 1968 (406 mm), 1951 (394 mm), 1923 (383 mm), 1961 (372 mm).

Driest years: 1955 (162 mm), 1939 (170 mm), 1949 (172 mm), 1943 (173 mm), 1980 (193 mm).

Recent years: 2017 had 349 mm, 2019 had 327 mm and 2022 had 330 mm. Yet 2022 was a drought year across much of Somalia. Late 2020 to 2022 brought a run of failed rainy seasons across the Horn of Africa; by August 2022 the World Meteorological Organization warned of a fifth failed season in a row (WMO, August 2022). This station-based yearly total does not show it. Somalia has had few working stations since 1991, so recent CRU values are filled in from distant stations. For single seasons and recent droughts, use the ERA5 figures on the Gu and Deyr rains, 1950 to 2023, which show the Gu of 2022 at 44 percent of normal.

Temperature over 120 years

Average yearly temperature for each 30-year period (same source):

• 1901 to 1930: 26.6°C
• 1931 to 1960: 26.8°C
• 1961 to 1990: 26.6°C
• 1991 to 2020: 26.9°C
• 2014 to 2023: 27.1°C

The 2014 to 2023 average was about 0.5°C warmer than 1901 to 1930. The warmest recent years were 2015 and 2016 (27.2 and 27.3°C). The single warmest year in the series is 1924 (27.6°C), from a time when very few stations reported. Hot years dry out pasture and crops faster, so the same rain goes less far.

Context

See Internal displacement and Prices and inflation.