Sierra Leone Climate – July 2026 Update
Top 5 Cities: Freetown, Bo, Kenema, Koidu, and Makeni
Temperature, rainfall and emissions data for Sierra Leone
A fresh climate update for Sierra Leone is being generated…
The new monthly summary is being written by Gemini in the background. This usually takes 5–10 seconds. The live climate data below is already up to date.
At a Glance
Temperature – Average
Climate Map – Global
Source: NOAA Climate at a Glance (countries & continents) · Met Office (UK) · US states & climate regions. Anomalies are vs the 1961–1990 baseline. See methodology.
Typical Climate – Sierra Leone
Köppen Aw · TropicalSierra Leone has a tropical climate (Köppen Aw: Tropical savanna (dry winter)), with only modest temperature variation through the year, but a pronounced wet and dry season. March is typically the warmest month, averaging 28.7°C, while August is the coldest at 24.4°C. Annual precipitation averages around 2200mm, concentrated mostly in the wet season.
Monthly climate normals (2016–2025) - bar colour and height show average temperature, the shaded area shows average monthly precipitation.
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Long-Term Trends
Combined Timeline – Sierra Leone
Right axis: everything else standardized to standard deviations (σ) from its own average, since mm/hours/days aren't directly comparable to °C or to each other.
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Heatwave Days – Sierra Leone
Warm Spell Duration Index (WSDI) - the WMO/ETCCDI heatwave measure: days in a 6+ day run above the local 90th-percentile temperature for that time of year.
Data: World Bank Climate Change Knowledge Portal (ERA5-derived). Refreshed roughly 1-2x/year, ~7-8 months behind present.
Year-on-Year Trends
The 4byo Climate Helix – Sierra Leone
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Monthly Temperature – Sierra Leone
Background lines show the last 40 years (plus the record year and its opposite, wherever they fall).
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Records – Sierra Leone
Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP) - Anomalies vs 1901-2000 mean
Shifting Seasons
Wet / dry seasonsKöppen Am · TropicalSierra Leone doesn't have a warm/cold cycle - its monthly temperature range is only 4.0°C across the year - but it does have a strong wet/dry cycle (the wettest month gets 60× as much rain as the driest). So we track how the wet season has shifted instead.
Monthly precipitation climatology. A “wet month” exceeds the baseline monthly mean (dashed gold line). Biggest month-to-month shift: Sep (-245 mm, -42%).
Data: Our World in Data / NOAA (precipitation: GPCC (DWD); frost: World Bank CCKP).
Emissions & Energy
Explore
Explore Climate Data
Data Sources
Data Sources for Sierra Leone
Every figure on this page is sourced from official, openly published climate datasets. Anomalies are calculated against the 1961–1990 baseline (temperature) and 1991–2020 (rainfall, sunshine, frost) - see the Methodology & Sources page for the complete dataset list and update calendar.
Country-level temperature anomaly, sourced from Copernicus ERA5 and Hadley HadCRUT5.
Annual country and global CO₂ emissions, from the Global Carbon Project.
Monthly rainfall - Global Precipitation Climatology Centre (DWD) preferred, World Bank CCKP/CRU TS fallback where GPCC lacks direct coverage.
Frost Days and Heatwave Days (Warm Spell Duration Index), ERA5-derived. World Bank Climate Change Knowledge Portal.
Monthly snow water-equivalent, Global Precipitation Climatology Centre (DWD).
FAQs
FAQs
How is the climate in Sierra Leone changing?
Sierra Leone is warming in line with the rest of the world. The page above shows the latest monthly temperature anomaly versus the 1961-1990 baseline, the long-term annual trend, and the region's rank in the historical record. The headline panel also shows the long-term trend rate per decade and the warmest and coolest years on file.
What is the climate like in Sierra Leone?
Sierra Leone has a tropical climate (Köppen Aw: Tropical savanna (dry winter)), with only modest temperature variation through the year, but a pronounced wet and dry season. March is typically the warmest month, averaging 28.7°C, while August is the coldest at 24.4°C. Annual precipitation averages around 2200mm, concentrated mostly in the wet season.
Where does the climate data for Sierra Leone come from?
Climate data for Sierra Leone comes from Our World in Data, sourcing Copernicus ERA5 and HadCRUT5 (national temperature anomaly) and the Global Carbon Project via Our World in Data (CO₂ emissions), refreshed every month, when the upstream temperature and rainfall data are refreshed.
What is the climate baseline used on this page?
Anomalies on this page are calculated against the 1961-1990 climatological baseline, which is the standard reference period used by the Met Office, NOAA, IPCC and most national climate services. Some panels also show the source-native 1901-2000 (NOAA) or 1991-2020 (WMO) baselines for verification. See Methodology & Sources for the full reference.
Which areas does the Sierra Leone climate data cover?
The Sierra Leone climate profile covers Freetown, Bo, Kenema, Koidu and surrounding areas. Temperature, rainfall and emissions data for Sierra Leone
How often is the Sierra Leone climate update refreshed?
The Sierra Leone climate update is refreshed monthly, typically a few days after the previous month closes and the upstream provider (Met Office HadUK-Grid, NOAA Climate at a Glance, Copernicus ERA5 or the Global Carbon Project) publishes its update. See the Climate Rankings for cross-region comparisons.
What counts as a Heatwave Day on the Sierra Leone climate page?
Heatwave Days use the Warm Spell Duration Index (WSDI) - the WMO/ETCCDI-standard heatwave measure: days that are part of a run of 6 or more consecutive days above the local 90th-percentile temperature for that calendar day. The 90th-percentile threshold varies by time of year (a hot day in January is judged differently to one in July) but is fixed to the 1961-1990 baseline for every year shown - it does not shift as the climate warms, which is why Heatwave Days trend upward over time.
Does the Sierra Leone climate page include frost and snow data?
Yes. Frost Days (days with a minimum temperature below 0°C, World Bank CCKP) and snow water-equivalent (GPCC) are shown alongside temperature and precipitation, each measured against the 1961-1990 baseline where a like-for-like historical comparison is available.