Climate and Climate Change in Rwanda
Senior 2 · Geography and Environment
Climate and Climate Change in Rwanda
Lesson 1 of 3
22 min
Kigali lies only about 200 km south of the Equator, yet nights there can drop to around 12 °C, and on the summit of Karisimbi there is sometimes frost. Farmers plant in March and September because they know when the rains will come. Understanding Rwanda's climate, and what controls it, explains why tea grows in one place and cattle graze in another, and prepares you to understand how that climate is now changing.
Weather is the condition of the atmosphere at a place over a short time: today's temperature, rain, wind and cloud. Climate is the average weather of a place measured over a long period, usually 30 years or more. "It rained heavily in Huye this afternoon" is weather; "Huye receives most of its rain from March to May and from October to December" is climate.
Rwanda has a tropical highland (temperate tropical) climate: it is cooler than most equatorial places because it is high. In Kigali daily temperatures typically range from about 12 °C to 27 °C, with little change through the year, and annual rainfall is about 1,100 mm. Mountain areas receive more than 1,500 mm. The year has four seasons:
| Season | Months |
|---|---|
| Short dry season | January–February |
| Long rainy season | March–May |
| Long dry season | June–September |
| Short rainy season | October–December |
A town at 1,400 m has a mean temperature of 22 °C. Estimate the mean temperature of a village 1,000 m higher.
Apply it to Karisimbi: if Kigali (about 1,550 m) averages 21 °C, the summit (4,507 m) is 2,957 m higher, so it should be about 2,957 × 0.0065 ≈ 19.2 °C colder, roughly 2 °C. That is why frost can form there.
| Region | Temperature | Rainfall |
|---|---|---|
| High mountains: the Congo–Nile Ridge, the volcanoes, the northern highlands | Coolest; well below 20 °C on average, with cold nights | Wettest; more than 1,500 mm a year in many places |
| Central Plateau | Mild, around 20 °C on average | Moderate, roughly 1,000–1,300 mm |
| Eastern plateaus and lowlands | Warmest | Driest, often under 1,000 mm, with longer dry spells |
| Lake Kivu shores and the Bugarama plain | Warm, especially in the low Bugarama plain | Fairly high, with moisture from the lake |
Tip
Memory hook. "Up 1 km, down 6.5 degrees." For any temperature-and-height question, find the height difference in metres, multiply by 0.0065, then subtract (going up) or add (going down).
Solution: weather is the short-term condition of the atmosphere; climate is the average weather over a long period (30 years or more).
Solution: the belt of rising, rainy air near the Equator follows the overhead sun and passes over Rwanda twice a year.
Solution: difference 1,000 m, so 6.5 °C colder: 21 − 6.5 = 14.5 °C.
Solution: going down 1,500 m: 1,500 × 0.0065 = 9.75 °C warmer, so 10 + 9.75 = 19.75 °C (about 20 °C).
Solution: the east: it is lower, far from the western highlands that force air to rise, so it receives less relief rain.
Summary
Sources and credits
The climatic-regions table (approximate values), worked examples and practice items are written by Ganzaa.
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
