Climate and average weather in Koidu
In Koidu, the summers are sweltering, dry, and mostly clear and the winters are warm and mostly cloudy.
Over the course of the year, the temperature in Koidu typically varies from 20°C to 34°C, and is rarely below 16°C or above 36°C. February is the hottest month of the year, while August is the coldest.
Based on the travel score, the best times of year to visit Koidu for warm-weather activities are from early January to late January and late November to late December.
- Hottest
- Feb
- 34°
- Coldest
- Aug
- 21°
- Wettest
- Sep
- 422 mm
- Driest
- Jan
- 11 mm
- Rain / yr
- 2439 mm
- 222 wet days
- Daylight
- 11.5–12.5 h
- shortest–longest
- Elevation
- 381 m
- 8.6°N
- Clearest
- Jan
- 36% cloud
Koidu is city in Kono District, Sierra Leone.
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Koidu weather by month, at a glance
The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.
Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around late November to late December.
Temperature through the year
Daily average highs and lows in Koidu, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
Temperatures in Koidu stay fairly even through the year, without a distinct hot or cool season. The warmest month is February, with an average high of 34°C and low of 22°C; the coolest is August, with an average low of 21°C and high of 27°C.
Days typically run about 8°C warmer than nights, with the widest day–night swing (around 12°C) in January.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 32 | 34 | 33 | 32 | 30 | 28 | 27 | 27 | 28 | 29 | 29 | 30 |
| Avg low (°C) | 20 | 22 | 23 | 23 | 23 | 22 | 21 | 21 | 21 | 21 | 21 | 20 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 32 | 20 |
| Feb | 34 | 22 |
| Mar | 33 | 23 |
| Apr | 32 | 23 |
| May | 30 | 23 |
| Jun | 28 | 22 |
| Jul | 27 | 21 |
| Aug | 27 | 21 |
| Sep | 28 | 21 |
| Oct | 29 | 21 |
| Nov | 29 | 21 |
| Dec | 30 | 20 |
How hot and cold Koidu really feels
The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.
On the hottest afternoons, once humidity is folded in, Koidu feels like about 36°C (around March 22). About 143 days a year carry some heat stress, peaking in March.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Feels-like high (°C) | 32 | 34 | 36 | 35 | 33 | 31 | 28 | 27 | 30 | 32 | 32 | 31 |
| Air high (°C) | 32 | 34 | 33 | 32 | 30 | 28 | 27 | 27 | 28 | 29 | 29 | 30 |
| Feels-like low (°C) | 20 | 22 | 23 | 23 | 23 | 22 | 21 | 21 | 21 | 21 | 21 | 20 |
| Air low (°C) | 20 | 22 | 23 | 23 | 23 | 22 | 21 | 21 | 21 | 21 | 21 | 20 |
| Feels-like high (°C) | Air high (°C) | Feels-like low (°C) | Air low (°C) | |
|---|---|---|---|---|
| Jan | 32 | 32 | 20 | 20 |
| Feb | 34 | 34 | 22 | 22 |
| Mar | 36 | 33 | 23 | 23 |
| Apr | 35 | 32 | 23 | 23 |
| May | 33 | 30 | 23 | 23 |
| Jun | 31 | 28 | 22 | 22 |
| Jul | 28 | 27 | 21 | 21 |
| Aug | 27 | 27 | 21 | 21 |
| Sep | 30 | 28 | 21 | 21 |
| Oct | 32 | 29 | 21 | 21 |
| Nov | 32 | 29 | 21 | 21 |
| Dec | 31 | 30 | 20 | 20 |
Average hourly temperature in Koidu
A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on February afternoons, near 34°C, and coldest before dawn in August, near 21°C.
Koidu weather by month
Every month at a glance. Click a month for its detailed page.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 32° / 20° | 11 | 2.4 | 11.6 | 4.9 |
| Feb | 34° / 22° | 14 | 2.9 | 11.7 | 3.8 |
| Mar | 33° / 23° | 63 | 10.3 | 11.9 | 3.4 |
| Apr | 32° / 23° | 105 | 15.7 | 12.2 | 3.5 |
| May | 30° / 23° | 235 | 25.4 | 12.4 | 3.2 |
| Jun | 28° / 22° | 335 | 28 | 12.5 | 3.3 |
| Jul | 27° / 21° | 369 | 29.3 | 12.5 | 3.5 |
| Aug | 27° / 21° | 419 | 29.7 | 12.3 | 3.4 |
| Sep | 28° / 21° | 422 | 28.8 | 12.1 | 3.3 |
| Oct | 29° / 21° | 322 | 29.5 | 11.8 | 3.1 |
| Nov | 29° / 21° | 129 | 16.4 | 11.6 | 4.5 |
| Dec | 30° / 20° | 16 | 3.1 | 11.5 | 5.9 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
Koidu gets about 2439 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.
The wetter season lasts 6.7 months, from around Apr 23 to Nov 11, peaking in August at about 97% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jan 1.
September is the wettest month by volume, with 422 mm over about 29 wet days; January is the driest, with 11 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 8 | 11 | 31 | 54 | 82 | 93 | 95 | 96 | 96 | 94 | 54 | 12 |
| Rain days | 2 | 3 | 10 | 16 | 25 | 28 | 29 | 30 | 29 | 30 | 16 | 3 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 8 | 2 |
| Feb | 11 | 3 |
| Mar | 31 | 10 |
| Apr | 54 | 16 |
| May | 82 | 25 |
| Jun | 93 | 28 |
| Jul | 95 | 29 |
| Aug | 96 | 30 |
| Sep | 96 | 29 |
| Oct | 94 | 30 |
| Nov | 54 | 16 |
| Dec | 12 | 3 |
Monthly rainfall
Over a full year, Koidu collects about 2439 mm of rain across 222 wet days — roughly 203 mm in an average month.
It doesn’t fall evenly. September is the wettest month with 422 mm, while January is the driest at just 11 mm. The three wettest months alone bring about 50% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 11 | 14 | 63 | 105 | 235 | 335 | 369 | 419 | 422 | 322 | 129 | 16 |
| Rain days | 2 | 3 | 10 | 16 | 25 | 28 | 29 | 30 | 29 | 30 | 16 | 3 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 11 | 2 |
| Feb | 14 | 3 |
| Mar | 63 | 10 |
| Apr | 105 | 16 |
| May | 235 | 25 |
| Jun | 335 | 28 |
| Jul | 369 | 29 |
| Aug | 419 | 30 |
| Sep | 422 | 29 |
| Oct | 322 | 30 |
| Nov | 129 | 16 |
| Dec | 16 | 3 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In Koidu, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.
The clearer part of the year begins around November 11 and lasts for 5.1 months, ending around April 15. The clearest month is January, when the sky is clear, mostly clear, or partly cloudy 76% of the time on average.
The cloudier part of the year begins around April 16 and lasts for 6.9 months, ending around November 10. The cloudiest month is August, when it is overcast or mostly cloudy 98% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 76 | 73 | 53 | 30 | 8 | 5 | 2 | 2 | 5 | 14 | 36 | 66 |
| Cloudier (%) | 24 | 27 | 47 | 70 | 92 | 95 | 98 | 98 | 95 | 86 | 64 | 34 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 76 | 24 |
| Feb | 73 | 27 |
| Mar | 53 | 47 |
| Apr | 30 | 70 |
| May | 8 | 92 |
| Jun | 5 | 95 |
| Jul | 2 | 98 |
| Aug | 2 | 98 |
| Sep | 5 | 95 |
| Oct | 14 | 86 |
| Nov | 36 | 64 |
| Dec | 66 | 34 |
Daylight, sunrise and sunset
Hours of daylight through the year, with sunrise and sunset times.
The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around May 28, brings about 12 h 30 min of light; the shortest, around January 1, only 11 h 30 min — a swing of roughly 1 hour.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 11.6 | 11.7 | 11.9 | 12.2 | 12.4 | 12.5 | 12.5 | 12.3 | 12.1 | 11.8 | 11.6 | 11.5 |
| Sunrise (AM) | 7:07 | 7:07 | 6:55 | 6:38 | 6:28 | 6:29 | 6:36 | 6:39 | 6:37 | 6:35 | 6:41 | 6:55 |
| Sunset (PM) | 6:40 | 6:50 | 6:52 | 6:50 | 6:52 | 6:59 | 7:03 | 6:57 | 6:40 | 6:23 | 6:17 | 6:25 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 11.6 | 7:07 | 6:40 |
| Feb | 11.7 | 7:07 | 6:50 |
| Mar | 11.9 | 6:55 | 6:52 |
| Apr | 12.2 | 6:38 | 6:50 |
| May | 12.4 | 6:28 | 6:52 |
| Jun | 12.5 | 6:29 | 6:59 |
| Jul | 12.5 | 6:36 | 7:03 |
| Aug | 12.3 | 6:39 | 6:57 |
| Sep | 12.1 | 6:37 | 6:40 |
| Oct | 11.8 | 6:35 | 6:23 |
| Nov | 11.6 | 6:41 | 6:17 |
| Dec | 11.5 | 6:55 | 6:25 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
Koidu averages about 6 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 19 days.
The sunnier stretch runs 4.2 months, from around Nov 22 to Mar 29. The sunniest month is January, with roughly 18 sunny days (bright).
The greyest month is May, down near 0 sunny days — about 99% fewer than the January peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 18 | 16 | 10 | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 5 | 15 |
| Sky | Bright | Bright | Mixed | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Mixed |
| Sunny days | Sky | |
|---|---|---|
| Jan | 18 | Bright |
| Feb | 16 | Bright |
| Mar | 10 | Mixed |
| Apr | 3 | Gloomy |
| May | 0 | Gloomy |
| Jun | 0 | Gloomy |
| Jul | 0 | Gloomy |
| Aug | 0 | Gloomy |
| Sep | 0 | Gloomy |
| Oct | 0 | Gloomy |
| Nov | 5 | Gloomy |
| Dec | 15 | Mixed |
Humidity comfort
Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.
Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.
In Koidu, how humid it feels changes dramatically over the year.
The more humid part of the year lasts 8.9 months, from around March 13 to December 7. The muggiest month is April, when the air feels humid, muggy or worse about 100% of the time.
The most comfortable stretch runs from around December 8 to March 12, and January is the most comfortable month — the air is dry or comfortable 40% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 25 | 14 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 11 |
| Comfortable (%) | 14 | 14 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 8 |
| Humid (%) | 27 | 28 | 19 | 4 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 14 |
| Muggy (%) | 27 | 32 | 35 | 14 | 2 | 13 | 46 | 46 | 23 | 12 | 21 | 42 |
| Oppressive (%) | 7 | 12 | 40 | 82 | 97 | 87 | 54 | 54 | 77 | 88 | 78 | 26 |
| Miserable (%) | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| Jan | 25 | 14 | 27 | 27 | 7 | 0 |
| Feb | 14 | 14 | 28 | 32 | 12 | 0 |
| Mar | 2 | 5 | 19 | 35 | 40 | 0 |
| Apr | 0 | 0 | 4 | 14 | 82 | 0 |
| May | 0 | 0 | 0 | 2 | 97 | 1 |
| Jun | 0 | 0 | 0 | 13 | 87 | 0 |
| Jul | 0 | 0 | 0 | 46 | 54 | 0 |
| Aug | 0 | 0 | 0 | 46 | 54 | 0 |
| Sep | 0 | 0 | 0 | 23 | 77 | 0 |
| Oct | 0 | 0 | 0 | 12 | 88 | 0 |
| Nov | 0 | 0 | 1 | 21 | 78 | 0 |
| Dec | 11 | 8 | 14 | 42 | 26 | 0 |
Wind
Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.
This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.
Across the year, average wind speed in Koidu is typically calm, near 5 km/h, and varies little with the seasons.
The windier part of the year lasts 3.0 months, from around Jun 15 to Sep 13. The windiest month is August, averaging about 7 km/h (calm).
The calmer part of the year runs from around Sep 14 to Feb 2, with October the calmest month at about 4 km/h.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 5 | 6 | 6 | 6 | 5 | 6 | 7 | 7 | 5 | 4 | 4 | 5 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 5 | calm |
| Feb | 6 | calm |
| Mar | 6 | calm |
| Apr | 6 | calm |
| May | 5 | calm |
| Jun | 6 | calm |
| Jul | 7 | calm |
| Aug | 7 | calm |
| Sep | 5 | calm |
| Oct | 4 | calm |
| Nov | 4 | calm |
| Dec | 5 | calm |
Hazard calendar for Koidu
When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.
Koidu's monsoon runs May–October, when most of the year's rain falls.
Koidu sees seasonal dust haze (February–April), heaviest in April.
Best time to visit Koidu
To characterize how pleasant the weather is in Koidu throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around late December, Koidu is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.
Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.
The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Koidu for general outdoor tourist activities is from mid November to late January, with a peak score in the third week of December.
The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Travel score (0–10) | 4.9 | 3.9 | 3.4 | 3.5 | 3.2 | 3.3 | 3.5 | 3.4 | 3.3 | 3.1 | 4.5 | 5.8 |
| Rating | fair | fair | poor | poor | poor | poor | poor | poor | poor | poor | fair | good |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 4.9 | fair |
| Feb | 3.9 | fair |
| Mar | 3.4 | poor |
| Apr | 3.5 | poor |
| May | 3.2 | poor |
| Jun | 3.3 | poor |
| Jul | 3.5 | poor |
| Aug | 3.4 | poor |
| Sep | 3.3 | poor |
| Oct | 3.1 | poor |
| Nov | 4.5 | fair |
| Dec | 5.8 | good |
The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Koidu for hot-weather activities is from late November to early March, with a peak score in the last week of December.
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
What to pack for Koidu, by month
Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.
For a warm-season trip around February (highs near 34°C), the essentials are light clothes and sun protection. In the cold season around August (highs near 27°C), pack light clothes and rain gear.
In February, Koidu sees daytime highs around 34°C and nights near 22°C. Pack light clothes. Worth having: sun protection.
UV index (midday) in Koidu by month
Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.
Under clear skies, the midday UV index in Koidu peaks around August 22 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 at about 8 (very high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 10 | 12 | 13 | 11 | 12 | 12 | 12 | 13 | 13 | 12 | 9 | 8 |
| Level | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | Very high |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 10 | Very high |
| Feb | 12 | Extreme |
| Mar | 13 | Extreme |
| Apr | 11 | Extreme |
| May | 12 | Extreme |
| Jun | 12 | Extreme |
| Jul | 12 | Extreme |
| Aug | 13 | Extreme |
| Sep | 13 | Extreme |
| Oct | 12 | Extreme |
| Nov | 9 | Very high |
| Dec | 8 | Very high |
Average hourly UV index in Koidu
Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.
The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
UV falls off far faster than brightness as the sun drops, so even in August the burn window is concentrated in the middle of the day: about 8 hours a day reach index 3 (protection recommended), and 6.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV ≥ 3 (h/day) | 7 | 7.5 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 7 | 6.5 |
| UV ≥ 6 (h/day) | 5 | 6 | 6 | 6 | 6 | 6 | 6 | 6.5 | 6 | 6 | 5 | 4 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 7 | 5 |
| Feb | 7.5 | 6 |
| Mar | 8 | 6 |
| Apr | 8 | 6 |
| May | 8 | 6 |
| Jun | 8 | 6 |
| Jul | 8 | 6 |
| Aug | 8 | 6.5 |
| Sep | 8 | 6 |
| Oct | 8 | 6 |
| Nov | 7 | 5 |
| Dec | 6.5 | 4 |
Air quality in Koidu by month
Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.
Air quality in Koidu is worst in March — around 233 µg/m³ PM2.5 (very unhealthy), about 25.9× the cleanest month (August, 9 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 90 | 98 | 233 | 151 | 27 | 18 | 11 | 9 | 10 | 16 | 22 | 45 |
| Level | Unhealthy | Unhealthy | Very unhealthy | Very unhealthy | Moderate | Moderate | Good | Good | Good | Moderate | Moderate | Poor |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 90 | Unhealthy |
| Feb | 98 | Unhealthy |
| Mar | 233 | Very unhealthy |
| Apr | 151 | Very unhealthy |
| May | 27 | Moderate |
| Jun | 18 | Moderate |
| Jul | 11 | Good |
| Aug | 9 | Good |
| Sep | 10 | Good |
| Oct | 16 | Moderate |
| Nov | 22 | Moderate |
| Dec | 45 | Poor |
Growing season
Koidu is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Frost-free chance (%) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Frost nights | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Frost-free chance (%) | Frost nights | |
|---|---|---|
| Jan | 100 | 0 |
| Feb | 100 | 0 |
| Mar | 100 | 0 |
| Apr | 100 | 0 |
| May | 100 | 0 |
| Jun | 100 | 0 |
| Jul | 100 | 0 |
| Aug | 100 | 0 |
| Sep | 100 | 0 |
| Oct | 100 | 0 |
| Nov | 100 | 0 |
| Dec | 100 | 0 |
Growing degree days
Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Koidu banks about 5,693 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around March.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Growing degree days (°C·days) | 494 | 492 | 562 | 518 | 498 | 449 | 437 | 430 | 435 | 464 | 449 | 463 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 494 |
| Feb | 492 |
| Mar | 562 |
| Apr | 518 |
| May | 498 |
| Jun | 449 |
| Jul | 437 |
| Aug | 430 |
| Sep | 435 |
| Oct | 464 |
| Nov | 449 |
| Dec | 463 |
Solar energy
Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.
Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.
Koidu receives about 4.8 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.4 and 6.1 kWh/m².
The brighter stretch of the year lasts 5.3 months, from around Nov 27 to May 5. The brightest month is March, averaging about 5.9 kWh/m² (bright).
The dimmest month is August, down near 3.5 kWh/m² — roughly 42% less than the March peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.6 | 6.0 | 6.0 | 5.4 | 4.6 | 4.1 | 3.7 | 3.5 | 4.1 | 4.7 | 4.7 | 5.2 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Moderate | Moderate | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 5.6 | Bright |
| Feb | 6.0 | Bright |
| Mar | 6.0 | Bright |
| Apr | 5.4 | Bright |
| May | 4.6 | Bright |
| Jun | 4.1 | Bright |
| Jul | 3.7 | Moderate |
| Aug | 3.5 | Moderate |
| Sep | 4.1 | Bright |
| Oct | 4.7 | Bright |
| Nov | 4.7 | Bright |
| Dec | 5.2 | Bright |
Where is Koidu?
Koidu sits at 8.6°N, 11.0°W, 381 m above sea level, in Sierra Leone. The nearest listed city is Segbwema, 72 km away.
Topography around Koidu
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Koidu.
Within 3 km, the terrain around Koidu has only modest variations in elevation — a maximum elevation change of 136 m around an average of 379 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 392 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,783 m.
The land around Koidu is covered by grassland (42%), artificial surfaces (30%) and trees (25%) within 3 km, trees (63%) and grassland (35%) within 16 km, and trees (80%) within 80 km.
Sierra Leone travel facts
- Travel advisory
- Level 2
- Exercise Increased Caution
- Power plugs
- Type D / G
- 230 V · 50 Hz
- Prices
- ≈ 24% of US
- price level, 2025
- GDP per capita
- $846
- 2025
- Happiness
- 3.3 / 10
- World Happiness, 2025
- Safe drinking water
- 11%
- of population, 2024
- Homicide rate
- 2.2
- per 100k, 2020
- Road deaths
- 33
- per 100k/yr, 2019
- Income group
- Low
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Koidu (8.6439°, -10.9714°, elevation 381 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).