Bo in Fall
In fall (September, October and November), Bo sees average daytime highs around 29°C and overnight lows near 22°C, with 781 mm of rain over about 78 wet days across the season. It is the 3rd-warmest season and the 2nd-wettest season.
Over the season highs climb from about 28°C in early September to 30°C by late November. The sky is clear or mostly clear about 4% of the time across fall, and the air most often feels oppressive.
Fall is Bo's 2nd-best season to visit on our travel score. For the whole year in context, see Bo's year-round climate.
- Avg daytime high
- 29°C
- 3rd-warmest season
- Avg overnight low
- 22°C
- Rainfall
- 781 mm
- 78 wet days
- Avg wind
- 4 km/h
- Travel score
- 3.3
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Bo in Fall
Over the season highs climb from about 28°C in early September to 30°C by late November.
A typical fall day in Bo reaches about 29°C and drops to 22°C overnight. The warmest of the three months is November, the coolest September.
How fall really feels in Bo
Once humidity and wind are folded in, fall brings about 68 days that feel above 32°C and 0 that feel at or below 0°C.
The story in fall is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
Bo weather by month
How the three fall months (September, October and November) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 33° / 22° | 17 | 3.7 | 11.6 | 4.1 |
| Feb | 35° / 23° | 20 | 4.7 | 11.7 | 3.1 |
| Mar | 34° / 24° | 56 | 11.4 | 11.9 | 2.8 |
| Apr | 33° / 24° | 120 | 18.1 | 12.2 | 2.9 |
| May | 31° / 23° | 246 | 27 | 12.4 | 2.7 |
| Jun | 29° / 23° | 333 | 28.9 | 12.5 | 2.8 |
| Jul | 28° / 22° | 396 | 29.1 | 12.4 | 3.3 |
| Aug | 28° / 22° | 476 | 29.4 | 12.3 | 3.4 |
| Sep | 28° / 22° | 433 | 29.3 | 12 | 3.0 |
| Oct | 29° / 22° | 245 | 29.2 | 11.8 | 2.9 |
| Nov | 30° / 22° | 103 | 19.3 | 11.6 | 3.9 |
| Dec | 31° / 22° | 26 | 6.4 | 11.5 | 5.0 |
Cloud cover in Fall
The sky is clear or mostly clear about 4% of the time across fall.
Chance of precipitation in Fall
Bo gets around 781 mm of rain over 78 wet days across fall. The line is the day-by-day chance of measurable precipitation.
Humidity in Fall
Most of fall feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Fall
Winds average 4 km/h across fall.
Sunrise & sunset in Fall
Daylight runs from about 12 h 12 min in early September to 11 h 36 min by late November. The lit band spans sunrise to sunset each day.
Solar energy in Fall
Average shortwave solar energy reaching the ground each day across fall, about 4.2 kWh/m².
Hazard calendar for Bo
In fall, Bo overlaps its monsoon season. The full year is below, with each hazard's peak months called out.
Bo's monsoon runs May–October, when most of the year's rain falls.
Bo sees seasonal dust haze (February–April), heaviest in February.
Is fall a good time to visit Bo?
Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
fall is a weaker month for outdoor sightseeing in Bo.
What to pack for Bo in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Bo sees daytime highs around 29°C and nights near 22°C. Pack light clothes and rain gear. About 78 days see rain.
UV index in Bo in Fall
Clear-sky midday UV across fall averages around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Bo peaks around August 22 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 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 | 11 | 12 | 10 | 12 | 11 | 11 | 13 | 13 | 12 | 9 | 8 |
| Level | Very high | Extreme | Extreme | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | Very high |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 10 | Very high |
| Feb | 11 | Extreme |
| Mar | 12 | Extreme |
| Apr | 10 | Very high |
| May | 12 | Extreme |
| Jun | 11 | Extreme |
| Jul | 11 | Extreme |
| Aug | 13 | Extreme |
| Sep | 13 | Extreme |
| Oct | 12 | Extreme |
| Nov | 9 | Very high |
| Dec | 8 | Very high |
Air quality in Bo in Fall
Average fine-particle pollution (PM2.5) through the year — so you can see where fall falls, not just the annual average.
Air quality in Bo is worst in April — around 202 µg/m³ PM2.5 (very unhealthy), about 19.4× the cleanest month (August, 10 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) | 70 | 77 | 194 | 202 | 33 | 19 | 13 | 10 | 11 | 17 | 25 | 50 |
| Level | Unhealthy | Unhealthy | Very unhealthy | Very unhealthy | Moderate | Moderate | Moderate | Good | Good | Moderate | Moderate | Poor |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 70 | Unhealthy |
| Feb | 77 | Unhealthy |
| Mar | 194 | Very unhealthy |
| Apr | 202 | Very unhealthy |
| May | 33 | Moderate |
| Jun | 19 | Moderate |
| Jul | 13 | Moderate |
| Aug | 10 | Good |
| Sep | 11 | Good |
| Oct | 17 | Moderate |
| Nov | 25 | Moderate |
| Dec | 50 | Poor |
Where is Bo?
Bo sits at 8.0°N, 11.7°W, 104 m above sea level, in Sierra Leone. The nearest listed city is Bumpe, 20 km away.
Topography around Bo
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Bo.
Within 3 km, the terrain around Bo has only modest variations in elevation — a maximum elevation change of 93 m around an average of 93 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 328 m; within 80 km, large variations in elevation — a maximum elevation change of 820 m.
The land around Bo is covered by artificial surfaces (56%) and trees (22%) within 3 km, trees (51%) and shrubs (35%) within 16 km, and trees (63%) and shrubs (20%) 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 Bo (7.9647°, -11.7383°, elevation 104 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.