Bo weather in May

In May, Bo sees average daytime highs of 31°C and overnight lows near 23°C, with 246 mm of rain across 27 wet days and about 12.4 hours of daylight. It is the 6th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 1% of the time in May, and the air most often feels oppressive.

Daylight stretches from about 12 h 18 min at the start of May to 12 h 24 min by month's end. Set against the rest of the year, May is Bo's 9th-clearest and 10th-windiest month. For the whole year in context, see Bo's year-round climate.

Daytime high
31°
6th warmest
Overnight low
23°
10th coldest
Rainfall
246 mm
27 wet days
Daylight
12 h 24 min
6:32 AM – 6:54 PM
Cloud cover
86%
9th clearest
Wind
4 km/h
10th windiest
Solar energy
4.32 kWh/m²
Travel score
2.7
out of 10

Bo is city of Sierra Leone.

Density
655/km²
people per km²
Founded
1787

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical May day in Bo reaches about 31°C in the afternoon and slips back to 23°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 33°C. Set against its neighbours, May runs about 2°C cooler than April and about 1°C warmer than June.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13224
23224
33124
43124
53124
63124
73124
83124
93124
103124
113124
123124
133124
143123
153123
163123
173123
183123
193123
203123
213123
223023
233023
243023
253023
263023
273023
283023
293023
303023
313023

How May really feels in Bo

Once humidity and wind are folded in, May averages 31 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
31
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in May is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Bo weather by month

How May compares with the rest of the year at a glance. May is the 6th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan33° / 22°173.711.64.1
Feb35° / 23°204.711.73.1
Mar34° / 24°5611.411.92.8
Apr33° / 24°12018.112.22.9
May31° / 23°2462712.42.7
Jun29° / 23°33328.912.52.8
Jul28° / 22°39629.112.43.3
Aug28° / 22°47629.412.33.4
Sep28° / 22°43329.3123.0
Oct29° / 22°24529.211.82.9
Nov30° / 22°10319.311.63.9
Dec31° / 22°266.411.55.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 1% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 6% of May, with mostly cloudy or overcast conditions the remaining 93%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
11288
21288
31189
41189
51090
61090
7991
8892
9892
10892
11892
12793
13793
14793
15694
16694
17595
18595
19595
20595
21496
22496
23496
24496
25496
26496
27496
28496
29496
30595
31595

Chance of precipitation in May

Any precipitation

Bo gets around 246 mm of rain over 27 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 87% and peaks near 95% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202531
Rain chance (%)
176
277
378
479
580
681
782
883
983
1084
1185
1286
1387
1488
1589
1690
1790
1890
1991
2091
2191
2292
2392
2492
2592
2693
2793
2893
2994
3094
3195

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the oppressive band about 68% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Muggy (%)Oppressive (%)Miserable (%)
116039
206139
306139
406139
506040
606139
706139
806139
906139
1006238
1106238
1206337
1306337
1406436
1506535
1606634
1706733
1806832
1906931
2007030
2107129
2207228
2307327
2407525
2507624
2607723
2707921
2808119
2908218
3008416
3108515

Wind in May

Winds average 4 km/h in May.

Across May, daily wind ranges from about 4 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
15calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 18 min at the start of May to 12 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 6 minutes over May. Sunrise moves from 6:36 AM to 6:32 AM, and sunset from 6:52 PM to 6:57 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.36:366:52
212.36:366:53
312.36:356:53
412.36:356:53
512.36:356:53
612.36:346:53
712.36:346:53
812.36:346:53
912.36:346:53
1012.36:336:53
1112.36:336:53
1212.36:336:53
1312.36:336:54
1412.46:336:54
1512.46:326:54
1612.46:326:54
1712.46:326:54
1812.46:326:54
1912.46:326:55
2012.46:326:55
2112.46:326:55
2212.46:326:55
2312.46:326:55
2412.46:326:56
2512.46:326:56
2612.46:326:56
2712.46:326:56
2812.46:326:56
2912.46:326:57
3012.46:326:57
3112.46:326:57

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.32 kWh/m².

For context, solar energy here swings from a low near 3.29 kWh/m² to a high of 5.6 kWh/m² in February across the year — May's 4.32 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.6Bright
24.5Bright
34.5Bright
44.5Bright
54.5Bright
64.5Bright
74.4Bright
84.4Bright
94.4Bright
104.4Bright
114.4Bright
124.4Bright
134.4Bright
144.3Bright
154.3Bright
164.3Bright
174.3Bright
184.3Bright
194.3Bright
204.3Bright
214.3Bright
224.3Bright
234.2Bright
244.2Bright
254.2Bright
264.2Bright
274.2Bright
284.2Bright
294.2Bright
304.1Bright
314.1Bright
Planning a trip in May

Hazard calendar for Bo

In seasonPeak

In May, Bo sits inside 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.

Monsoon
Dust
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is May a good time to visit Bo?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

2.7
Sightseeing
12th-best month of the year
3.9
Beach & pool
7th-best month of the year

May is a weaker month for outdoor sightseeing in Bo.

What to pack for Bo in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, Bo sees daytime highs around 31°C and nights near 23°C. Pack light clothes and rain gear. About 27 days see rain.

light clothesrain gear

UV index in Bo in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 12 (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.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeExtremeVery highAug 22UV 13Dec 15UV 8
UV index (midday)Level
Jan10Very high
Feb11Extreme
Mar12Extreme
Apr10Very high
May12Extreme
Jun11Extreme
Jul11Extreme
Aug13Extreme
Sep13Extreme
Oct12Extreme
Nov9Very high
Dec8Very high

Air quality in Bo in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May 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).

0306090120150180210JanFebMarAprMayJunJulAugSepOctNovDecUnhealthyVery unhealthyModerateGoodModeratePoorApr 9200 µg/m³Aug 2011 µg/m³
PM2.5 (µg/m³)Level
Jan70Unhealthy
Feb77Unhealthy
Mar194Very unhealthy
Apr202Very unhealthy
May33Moderate
Jun19Moderate
Jul13Moderate
Aug10Good
Sep11Good
Oct17Moderate
Nov25Moderate
Dec50Poor
Location & terrain

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.

BumpeNjalaKenemaMile 91SegbwemaMakeniKoiduLunsar

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.

3 km
93 m
16 km
328 m
80 km
820 m
treesshrubsgrasslandartificial surfaceswaterwetlandmangroves
May weather nearby: Bumpe 20 km · Njala 43 km · Kenema 61 km · Mile 91 77 km · Segbwema 87 km · Makeni 108 km · Koidu 113 km · Lunsar 119 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
Muslim 77%Christian 23%

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. 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).