São Tomé weather in May

In May, São Tomé sees average daytime highs of 27°C and overnight lows near 26°C, with 119 mm of rain across 17 wet days and about 12 hours of daylight. It is the 5th-warmest and 7th-wettest month of the year here.

Day-to-day highs hold fairly steady near 27°C through the month. The sky is clear or mostly clear about 13% of the time in May, and the air most often feels oppressive.

Daylight stretches from about 12 hours at the start of May to 12 hours by month's end. Set against the rest of the year, May is São Tomé's 8th-clearest and 6th-windiest month. For the whole year in context, see São Tomé's year-round climate.

Daytime high
27°
5th warmest
Overnight low
26°
9th coldest
Rainfall
119 mm
17 wet days
Daylight
12 hours
5:29 AM – 5:30 PM
Cloud cover
73%
8th clearest
Wind
15 km/h
6th windiest
Solar energy
5.05 kWh/m²
Travel score
5.3
out of 10

São Tomé is capital city of São Tomé and Príncipe.

Density
3,135/km²
people per km²
Founded
1485

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 27°C through the month.

A typical May day in São Tomé reaches about 27°C in the afternoon and slips back to 26°C overnight — a 1°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 28°C. Set against its neighbours, May runs about 1°C cooler than April and about 2°C warmer than June.

20°23°25°28°30°151015202531
Avg high (°C)Avg low (°C)
12826
22826
32726
42726
52726
62726
72726
82726
92726
102726
112726
122726
132726
142726
152726
162726
172726
182726
192726
202726
212726
222726
232726
242725
252625
262625
272625
282625
292625
302625
312625

São Tomé weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 26°13523.6124.3
Feb28° / 26°11319.3124.6
Mar28° / 26°13320.5124.4
Apr28° / 26°13018.7124.8
May27° / 26°11917125.3
Jun25° / 24°234127.5
Jul24° / 24°82128.0
Aug24° / 24°142.6127.9
Sep25° / 24°467.8126.9
Oct26° / 25°15221.5124.9
Nov26° / 25°21025.7124.1
Dec27° / 25°17426.1124.1

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 13% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 17% of May, with mostly cloudy or overcast conditions the remaining 71%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12377
22377
32476
42476
52575
62773
72773
82872
93070
103070
113169
123169
133169
143268
153268
163268
173268
183268
193169
203169
213169
223169
233169
243169
252971
262971
272971
283070
293070
303169
313268

Chance of precipitation in May

Any precipitation

São Tomé gets around 119 mm of rain over 17 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 54% and peaks near 66% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
166
266
365
465
564
663
763
862
961
1060
1160
1259
1358
1458
1557
1656
1756
1855
1954
2053
2152
2251
2349
2447
2546
2644
2742
2840
2938
3035
3133

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 83% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Muggy (%)Oppressive (%)Miserable (%)
107129
207129
307228
407228
507228
607327
707426
807426
907525
1007624
1107723
1207921
1308020
1418019
1518118
1618316
1718415
1818514
1918613
2018811
2118910
222899
232908
242917
252926
263925
273934
283943
294933
304942
315932

Wind in May

Winds average 15 km/h in May.

Across May, daily wind ranges from about 13 km/h on the calmest days to 18 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1415light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1916light breeze
2016light breeze
2116light breeze
2216light breeze
2317light breeze
2417light breeze
2517light breeze
2617light breeze
2717light breeze
2818light breeze
2918light breeze
3018light breeze
3118light breeze

Sunrise & sunset in May

DaylightNight

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

Days grow by about 0 minutes over May. Sunrise moves from 5:30 AM to 5:30 AM, and sunset from 5:31 PM to 5:31 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.05:305:31
212.05:305:31
312.05:305:30
412.05:305:30
512.05:295:30
612.05:295:30
712.05:295:30
812.05:295:30
912.05:295:30
1012.05:295:30
1112.05:295:30
1212.05:295:30
1312.05:295:30
1412.05:295:30
1512.05:295:30
1612.05:295:30
1712.05:295:30
1812.05:295:30
1912.05:295:30
2012.05:295:30
2112.05:295:30
2212.05:295:30
2312.05:295:30
2412.05:295:30
2512.05:295:30
2612.05:295:30
2712.05:295:31
2812.05:305:31
2912.05:305:31
3012.05:305:31
3112.05:305:31

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.05 kWh/m².

For context, solar energy here swings from a low near 4.89 kWh/m² to a high of 5.48 kWh/m² in March across the year — May's 5.05 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.2Bright
55.2Bright
65.2Bright
75.1Bright
85.1Bright
95.1Bright
105.1Bright
115.1Bright
125.1Bright
135.1Bright
145.1Bright
155.1Bright
165.0Bright
175.0Bright
185.0Bright
195.0Bright
205.0Bright
215.0Bright
225.0Bright
235.0Bright
245.0Bright
255.0Bright
265.0Bright
275.0Bright
285.0Bright
295.0Bright
305.0Bright
315.0Bright
Planning a trip in May

Hazard calendar for São Tomé

In seasonPeak

In May, São Tomé sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

São Tomé's rainy season runs October–May, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is May a good time to visit São Tomé?

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

5.3
Sightseeing
5th-best month of the year
5.4
Beach & pool
5th-best month of the year

May is a reasonable time to visit São Tomé for sightseeing.

What to pack for São Tomé in May

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

In May, São Tomé sees daytime highs around 27°C and nights near 26°C. Pack rain gear. Worth having: light clothes and sun protection. About 17 days see rain.

rain gearlight clothessun protection

Sea temperature near São Tomé in May

The nearest coast averages about 28°C in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in March at about 29°C and coldest in August near 26°C.

The water stays above 20°C all year — warm enough for a swim any month.

24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan29Tropical
Feb29Tropical
Mar29Tropical
Apr29Tropical
May28Tropical
Jun27Warm
Jul26Warm
Aug26Warm
Sep26Warm
Oct27Warm
Nov28Warm
Dec28Tropical

UV index in São Tomé in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks 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 São Tomé peaks around March 21 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near August 12 at about 9 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeMar 21UV 14Aug 12UV 9
UV index (midday)Level
Jan11Extreme
Feb12Extreme
Mar14Extreme
Apr13Extreme
May11Extreme
Jun9Very high
Jul9Very high
Aug8Very high
Sep12Extreme
Oct13Extreme
Nov12Extreme
Dec11Extreme

Air quality in São Tomé 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 São Tomé is worst in February — around 24 µg/m³ PM2.5 (moderate), about 4.6× the cleanest month (October, 5 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateGoodModerateFeb 1023 µg/m³Oct 175 µg/m³
PM2.5 (µg/m³)Level
Jan22Moderate
Feb24Moderate
Mar15Moderate
Apr11Good
May12Moderate
Jun16Moderate
Jul17Moderate
Aug13Moderate
Sep8Good
Oct5Good
Nov8Good
Dec15Moderate
Location & terrain

Where is São Tomé?

São Tomé sits at 0.3°N, 6.7°E, 140 m above sea level, in Sao Tome and Principe. The nearest listed city is Port-Gentil, 257 km away.

Topography around São Tomé

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of São Tomé.

Within 3 km, the terrain around São Tomé has only modest variations in elevation — a maximum elevation change of 111 m around an average of 23 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,396 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,938 m.

The land around São Tomé is covered by water (43%), trees (31%) and artificial surfaces (24%) within 3 km, water (60%) and trees (36%) within 16 km, and water (90%) within 80 km.

3 km
111 m
16 km
1,396 m
80 km
1,938 m
treesgrasslandartificial surfaceswater
May weather nearby: Port-Gentil 257 km · Akanda 291 km · Libreville 303 km · Owendo 309 km · Ntoum 337 km · Bata 378 km · Lambaréné 407 km · Malabo 443 km

Sao Tome and Principe travel facts

Travel advisory
Level 3
Reconsider Travel
Power plugs
Type C / F
220 V · 50 Hz
Prices
≈ 61% of US
price level, 2025
GDP per capita
$4,084
2025
Safe drinking water
37%
of population, 2024
Homicide rate
3.2
per 100k, 2011
Road deaths
27.9
per 100k/yr, 2019
Income group
Lower middle
World Bank
Religion
Catholic 56%none 21%other 6%Adventist 4%

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 São Tomé (0.3376°, 6.7299°, elevation 140 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).