Climate and average weather in São Tomé
In São Tomé, the weather is muggy, hot, wet, and mostly cloudy and remarkably steady, with daytime highs holding near hot levels all year. The wettest stretch peaks around November.
Over the course of the year, the temperature in São Tomé typically varies from 24°C to 28°C, and is rarely below 23°C or above 29°C. March is the hottest month of the year, while July is the coldest.
Based on the travel score, the best time of year to visit São Tomé for warm-weather activities is from early June to late September.
- Hottest
- Mar
- 28°
- Coldest
- Jul
- 24°
- Wettest
- Nov
- 210 mm
- Driest
- Jul
- 8 mm
- Rain / yr
- 1256 mm
- 189 wet days
- Daylight
- 12.0–12.0 h
- shortest–longest
- Elevation
- 140 m
- 0.3°N
- Clearest
- Jun
- 65% cloud
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.
São Tomé 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 early June to late September.
Temperature through the year
Daily average highs and lows in São Tomé, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
Temperatures in São Tomé stay fairly even through the year, without a distinct hot or cool season. The warmest month is March, with an average high of 28°C and low of 26°C; the coolest is July, with an average low of 24°C and high of 24°C.
Days typically run about 1°C warmer than nights year-round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 27 | 28 | 28 | 28 | 27 | 25 | 24 | 24 | 25 | 26 | 26 | 27 |
| Avg low (°C) | 26 | 26 | 26 | 26 | 26 | 24 | 24 | 24 | 24 | 25 | 25 | 25 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 27 | 26 |
| Feb | 28 | 26 |
| Mar | 28 | 26 |
| Apr | 28 | 26 |
| May | 27 | 26 |
| Jun | 25 | 24 |
| Jul | 24 | 24 |
| Aug | 24 | 24 |
| Sep | 25 | 24 |
| Oct | 26 | 25 |
| Nov | 26 | 25 |
| Dec | 27 | 25 |
Average hourly temperature in São Tomé
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 March afternoons, near 28°C, and coldest before dawn in July, near 24°C.
São Tomé 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 | 27° / 26° | 135 | 23.6 | 12 | 4.3 |
| Feb | 28° / 26° | 113 | 19.3 | 12 | 4.6 |
| Mar | 28° / 26° | 133 | 20.5 | 12 | 4.4 |
| Apr | 28° / 26° | 130 | 18.7 | 12 | 4.8 |
| May | 27° / 26° | 119 | 17 | 12 | 5.3 |
| Jun | 25° / 24° | 23 | 4 | 12 | 7.5 |
| Jul | 24° / 24° | 8 | 2 | 12 | 8.0 |
| Aug | 24° / 24° | 14 | 2.6 | 12 | 7.9 |
| Sep | 25° / 24° | 46 | 7.8 | 12 | 6.9 |
| Oct | 26° / 25° | 152 | 21.5 | 12 | 4.9 |
| Nov | 26° / 25° | 210 | 25.7 | 12 | 4.1 |
| Dec | 27° / 25° | 174 | 26.1 | 12 | 4.1 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
São Tomé gets about 1256 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 7.5 months, from around Oct 5 to May 20, peaking in November at about 87% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jul 30.
November is the wettest month by volume, with 210 mm over about 26 wet days; July is the driest, with 8 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 76 | 69 | 66 | 62 | 54 | 15 | 7 | 8 | 27 | 69 | 85 | 84 |
| Rain days | 24 | 19 | 21 | 19 | 17 | 4 | 2 | 3 | 8 | 22 | 26 | 26 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 76 | 24 |
| Feb | 69 | 19 |
| Mar | 66 | 21 |
| Apr | 62 | 19 |
| May | 54 | 17 |
| Jun | 15 | 4 |
| Jul | 7 | 2 |
| Aug | 8 | 3 |
| Sep | 27 | 8 |
| Oct | 69 | 22 |
| Nov | 85 | 26 |
| Dec | 84 | 26 |
Monthly rainfall
Over a full year, São Tomé collects about 1256 mm of rain across 189 wet days — roughly 105 mm in an average month.
It doesn’t fall evenly. November is the wettest month with 210 mm, while July is the driest at just 8 mm. The three wettest months alone bring about 43% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 135 | 113 | 133 | 130 | 119 | 23 | 8 | 14 | 46 | 152 | 210 | 174 |
| Rain days | 24 | 19 | 21 | 19 | 17 | 4 | 2 | 3 | 8 | 22 | 26 | 26 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 135 | 24 |
| Feb | 113 | 19 |
| Mar | 133 | 21 |
| Apr | 130 | 19 |
| May | 119 | 17 |
| Jun | 23 | 4 |
| Jul | 8 | 2 |
| Aug | 14 | 3 |
| Sep | 46 | 8 |
| Oct | 152 | 22 |
| Nov | 210 | 26 |
| Dec | 174 | 26 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In São Tomé, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.
The clearer part of the year begins around May 29 and lasts for 4.4 months, ending around October 9. The clearest month is June, when the sky is clear, mostly clear, or partly cloudy 41% of the time on average.
The cloudier part of the year begins around December 24 and lasts for 5.1 months, ending around May 28. The cloudiest month is March, when it is overcast or mostly cloudy 79% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 28 | 25 | 21 | 22 | 29 | 41 | 40 | 41 | 36 | 31 | 31 | 32 |
| Cloudier (%) | 72 | 75 | 79 | 78 | 71 | 59 | 60 | 59 | 64 | 69 | 69 | 68 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 28 | 72 |
| Feb | 25 | 75 |
| Mar | 21 | 79 |
| Apr | 22 | 78 |
| May | 29 | 71 |
| Jun | 41 | 59 |
| Jul | 40 | 60 |
| Aug | 41 | 59 |
| Sep | 36 | 64 |
| Oct | 31 | 69 |
| Nov | 31 | 69 |
| Dec | 32 | 68 |
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. Close to the equator, São Tomé barely changes through the year: days stay near 12 hours of light in every season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 | 12.0 |
| Sunrise (AM) | 5:43 | 5:48 | 5:43 | 5:33 | 5:29 | 5:33 | 5:38 | 5:37 | 5:27 | 5:18 | 5:19 | 5:30 |
| Sunset (PM) | 5:42 | 5:47 | 5:43 | 5:34 | 5:30 | 5:34 | 5:39 | 5:38 | 5:27 | 5:18 | 5:18 | 5:29 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 12.0 | 5:43 | 5:42 |
| Feb | 12.0 | 5:48 | 5:47 |
| Mar | 12.0 | 5:43 | 5:43 |
| Apr | 12.0 | 5:33 | 5:34 |
| May | 12.0 | 5:29 | 5:30 |
| Jun | 12.0 | 5:33 | 5:34 |
| Jul | 12.0 | 5:38 | 5:39 |
| Aug | 12.0 | 5:37 | 5:38 |
| Sep | 12.0 | 5:27 | 5:27 |
| Oct | 12.0 | 5:18 | 5:18 |
| Nov | 12.0 | 5:19 | 5:18 |
| Dec | 12.0 | 5:30 | 5:29 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
São Tomé averages about 3 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 2 and 6 days.
The sunnier stretch runs 3.6 months, from around May 2 to Aug 19. The sunniest month is June, with roughly 6 sunny days (gloomy).
The greyest month is September, down near 3 sunny days — about 53% fewer than the June peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 3 | 3 | 3 | 3 | 4 | 5 | 4 | 4 | 3 | 3 | 3 | 3 |
| Sky | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy |
| Sunny days | Sky | |
|---|---|---|
| Jan | 3 | Gloomy |
| Feb | 3 | Gloomy |
| Mar | 3 | Gloomy |
| Apr | 3 | Gloomy |
| May | 4 | Gloomy |
| Jun | 5 | Gloomy |
| Jul | 4 | Gloomy |
| Aug | 4 | Gloomy |
| Sep | 3 | Gloomy |
| Oct | 3 | Gloomy |
| Nov | 3 | Gloomy |
| Dec | 3 | Gloomy |
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.
São Tomé is humid all year round — on a typical day the air feels at least humid, and there is no real dry season to wait for.
The stickiest month is January, when it feels muggy, oppressive or miserable about 100% of the time. Even in January, the mildest month, the air is dry or comfortable only 0% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Humid (%) | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 |
| Muggy (%) | 0 | 0 | 0 | 0 | 1 | 30 | 63 | 56 | 12 | 1 | 0 | 0 |
| Oppressive (%) | 91 | 76 | 68 | 67 | 83 | 70 | 36 | 43 | 88 | 99 | 100 | 99 |
| Miserable (%) | 9 | 24 | 32 | 33 | 16 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
| Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|
| Jan | 0 | 0 | 91 | 9 |
| Feb | 0 | 0 | 76 | 24 |
| Mar | 0 | 0 | 68 | 32 |
| Apr | 0 | 0 | 67 | 33 |
| May | 0 | 1 | 83 | 16 |
| Jun | 0 | 30 | 70 | 0 |
| Jul | 1 | 63 | 36 | 0 |
| Aug | 1 | 56 | 43 | 0 |
| Sep | 0 | 12 | 88 | 0 |
| Oct | 0 | 1 | 99 | 0 |
| Nov | 0 | 0 | 100 | 0 |
| Dec | 0 | 0 | 99 | 1 |
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 São Tomé is typically light breeze, near 16 km/h, and varies moderately with the seasons.
The windier part of the year lasts 5.0 months, from around May 20 to Oct 19. The windiest month is July, averaging about 20 km/h (breezy).
The calmer part of the year runs from around Oct 20 to May 19, with January the calmest month at about 12 km/h.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 12 | 13 | 13 | 12 | 15 | 20 | 20 | 20 | 19 | 16 | 14 | 13 |
| Feels | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | breezy | breezy | light breeze | light breeze | light breeze | light breeze |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 12 | light breeze |
| Feb | 13 | light breeze |
| Mar | 13 | light breeze |
| Apr | 12 | light breeze |
| May | 15 | light breeze |
| Jun | 20 | light breeze |
| Jul | 20 | breezy |
| Aug | 20 | breezy |
| Sep | 19 | light breeze |
| Oct | 16 | light breeze |
| Nov | 14 | light breeze |
| Dec | 13 | light breeze |
Hazard calendar for São Tomé
When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.
São Tomé's rainy season runs October–May, when most of the year's rain falls.
Best time to visit São Tomé
To characterize how pleasant the weather is in São Tomé throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around mid June, São Tomé is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.
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 São Tomé for general outdoor tourist activities is from early June to late September, with a peak score in the last week of July.
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) | 4.3 | 4.5 | 4.4 | 4.8 | 5.4 | 7.5 | 8.0 | 7.9 | 6.8 | 4.9 | 4.1 | 4.1 |
| Rating | fair | fair | fair | fair | fair | good | ideal | ideal | good | fair | fair | fair |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 4.3 | fair |
| Feb | 4.5 | fair |
| Mar | 4.4 | fair |
| Apr | 4.8 | fair |
| May | 5.4 | fair |
| Jun | 7.5 | good |
| Jul | 8.0 | ideal |
| Aug | 7.9 | ideal |
| Sep | 6.8 | good |
| Oct | 4.9 | fair |
| Nov | 4.1 | fair |
| Dec | 4.1 | fair |
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 São Tomé for hot-weather activities is from late May to late September, with a peak score in the third week of June.
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 São Tomé, 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.
São Tomé packs about the same all year — highs hold near 28°C. Across the year the things worth having are light clothes, rain gear, sun protection and a windbreaker.
In March, São Tomé sees daytime highs around 28°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 21 days see rain.
Sea temperature near São Tomé
Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.
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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 29 | 29 | 29 | 29 | 28 | 27 | 26 | 26 | 26 | 27 | 28 | 28 |
| Comfort | Tropical | Tropical | Tropical | Tropical | Tropical | Warm | Warm | Warm | Warm | Warm | Warm | Tropical |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 29 | Tropical |
| Feb | 29 | Tropical |
| Mar | 29 | Tropical |
| Apr | 29 | Tropical |
| May | 28 | Tropical |
| Jun | 27 | Warm |
| Jul | 26 | Warm |
| Aug | 26 | Warm |
| Sep | 26 | Warm |
| Oct | 27 | Warm |
| Nov | 28 | Warm |
| Dec | 28 | Tropical |
UV index (midday) in São Tomé 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 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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 11 | 12 | 14 | 13 | 11 | 9 | 9 | 8 | 12 | 13 | 12 | 11 |
| Level | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | Very high | Very high | Extreme | Extreme | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 11 | Extreme |
| Feb | 12 | Extreme |
| Mar | 14 | Extreme |
| Apr | 13 | Extreme |
| May | 11 | Extreme |
| Jun | 9 | Very high |
| Jul | 9 | Very high |
| Aug | 8 | Very high |
| Sep | 12 | Extreme |
| Oct | 13 | Extreme |
| Nov | 12 | Extreme |
| Dec | 11 | Extreme |
Average hourly UV index in São Tomé
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 March 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) | 7.5 | 8 | 8 | 8 | 7.5 | 7 | 7 | 7 | 8 | 8 | 8 | 7.5 |
| UV ≥ 6 (h/day) | 5.5 | 6 | 6.5 | 6 | 5.5 | 4.5 | 4.5 | 4.5 | 6 | 6 | 5.5 | 5.5 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 7.5 | 5.5 |
| Feb | 8 | 6 |
| Mar | 8 | 6.5 |
| Apr | 8 | 6 |
| May | 7.5 | 5.5 |
| Jun | 7 | 4.5 |
| Jul | 7 | 4.5 |
| Aug | 7 | 4.5 |
| Sep | 8 | 6 |
| Oct | 8 | 6 |
| Nov | 8 | 5.5 |
| Dec | 7.5 | 5.5 |
Air quality in São Tomé 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 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).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 22 | 24 | 15 | 11 | 12 | 16 | 17 | 13 | 8 | 5 | 8 | 15 |
| Level | Moderate | Moderate | Moderate | Good | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 22 | Moderate |
| Feb | 24 | Moderate |
| Mar | 15 | Moderate |
| Apr | 11 | Good |
| May | 12 | Moderate |
| Jun | 16 | Moderate |
| Jul | 17 | Moderate |
| Aug | 13 | Moderate |
| Sep | 8 | Good |
| Oct | 5 | Good |
| Nov | 8 | Good |
| Dec | 15 | Moderate |
Growing season
São Tomé 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. São Tomé banks about 5,708 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) | 506 | 471 | 531 | 511 | 504 | 443 | 431 | 435 | 440 | 473 | 468 | 495 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 506 |
| Feb | 471 |
| Mar | 531 |
| Apr | 511 |
| May | 504 |
| Jun | 443 |
| Jul | 431 |
| Aug | 435 |
| Sep | 440 |
| Oct | 473 |
| Nov | 468 |
| Dec | 495 |
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.
São Tomé receives about 5.2 kWh/m² a day of solar energy — bright — and it stays remarkably steady, holding between 4.9 and 5.5 kWh/m² all year. For solar panels, output here is a flat line, not a seasonal wave.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.1 | 5.4 | 5.5 | 5.3 | 5.0 | 5.0 | 5.1 | 5.3 | 5.3 | 5.1 | 5.0 | 4.9 |
| Level | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 5.1 | Bright |
| Feb | 5.4 | Bright |
| Mar | 5.5 | Bright |
| Apr | 5.3 | Bright |
| May | 5.0 | Bright |
| Jun | 5.0 | Bright |
| Jul | 5.1 | Bright |
| Aug | 5.3 | Bright |
| Sep | 5.3 | Bright |
| Oct | 5.1 | Bright |
| Nov | 5.0 | Bright |
| Dec | 4.9 | Bright |
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.
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
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).