Fall in São Tomé brings a blend of tropical warmth and frequent showers that shape daily life on the island. You’ll usually see average daytime temperatures hovering around 27–29 °C (81–84 °F), with high humidity. Rainfall picks up in October and November, making these some of the wettest months of the year.
Even with all that rain, the island’s landscapes stay lush, and the sea feels warm enough for a swim.
If you’re planning to spend time outdoors, you’ll notice the skies often flip between cloudy and clear. Short, heavy downpours are common.
The air stays humid, but the steady warmth makes it comfortable enough for exploring the coast, hitting the beaches, or checking out São Tomé’s cultural spots.
Overview of Fall Climate in Sao Tome
During the fall, you get steady warmth, high humidity, and a definite shift toward wetter weather. Rainfall ramps up through the season, but temperatures stick to a pretty stable, comfortable range for most outdoor plans.
Tropical Climate Characteristics
Sao Tome sits just north of the equator, so its climate stays equatorial tropical all year. You won’t notice much change in temperature between seasons, but rainfall and humidity really define the weather here.
Average daily highs in the fall hover around 79–81°F (26–27°C). Nighttime lows usually stick close to 74–77°F (23–25°C).
These narrow ranges show off the island’s consistent tropical warmth.
Humidity stays very high, often near 100%. The air feels heavy and muggy, and even at night you probably won’t get much relief from the heat.
Cloud cover creeps in as fall moves on. Early September gives you more sunny breaks, but by November, overcast skies dominate.
This shift affects how much light you get and how much direct sun you’ll feel during the day.
The Atlantic Ocean nearby helps keep the climate steady. Sea surface temperatures rise from about 78°F (26°C) in early fall to 81°F (27°C) by late fall, which adds to the humid feel.
Seasonal Weather Patterns
Rainfall shows the biggest change through fall. Early September feels dry, with just about 0.1 inches of rain in a typical 31-day stretch.
By November, totals can hit 3 inches or more, and the chance of a wet day jumps from 3% to nearly 45%.
This big increase marks the start of one of the island’s rainy seasons. Showers come fast and heavy, and overcast skies are pretty common.
Daylight hours barely shift because Sao Tome sits right on the equator. You get about 12 hours of daylight all season, with only tiny changes in sunrise and sunset.
Winds slow down a bit, dropping from 10 mph in early fall to 9 mph by late fall, blowing mostly from the south. They aren’t strong, but they help move the humid air around.
If you’re planning outdoor activities, keep the rising rainfall and cloud cover in mind. Early fall brings more sunshine, while late fall gets wetter and cloudier, so excursions can feel less predictable.
Average Fall Temperatures in Sao Tome
In fall, Sao Tome stays warm and sticky, and the difference between day and night temperatures is barely noticeable. Temperatures hold steady through the season, with only tiny shifts from September to November.
Daytime and Nighttime Temperature Ranges
During fall, daytime highs in Sao Tome usually sit close to 26°C (79°F). They rarely climb above 27°C (81°F) or drop below 25°C (77°F).
This makes the climate pretty stable—no wild swings like you find in other places.
Nighttime lows are almost the same as daytime highs. Most nights stay around 25°C (77°F) and rarely dip under 24°C (75°F).
Evenings feel just as warm as the afternoons.
Because of this, you get that constant tropical feel. Locals and travelers often use air conditioning or fans since the air doesn’t cool down much after dark.
If you’re visiting, pack light, breathable clothes that work for both day and night.
Monthly Temperature Trends
From September to November, Sao Tome’s temperature pattern barely changes. In September, daily averages hang around 26°C, and by November, they’re still in that same narrow band.
Unlike rainfall, which really jumps in fall, temperatures stay put. The hottest months come earlier in March, while July brings the coolest stretch.
Fall sits in the middle, offering steady warmth.
Sea surface temperature also climbs during fall, going from about 25°C (77°F) in early September to almost 27°C (81°F) by late November.
This slow warming keeps the water nice for swimming and other activities.
With both air and water temperatures staying consistent, you can count on reliable warmth—no sudden surprises—which makes it easy to plan outside.
Rainfall and Precipitation During Fall
Rainfall steadily increases through fall in São Tomé as the islands shift into the wetter season. You’ll see a big difference between the early and later months, with rain totals rising fast and rainy days getting more common.
Monthly Rainfall Totals
Rainfall in São Tomé during fall moves upward in a clear trend. September often starts off mild, with totals around 70–90 mm and fewer rainy days.
By October, rain picks up sharply, averaging about 150–180 mm, and you can expect rain on nearly half the days.
November is the wettest fall month. It averages about 220 mm of rain spread over 16–18 days, making it one of the rainiest stretches of the year.
Daytime temps still hover near 27–28°C, but humidity rises, and sunshine hours dip compared to the dry season.
| Month | Avg. Rainfall (mm) | Rainy Days (approx.) | Avg. Temp (°C) |
|---|---|---|---|
| September | 70–90 | 8–10 | 27–28 |
| October | 150–180 | 12–14 | 27–28 |
| November | ~220 | 16–18 | 28 |
November really stands out as the peak of the rainy season, while September feels more like a transition.
Rainfall Distribution Across the Island
Rain doesn’t fall evenly across São Tomé. The southwestern slopes get the heaviest precipitation because moist air rises from the Gulf of Guinea.
The northeastern coast sees much less, sometimes less than a tenth of what the southwest gets.
If you’re staying near the capital, São Tomé, you’ll notice a mix. The city averages about 1,400 mm annually, but the nearby highlands can get several times more.
A short drive can bring totally different weather.
Travelers often run into quick changes—from heavy downpours in the forested interior to lighter showers or even dry spells by the coast.
If you’re moving around the island in fall, be ready for variable conditions. Rain gear is a must if you plan to explore beyond the beaches.
Humidity and Air Quality in the Fall Months
In fall, São Tomé’s humidity rises as rainfall returns after the dry stretch. These higher moisture levels affect how comfortable you feel and the air quality.
Average Humidity Levels
From September to November, humidity usually sits between 79% and 82%. This is a jump from the drier months of July and August.
By October and November, the mix of warmer temps and steady rainfall pushes humidity close to the year’s highs.
You’ll really notice it in the evenings and early mornings when the air feels extra heavy. Daytime levels stay up there too, especially after it rains.
| Month | Avg. Humidity | Rainfall |
|---|---|---|
| September | ~79% | 17 mm |
| October | ~81% | 70–90 mm |
| November | ~82% | 100+ mm |
So, fall isn’t the most humid season of the year, but it definitely marks a return to wetter, stickier weather.
High Humidity Effects
When humidity climbs above 80%, the air feels less comfortable, even if temperatures aren’t extreme. Sweat just doesn’t evaporate as quickly, which can make outdoor stuff feel draining.
You might pick up on a musty smell indoors if places aren’t well-ventilated. Clothes and bedding can take forever to dry, and mold can pop up in damp corners.
If you’re visiting, pack light, breathable fabrics and plan to take breaks during the muggiest parts of the day.
If you have any respiratory issues, high humidity can make the air feel heavier, though São Tomé’s coastal breezes usually help keep things from getting too stagnant.
Comparison With PrÃncipe and Other Regions
Sao Tome and PrÃncipe both have a tropical setting, but the two islands don’t always get the same weather. Elevation, coastal exposure, and rainfall patterns make noticeable differences that matter for travel or daily plans.
Weather Differences Between Sao Tome and PrÃncipe
Sao Tome, the bigger island, has more varied terrain. The central mountains rise above 2,000 meters, bringing cooler nights and heavier rain up high.
On the coast, daytime temps usually stick near 26–28°C, with humidity staying high all year.
PrÃncipe is smaller and less mountainous, so there’s less contrast between the inland and the coast. Average temperatures also hover around 26°C, but rain spreads out more evenly.
The island gets a bit less rain than the wettest parts of Sao Tome, so it’s a little drier overall.
During fall, Sao Tome often gets short, intense showers, especially on the southwest coast where yearly totals can top 7,000 mm.
PrÃncipe, while humid, usually avoids such extremes. If you’re traveling, you might find Sao Tome’s weather less predictable, while PrÃncipe offers steadier conditions and fewer sudden downpours.
Regional Climate Variations
Within Sao Tome, conditions can change fast between regions. The northeastern coast is much drier, with some places getting just 700 mm of rain per year.
Meanwhile, the southwestern slopes get some of the heaviest rainfall in West Africa. Moist winds hit the volcanic mountains and drop tons of rain.
Villages up in the hills are cooler, sometimes dropping to 18–20°C at night. Coastal towns, though, stay warm and humid, with barely any relief after sunset.
PrÃncipe doesn’t show such big contrasts since its terrain is lower and less spread out. Still, you’ll notice slightly cooler evenings inland compared to the shoreline.
Packing for a mountain hike on Sao Tome means different clothes than you’d need for a beach stay on PrÃncipe.
Best Time to Visit Sao Tome in the Fall
Fall in Sao Tome brings a mix of short rain showers and warm tropical days. You’ll get moderate humidity, steady temperatures, and fewer tourists than during the busy dry season.
Ideal Weather Windows
From September through November, Sao Tome moves from the end of the long dry season into a wetter stretch. September is usually the driest month, with barely any rain and average highs near 29 °C (84 °F).
By October and November, showers show up more often, but they’re usually quick and followed by sunshine.
Humidity ticks up a bit in October, making the air feel warmer, but temperatures stay steady between 27–29 °C (81–84 °F).
The sea remains warm at about 26–27 °C (79–81 °F), so swimming and snorkeling are still great.
If you’re into hiking, September is your best bet with drier trails and less mud. October and November work for travelers who don’t mind some rain in exchange for greener scenery and more active waterfalls.
Travel Tips for Fall Visitors
Bring light, breathable clothes for the daytime. Toss in a light rain jacket, just in case you get caught in a sudden shower.
You’ll want waterproof shoes or maybe sandals if you plan to wander through rainforests or along the coast.
Fewer tourists show up in the fall, so you might actually score better lodging and enjoy quieter beaches. Some rural roads get muddy after heavy rain, so plan for a little extra travel time if you’re heading between towns.
October and November are fantastic for birdwatching, since lots of migratory species show up. If you like cultural experiences, check out the cocoa harvest season in the fall—you can get a close look at local farming traditions.