If you’re planning a trip to São Tomé, you’ll want to catch the weather when it’s at its best. This little island in the Gulf of Guinea has a tropical climate, and you can really feel the difference between the dry and rainy seasons. The best time to visit São Tomé usually falls during the dry months from June to September, and again from December to February. Rainfall drops, skies clear up, and you get more chances to enjoy the outdoors.
You’ll get warm temperatures all year, but the season you pick really shapes your experience. Dry months are ideal for hiking, whale watching, and lazy days on the beach. When the rains come, the scenery turns lush, waterfalls roar, and you’ll probably see fewer tourists.
If you get a handle on the seasonal patterns, you can plan your trip around what you care about most. Maybe you want to trek in the rainforest, tour cocoa plantations, or just relax on a quiet beach. Every season brings something different, so it helps to know what to expect.
Overview of Sao Tome, Sao Tome and Principe Climate
The islands sit close to the Equator, so you’ll get a tropical climate with steady warmth, high humidity, and clear wet and dry periods. Conditions shift by season and even by which part of São Tomé you’re in.
Equatorial Location and Weather Patterns
São Tomé and Príncipe sit just north of the Equator in the Gulf of Guinea, so the climate stays hot and humid most of the year. Daylight doesn’t swing much—it’s about 12 hours all year—so you won’t see big changes in sunlight.
Two main seasons set the tone. The dry season runs from June to September. The wettest months hit in April–May and again in October–November.
Even in the “dry” months, clouds often hang around, and humidity rarely drops below 75–80%.
All that warmth and moisture helps the islands stay green. Inland hills, especially around Pico de São Tomé (2,024 meters), trap mist and clouds. That’s why some areas get drenched while others stay drier.
Temperature Ranges Throughout the Year
Temperatures barely budge in São Tomé. In the capital, daytime highs hover at about 30 °C (86 °F) from February to April, then dip to around 27–28 °C (81–82 °F) in July and August.
At night, lows sit between 20–23 °C (68–73 °F). You won’t need heavy clothes, even in the “cooler” months. Outdoor activities are always an option.
The sea stays warm too. Water temperatures go from 26 °C (79 °F) in the cooler months to 29 °C (84 °F) when it’s hotter. Swimming and diving? Always possible.
Rainfall Variations by Region
Rainfall changes a lot depending on where you are. The north, including the capital, gets about 900 mm (35 in) of rain per year. That’s because it sits in the “rain shadow” of the southern mountains, so it’s drier.
Meanwhile, the southern slopes can soak up to 5,000 mm (195 in) a year. Príncipe gets more rain too, averaging around 2,000 mm (79 in) near Santo António.
You might find dry weather in the north, while the south gets drenched. If you plan to hike or hit the rainforests, expect it to be wetter and bring the right gear.
Dry Seasons: The Best Time to Visit
The islands get two main dry seasons. These bring less rain, clearer skies, and more comfortable weather for exploring. That’s when most people come for hiking, birdwatching, or just hanging out at the beach.
Gravana: June to September
Locals call the long dry season gravana. It runs from June through September. Expect slightly cooler days, lower humidity, and barely any rain compared to the rest of the year.
Hiking becomes a lot easier—rainforest trails dry out, and you can spot Pico Cão Grande rising above the trees. Waterfalls and coastal viewpoints are also more accessible.
Cultural events pop up too. July and August bring festivals, open-air music, and traditional performances. It’s a great way to see daily life beyond the beaches.
Highlights of Gravana:
- Best hiking conditions
- Cooler, less humid weather
- Cultural festivals in July–August
- Clearer views of natural landmarks
Gravanita: December to February
The short dry season, or gravanita, lasts from December to February. Temperatures stay warm all year, but you’ll get drier weather and more sun during these months. It’s a solid time if you want to mix culture with wildlife.
Birdwatching really shines. Many species show off their mating plumage, making them easier to spot. Marine turtles nest from November through March, so you might catch them laying eggs or see hatchlings head for the sea.
Diving and snorkeling get better too—calmer seas, clearer water. Carnival celebrations often happen during this stretch, so you can catch traditional dances and music.
Highlights of Gravanita:
- Good birdwatching opportunities
- Turtle nesting season
- Improved diving conditions
- Carnival and cultural events
Rainy Seasons: What to Expect
Rain shapes daily life and travel in São Tomé and Príncipe. The islands stay warm, but heavy showers and high humidity can change how you get around and what feels fun.
Main Rainy Periods and Their Impact
The islands get two main rainy seasons. The longer one runs from March to May, and a shorter but still wet period hits in October and November. Expect frequent downpours, often in the afternoon or evening.
Rain can get intense. Some areas see over 200 mm per month during the wettest weeks. Roads outside São Tomé City can turn muddy and tough to pass. If you’re heading inland, plan for slower travel.
Humidity jumps, often above 80%. The heat feels heavier, but temperatures stay steady, usually between 26–30°C. Rain rarely lasts all day, but you’ll want a light waterproof jacket if you’re out and about.
Fewer tourists visit during these months, so you might find lower prices and quieter beaches. Transport schedules can be limited, and delays happen, especially if you’re heading to Príncipe.
Nature and Activities During Wet Months
The landscape changes fast in the rainy months. Forests thicken, rivers swell, and waterfalls look their best. If you love photography or nature walks, this is when the islands are at their greenest.
Birdwatching is great, especially from October to March, when migratory species show up. Endemic birds, like the São Tomé ibis, get more active too.
Cocoa and coffee plantations thrive. You can visit, watch the harvest, and taste fresh beans or chocolate. These activities work even if it’s raining.
Outdoor hikes are doable but watch your step. Trails get slippery, and river crossings can be tricky. Guided tours help, especially in Obô Natural Park, where weather can shift quickly after storms.
If you’d rather stay inside, São Tomé City has museums, markets, and local restaurants. It’s easy to wait out the afternoon showers with a good meal.
Monthly Weather Breakdown
Sao Tome and Principe split the year into two dry seasons and two wetter periods. Rain, temperature, and humidity all shift as the months go by, which changes what you’ll want to do.
Weather Highlights by Month
December to February brings the first dry season. Days stay warm—about 27–30°C. Seas are calm, and rain is rare, so it’s great for beach trips and hiking.
March to May is the long rainy season. Rain increases, especially inland, and trails can get muddy. On the bright side, forests, waterfalls, and birdwatching are at their best.
The second dry season runs from June to September. It’s the most stable stretch—cooler, less humid, and barely any rain. Hiking, snorkeling, and whale watching are all in top form.
October and November kick off the short rainy season. Showers return, but the landscape gets really green. Cocoa harvests happen too, which adds some local flavor.
| Month Range | Season | Key Conditions |
|---|---|---|
| Dec–Feb | Dry | Warm, sunny, low rainfall |
| Mar–May | Wet | Heavy rain, lush scenery |
| Jun–Sep | Dry | Cooler, clear, best for outdoor activities |
| Oct–Nov | Wet | Short rains, cocoa harvest |
Tourist Seasons and Crowd Levels
December to February and June to September are the busiest. These dry months are the best time to visit if you want steady weather. Expect more people on the beaches, higher prices, and fewer open spots at eco-lodges, especially on Príncipe.
March to May is quieter. Rain picks up, but you’ll find lower costs and fewer crowds. It’s a good time if you like peace and don’t mind getting wet.
October and November bring a moderate number of visitors. Rain increases, but cultural events and harvests keep things interesting. Travel feels more laid-back, and you might score better deals on places to stay.
Weather Differences Between Sao Tome and Príncipe Island
Sao Tome and Príncipe both have tropical climates, but their size, terrain, and position in relation to the wind make for some real differences. Rain, humidity, and seasonal changes vary between the islands, which can affect your plans.
Climate Comparison: Sao Tome vs. Príncipe
On Sao Tome, temperatures stick between 27°C and 29°C. The capital and northeast coast sit in a rain-shadow, so they get less than 600 mm of rain per year. The southern and western slopes, though, are much wetter—up to 6,000 mm.
Príncipe Island is smaller but catches more consistent rain. Its southern half, covered in dense forest, is especially wet thanks to moist winds from the southwest. The northern coast is drier and easier to explore during the rainy season.
Here’s a quick look at the differences:
| Feature | Sao Tome (main island) | Príncipe Island |
|---|---|---|
| Avg. Temp (°C) | 27–29 | 26–28 |
| Rainfall (dry areas) | ~600 mm | ~1,500 mm |
| Rainfall (wet areas) | Up to 6,000 mm | 3,000–4,000 mm |
So, you might get sunnier days in Sao Tome’s northeast, while Príncipe stays greener and more humid.
Unique Weather Features of Príncipe
Príncipe’s weather feels different because of its small size and mountains. Moist Atlantic air rises over the island’s peaks, causing frequent showers and heavy clouds—especially in the south. That keeps the forests lush and perfect for birdwatching or spotting orchids.
Rainfall spreads more evenly through the year on Príncipe. Even in the dry season, you’ll probably see some short showers. This keeps things cooler and more humid, with highs around 26–28°C.
One neat thing? After the rain, the air clears up and you get bright skies and sharp views. It’s great for photography and hiking. That mix of quick rain and blue skies really sets Príncipe apart from Sao Tome.
Top Activities and Natural Attractions by Season
The islands really change with the seasons, and rainfall and sea conditions play a big part. When the dry months roll in, you get clear waters and steady trails.
Wetter months turn the forests lush and set the waterfalls roaring. Wildlife seems to come and go with the seasons, so timing your trip makes a difference depending on what you want to see.
Beaches and Marine Life: Lagoa Azul, Praia Banana, Praia Jalé, Praia Inhame
If you love snorkeling, check out Lagoa Azul in the dry season from June to September. The water stays calm and clear, and you’ll spot plenty of tropical fish.
It’s easy to swim here, and the marine reserve feels welcoming.
On Príncipe, Praia Banana sits in a sheltered bay with golden sand and sparkling water. July and August are the best months.
Those months bring calm seas and sunny skies, perfect for kayaking or diving.
Praia Jalé sits on the quieter southern coast of São Tomé. It’s famous for turtle nesting, and if you come between September and March, you might catch turtles laying eggs at night.
Just nearby, Praia Inhame offers a mix of forest views and good swimming during the dry months. People often use it as a base for boat rides to Rolas Islet, where you can literally stand on the equator.
| Beach | Best Season | Highlight Activity |
|---|---|---|
| Lagoa Azul | Jun–Sep | Snorkeling, kayaking |
| Praia Banana | Jul–Aug | Swimming, diving |
| Praia Jalé | Sep–Mar | Turtle nesting observation |
| Praia Inhame | Jun–Sep | Swimming, trips to Rolas |
Hiking and Rainforest Exploration: Pico Cao Grande
Pico Cao Grande towers over the rainforest in southern São Tomé, rising more than 300 meters. You’ll find the trails easiest between June and September, when it rains less and the paths stay dry.
Local guides lead you through thick forest, pointing out rare plants and birds. If you want the best views of the peak, visit in the dry season when clouds don’t hang around as much.
April and October bring heavier rain, and the forest gets trickier to cross. But if you’re into photography, the waterfalls look their best and the landscape glows green.
The rainy season colors really pop, even if hiking gets a bit tougher.
Wildlife Experiences: Turtle and Whale Watching
From July to September, you might spot humpback whales off the west coast of São Tomé. Local boats, often leaving from towns like Neves, head out when the sea is calm, and honestly, that’s when you’ll get the best views.
People often see dolphins playing in these waters too. It’s not rare to catch a glimpse if you’re out on a boat.
Turtles come ashore to nest mostly between September and March, especially on beaches like Praia Jalé and Praia Inhame. Conservation groups sometimes invite visitors to join their guided night walks, letting you watch the turtles without bothering them.
Over on Príncipe, the beaches near Bom Bom get turtle activity too, but you’ll probably find fewer tourists there. The dry months make it easier to reach these spots, though the best nesting times do line up with the start of the rainy season.
If you time things right, you could actually catch both the whales and turtles in one trip. Not a bad way to spend a holiday, right?