Thinking about a trip to Nosy Be in the summer? You’ll find warm, muggy days, a good amount of sunshine, and regular bursts of rain. Average summer weather in Nosy Be brings daytime highs around 31°C (88°F), warm nights near 24°C (75°F), and sea temperatures that stay comfortable for swimming. This combo of heat, humidity, and tropical showers really shapes the island’s climate.
You’ll get a real tropical summer vibe, with short, heavy rain showers that usually give way to clearer skies. The air feels sticky, but breezes from the ocean help take the edge off.
Sunshine sticks around enough for you to enjoy being outside. The rainfall keeps the island’s landscapes lush and green.
When you know what to expect for temperature, rainfall, and daylight, you can plan your days better. Whether you’re after lazy beach time, checking out marine life, or wandering through the island’s green interior, understanding the summer climate helps you get the most out of your visit.
Overview of Nosy Be’s Summer Climate
Nosy Be sits off Madagascar’s northwest coast and has a tropical climate shaped by monsoon winds and the nearby Indian Ocean. Summers bring high heat, heavy rainfall, and sticky air, but also warm seas and long daylight hours.
Geographical Location and Climate Type
Nosy Be sits at about 13° south latitude, right off Madagascar’s Diana region. Its spot in the Indian Ocean means it gets both northwest monsoon winds and southeast trade winds.
This spot creates a tropical monsoon climate. You’ll feel hot temps all year, but the humidity and rain really ramp up from November through April.
The island gets about 1,700–1,800 mm of rain each year, with most of it falling in summer. Neighboring islands like Nosy Komba and Nosy Tanikely get similar weather, so the climate across the region stays pretty steady.
Warm ocean water surrounds Nosy Be, so you can swim year-round. In summer, the sea temperature often hits 29°C (84°F), making it perfect for marine activities—even when it’s rainy.
Typical Summer Weather Patterns
During summer, daily temperatures usually sit between 24°C (75°F) at night and 31–32°C (88–90°F) during the day. Sometimes, afternoons get even hotter, reaching up to 34°C.
Rain falls often and can be heavy. January gets the most rain, with nearly 400 mm over about 20 days. Showers are usually short but intense, and sometimes low-lying areas can flood.
Humidity stays high, usually above 75–80%, which makes the heat feel even stronger. Even with the rain, you’ll still see several hours of sunshine each day, usually 6–7 hours.
Tropical cyclones sometimes hit Nosy Be between November and March. Not every year brings a direct hit, but storms can bring strong winds and rough seas, so it’s good to stay aware.
Comparison to Other Seasons
Compared to the dry season (May to October), summer is hotter, wetter, and a lot more humid. In winter, highs drop a bit to about 29–30°C (84–86°F), and nights can cool off to 16–20°C (61–68°F).
Rain really drops outside of summer. For example, July gets only 20–25 mm across three days, while January can get over 390 mm. Summer definitely brings the most rain.
Sea temperatures change with the seasons, too. In summer, water warms to 28–29°C, while in winter it cools a bit to 25–26°C. Sunshine hours go up in the dry season, often 8–9 hours per day, compared to 6–7 hours in summer.
Summer stands out for high rainfall and humidity, while the dry season feels more comfortable and predictable.
Average Summer Temperatures in Nosy Be
Summer in Nosy Be brings steady warmth day and night, with only small changes from month to month. The air stays humid, the sea stays warm, and it rarely gets uncomfortably cool.
Daytime and Nighttime Temperature Ranges
You’ll see daytime highs between 29°C and 31°C (84°F–88°F) during summer, with February and March usually the warmest. The heat doesn’t really spike or drop much from week to week.
At night, temps usually fall to about 24°C–25°C (75°F–77°F). So evenings stay warm enough for being outside—no need for extra layers. Since Nosy Be is close to the equator, day and night temperatures don’t differ much.
High humidity makes the air feel even warmer. Light clothing and staying hydrated will help you stay comfortable.
Monthly Temperature Fluctuations
March often claims the title of hottest month, with daytime highs around 31°C (88°F). January and February are just a touch cooler, averaging about 30°C (86°F). These months also bring more rain, which makes the air feel heavier.
By April, things cool down a little, with daytime highs closer to 29°C (84°F). Nights stay steady at around 24°C (75°F), so you probably won’t notice much difference when sleeping.
Because Nosy Be’s climate is tropical, the range of temperatures through the year is pretty narrow. You won’t get sudden cold snaps or big drops. This makes it easy to plan outdoor stuff without worrying about wild weather changes.
Sea Temperature During Summer
The sea around Nosy Be stays super warm in summer. Average water temperatures run from 28°C to 29°C (82°F–84°F), perfect for swimming, snorkeling, or diving. You won’t need a wetsuit for most activities.
Ocean temps stay steady in January, February, and March. Even when it rains, the sea feels calm and inviting.
Since the water rarely goes below 25°C (77°F) any time of year, summer gives you some of the best conditions for marine fun. You can hang out in the water for hours without getting cold.
Rainfall Patterns and Precipitation
Rain shapes Nosy Be’s summer climate in a big way. Expect high rainfall totals, frequent showers, and a clear shift from the wettest months into the drier part of the year.
Summer Rainfall Amounts
Rainfall jumps up sharply in summer compared to the rest of the year. December, January, and February are the wettest, with monthly averages often hitting 300–500 mm.
That’s a lot of rain, especially when you consider the dry season totals can drop below 50 mm per month. The heavy rain feeds the island’s lush growth, but it can also limit outdoor plans if you’re not ready for it.
Rain usually falls in short but heavy bursts, not slow drizzles. These quick downpours can flood low spots or make dirt roads muddy and tough to cross. You’ll need to stay flexible with your plans during these months.
Frequency of Rainy Days
You’ll get a lot of days with measurable rainfall during summer. For example, January often sees rain on 20–25 days. That doesn’t mean it’s wet all day—showers are common, especially in the afternoon or evening.
On average, Nosy Be still gets 7–8 hours of sunshine per day, even in the rainy season. Mornings can be clear before storms build up later. The mix of sun and rain can make the weather feel unpredictable if you’re not used to the tropics.
Carrying an umbrella or a light rain jacket makes sense. Showers can start and stop quickly, so you might need to switch up your plans on the fly.
Transition from Rainy to Dry Season
The rainy season usually starts winding down in April. Rain totals drop fast, and by May, monthly averages often fall below 100 mm.
You’ll still see a few showers, but they’re shorter and less intense. Rainy days drop to fewer than 10 per month, and the humidity starts to let up.
Rivers and streams run fuller during this time, but trails and beaches get easier to reach. If you want warm weather with less rain, this transition period is a pretty good bet.
Sunshine Hours and Daylight
Day length and sunshine vary with the seasons in Nosy Be. Summer brings longer days and more sunshine, so planning outdoor activities gets a bit easier.
Average Daily Sunshine Hours
In summer, you can expect 7 to 9.5 hours of sunshine per day in Nosy Be. August usually stands out, with about 9.5 hours daily. By comparison, February—one of the wetter months—drops to around 5.7 hours.
These numbers depend on cloud cover and rain. Clearer skies mean more sun, while frequent rain blocks it.
Here’s a quick look:
| Month | Average Sunshine Hours (per day) |
|---|---|
| June | ~7.5 hours |
| July | ~8.5 hours |
| August | ~9.5 hours |
Sunshine hours increase toward August, giving you more reliable daylight for beach trips, diving, or exploring the island.
Variation in Sunshine Throughout Summer
Sunshine hours change slowly through summer. June brings moderate sun, but July and August get brighter and more consistent. This lines up with the drier season, when rain drops off.
Cloud cover fades as the season goes on. Fewer rainy days mean longer stretches of sun, especially in late summer.
If you want the most daylight, late summer is your best bet. August not only has the longest days but also the clearest skies, so you can enjoy more time outside with less worry about rain.
Humidity and Wind Conditions
Summer in Nosy Be means high humidity and steady breezes, which really affect how the weather feels. The air’s moisture can make days feel hotter, but winds help keep things from getting too stifling, especially near the coast.
Typical Humidity Levels in Summer
Humidity stays high during summer in Nosy Be. Average levels usually run between 70% and 85%, depending on rain and cloud cover. That’s typical for a tropical island, where warm seas keep pumping moisture into the air.
You’ll probably notice the air feels thick, especially in the afternoons. Nights stay humid too, which can make sleeping tough without a fan or some air movement.
Rain just adds to the dampness. Even on dry days, the plants and ocean keep the air moist. If you’re outdoors, expect sticky skin and slow-drying clothes.
Light cotton clothes and frequent hydration help a lot. Most hotels and guesthouses use fans or air conditioning to make it more comfortable inside.
Prevailing Winds and Breezes
Wind patterns in Nosy Be change with the seasons. In summer, the northwest monsoon winds blow more often, bringing moist air from the ocean and sometimes storms. These winds can feel great on the beach, but they might make the sea a bit rough.
Average wind speeds usually sit between 8–15 km/h (5–9 mph). Stronger gusts can happen during storms, but you’ll also get plenty of calm periods.
Onshore breezes help cool the coast during the day. Evenings often get quieter, so the air can feel even more humid.
If you’re planning to sail, dive, or snorkel, it’s smart to check the daily wind forecast. Breezes can make the heat easier to handle, but they also affect water clarity and safety for boating.
Best Time to Visit Nosy Be for Summer Weather
Nosy Be stays warm all year, but summer brings clearer skies and drier days. That makes it way easier to enjoy the island’s beaches, marine life, and outdoor activities.
Rainfall and humidity can change a lot, so picking the right time really helps you make the most of your trip.
Optimal Months for Outdoor Activities
Locals and travelers agree—the best time to visit Nosy Be for summer vibes is from May to October. During these months, daytime highs usually sit between 27°C and 30°C.
Evenings cool down a bit, dropping to around 23°C to 25°C. Rain doesn’t show up much, especially in July and August, which usually see fewer than 10 rainy days.
You also get more sun, with about 8–9 hours per day. That means more daylight for snorkeling, diving, or wandering through Lokobe Reserve.
The sea stays warm and calm, so swimming and boat trips feel extra inviting.
If you’re not a fan of big crowds, you might want to go in May, June, or September. The weather’s still great, but the island feels a bit quieter compared to the busy months of July and August.
| Month | Avg Temp (°C) | Rainfall (mm) | Rainy Days |
|---|---|---|---|
| May | 28 | ~60 | 8 |
| July | 27 | ~29 | 6 |
| September | 28 | ~40 | 7 |
Travel Tips for Summer Visitors
Pack light, breathable clothes because the air stays humid, even when it’s supposed to be drier. Toss a light jacket or sweater in your bag, just in case the nights get cool near the coast.
Don’t forget reef-safe sunscreen, a hat, and some insect repellent. Mosquitoes don’t disappear in the dry months, so you’ll still want some protection.
Drink plenty of water, since the humidity can make the heat feel way more intense.
Try to plan outdoor activities for the early morning or late afternoon when the heat is more comfortable. The midday sun might not look too bad on a thermometer, but it can feel surprisingly harsh.
If you’re heading there in July or August, go ahead and book your accommodations and excursions early. School holidays in a lot of countries make these months busier, so hotels, tours, and flights fill up fast.