Porto Alegre

Planning a trip or just curious about the weather in Porto Alegre? In this section, you will find the most up-to-date information on weather conditions, as well as detailed forecasts and helpful charts.

The climate in Porto Alegre, located in São Tomé and Príncipe, is characterized as tropical. Temperatures here remain high and remarkably stable throughout the year, with average values fluctuating by only a few degrees, typically ranging from 24°C to 27°C. This ensures warm weather almost constantly, making the town an attractive destination at any time of year in terms of thermal comfort.

Despite the stable temperatures, Porto Alegre experiences a distinct change in seasons based on the amount of precipitation and rainy days. There is a drier season, which usually falls between June and September. During these months, the number of rainy days is minimal, and precipitation is practically absent, especially in July. The rest of the year, from October to May, constitutes the wet season. At this time, the number of rainy days increases significantly, peaking in November and December. Interestingly, even during the wettest period, the total amount of precipitation remains relatively low, which may indicate frequent but light rain or drizzle rather than heavy downpours.

The temperature regime in Porto Alegre is remarkably stable throughout the year, which is characteristic of an equatorial climate. The average annual temperature fluctuates only slightly, staying within a comfortable warm range. The hottest months are usually March and April, when the average temperature reaches 26.7°C, and daytime highs in March can rise to 27.7°C. The "coolest" month is considered to be July, with an average temperature of 23.9°C and minimum night temperatures around 23.1°C. Thus, the annual range of average temperatures is only about 2.8 degrees, highlighting the mildness of the climate.

From January to May, Porto Alegre experiences its warmest weather. Monthly average temperatures during this time stay at 26°C or higher, peaking in February, March, and April (26.6°C - 26.7°C). Daytime highs in these months often reach or approach 27°C, ranging from 26.9°C (January) to 27.7°C (March), creating the hot and humid feel typical of the tropics. It is important to note that the difference between day and night temperatures is minimal, often not exceeding 1.5-2°C. This means that nights also remain very warm, with temperatures rarely dropping below 25°C during the hottest months.

From June to September, there is a slight decrease in temperature, which can be described as a "fresher" period, though the weather remains very warm. In July and August, the coolest months, the average temperature is around 24°C (23.9°C in July, 24.0°C in August). Daytime highs during this time are usually around 24.6°C - 24.8°C, while nightly lows drop to 23.1°C - 23.2°C. As in the hot season, daily temperature fluctuations remain small, providing a steady and mild temperature backdrop even during these conditionally "cool" months for the equatorial zone.

Porto Alegre shows a clear seasonality in the distribution of precipitation throughout the year. The town experiences two main periods: a relatively dry season and a long wet season. The nature of precipitation is primarily rain, which is typical for the tropical climate of São Tomé and Príncipe. Snow does not occur here.

The dry season in Porto Alegre usually lasts from June to September. During this time, precipitation decreases sharply. The driest month is July, when on average not a single millimeter of rain falls, and the number of rainy days is minimal—only about 3. June, August, and September are also characterized by very low precipitation (averaging only 1 mm) and a small number of rainy days (from 6 to 9). This makes this period the most favorable for those who prefer to avoid frequent rain.

The wet season spans most of the year, from October to May. The amount of precipitation and the number of rainy days are significantly higher during these months. The highest rainfall occurs in November (averaging 9 mm), as well as December (8 mm) and October and April (6 mm each). In terms of frequency, December leads (about 28 rainy days), followed by November (about 27 days), and January and October (about 25 days each). Interestingly, even in the wettest months, the total amount of precipitation in millimeters is not very high, which may suggest frequent but not always heavy or prolonged rains.

When heading to Porto Alegre, it is important to consider its tropical climate with high humidity and consistently warm temperatures year-round. Your wardrobe should be based on light, breathable clothing made from natural fabrics like cotton or linen. Don't forget a swimsuit, as the weather is always perfect for relaxing by the water. Sunscreen with high SPF, sunglasses, and a hat (such as a sun hat or cap) are essential for protection against the strong sun, especially from June to September when there is less rainfall. Comfortable walking shoes, such as sandals or light sneakers, will also be indispensable for exploring the town.

Porto Alegre has a pronounced wet season that lasts roughly from October to May. During these months, although the total precipitation might not be very high, the number of rainy days increases significantly—from 19 to 28 per month. Therefore, a light waterproof raincoat or a compact umbrella is highly recommended during this period. Quick-drying clothing will also come in very handy. While temperatures remain high (averaging 25-27°C), the frequent rain can make it feel quite humid.

In the drier season, from June to September, the number of rainy days drops sharply, especially in July when precipitation is almost non-existent. During this time, the focus shifts to sun protection, but a light wrap or a long-sleeved shirt might still be useful for evening walks or for sun protection during the day. Regardless of the season, insect repellent will be a useful addition to your luggage, especially if you plan to spend time in nature or outdoors in the evening. The principle of layering is less relevant here due to the consistently high temperatures, but having a light sweater or shawl can be comfortable in air-conditioned spaces.