Climate - Porto Velho (Rondônia)

Porto Velho's climate is tropical, with a rainy season from October to April and a dry season from June to August, while May and September are transitional months.
The city is the capital of the state of Rondônia and is located in the northwest of Brazil, at 8 degrees south latitude, on the banks of the Madeira River, a tributary of the Amazon River. We are in the Amazon rainforest.
It is generally hot even in the austral winter, however, sometimes, especially in June and July, cool air masses from the south can lower the daytime temperatures to around or below 20 °C (68 °F), while night lows can drop to about 13 °C (55 °F).
Instead, from mid-August to October there can be very hot periods, in which the highest temperatures of the year are reached.

Best Time

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The best time to visit Porto Velho is from June to August, being the dry season.

Porto Velho - Climate data

In Porto Velho, the average temperature of the coldest month (July) is of 27.2 °C (80.9 °F), that of the warmest month (September) is of 28.5 °C (83.4 °F). Here are the average temperatures.
In Porto Velho, precipitation amounts to 2255 millimeters (88.8 inches) per year: it is therefore abundant. It ranges from 25 mm (1 in) in the driest month (July) to 320 mm (12.6 in) in the wettest ones (January, December) Here is the average precipitation.
In Porto Velho, there are on average around 1990 sunshine hours per year. Here are the average hours of sunshine per day.

Porto Velho - Weather by month

Based on the period 1991-2020

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In January, the weather in Porto Velho is usually warm to hot and muggy. The average temperature is of 27.3 °C (81 °F), with a minimum of 23.4 °C (74.2 °F) and a maximum of 31.2 °C (88.1 °F).
On the coldest nights of the month, the temperature usually drops to around 22 °C (71.5 °F).
On the warmest days of the month, the temperature usually reaches around 34 °C (93 °F).
Precipitation amounts to 320 mm (12.6 in), distributed over 19 days.
The day lasts on average 12 hours and 35 minutes.
There are on average 3.5 hours of sunshine per day. So, the sun shines 27% of the time.
The average humidity is 87%. Hence, the air is normally humid.
The average wind speed is 5 kph (3 mph).

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In February, the weather in Porto Velho is usually warm to hot and muggy. The average temperature is of 27.2 °C (81 °F), with a minimum of 23.5 °C (74.2 °F) and a maximum of 30.9 °C (87.7 °F).
On the coldest nights of the month, the temperature usually drops to around 22 °C (71.5 °F).
On the warmest days of the month, the temperature usually reaches around 33.5 °C (92.5 °F).
Precipitation amounts to 315 mm (12.4 in), distributed over 19 days.
The day lasts on average 12 hours and 25 minutes.
There are on average 3.5 hours of sunshine per day. So, the sun shines 28% of the time.
The average humidity is 87%. Hence, the air is normally humid.
The average wind speed is 5 kph (3 mph).

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In March, the weather in Porto Velho is usually warm to hot and muggy. The average temperature is of 27.5 °C (81 °F), with a minimum of 23.6 °C (74.4 °F) and a maximum of 31.4 °C (88.4 °F).
On the coldest nights, the temperature usually drops to around 22 °C (71.5 °F).
On the warmest days, the temperature usually reaches around 34 °C (93 °F).
Precipitation amounts to 275 mm (10.8 in), distributed over 20 days.
The day lasts on average 12 hours and 5 minutes.
There are on average 4 hours of sunshine per day. So, the sun shines 33% of the time.
The average humidity is 87%. Hence, the air is normally humid.
The average wind speed is 5 kph (3 mph).

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In April, the weather in Porto Velho is usually very hot and muggy. The average temperature is of 27.7 °C (82 °F), with a minimum of 23.6 °C (74.6 °F) and a maximum of 31.7 °C (89.1 °F).
On the coldest nights, the temperature usually drops to around 21.5 °C (70.5 °F).
On the warmest days, the temperature usually reaches around 34 °C (93.5 °F).
Precipitation amounts to 250 mm (9.8 in), distributed over 17 days.
The day lasts on average 11 hours and 55 minutes.
There are on average 4.5 hours of sunshine per day. So, the sun shines 39% of the time.
The average humidity is 86%. Hence, the air is normally humid.
The average wind speed is 5 kph (3 mph).

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In May, the weather in Porto Velho is usually warm to hot and muggy. The average temperature is of 27.3 °C (81 °F), with a minimum of 23.1 °C (73.6 °F) and a maximum of 31.4 °C (88.6 °F).
On the coldest nights, the temperature usually drops to around 20 °C (68 °F).
On the warmest days, the temperature usually reaches around 34 °C (93.5 °F).
Precipitation amounts to 125 mm (4.9 in), distributed over 11 days.
The day lasts on average 11 hours and 40 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 51% of the time.
The average humidity is 84%. Hence, the air is normally humid.
The average wind speed is 5 kph (3 mph).

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In June, the weather in Porto Velho is usually warm to hot and muggy. The average temperature is of 27.2 °C (81 °F), with a minimum of 22.4 °C (72.2 °F) and a maximum of 32 °C (89.6 °F).
On the coldest nights, the temperature usually drops to around 19 °C (66 °F).
On the warmest days, the temperature usually reaches around 34 °C (93.5 °F).
Precipitation amounts to 50 mm (2 in), distributed over 4 days.
The day lasts on average 11 hours and 35 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 65% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is 5 kph (3 mph).

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In July, the least warm month of the year, the weather in Porto Velho is usually warm to hot and muggy. The average temperature is of 27.2 °C (81 °F), with a minimum of 21.3 °C (70.3 °F) and a maximum of 33 °C (91.4 °F).
On the coldest nights of the month, the temperature usually drops to around 17 °C (62.5 °F).
On the warmest days of the month, the temperature usually reaches around 35.5 °C (95.5 °F).
Precipitation amounts to 25 mm (1 in), distributed over 3 days.
The day lasts on average 11 hours and 40 minutes.
There are on average 8.5 hours of sunshine per day. So, the sun shines 72% of the time.
The average humidity is 72%. Hence, the air is normally humid.
The average wind speed is 5 kph (3 mph).

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In August, the weather in Porto Velho is usually very hot. The average temperature is of 28.1 °C (83 °F), with a minimum of 21.9 °C (71.4 °F) and a maximum of 34.3 °C (93.7 °F).
On the coldest nights of the month, the temperature usually drops to around 17.5 °C (64 °F).
On the warmest days of the month, the temperature usually reaches around 36.5 °C (98 °F).
Precipitation amounts to 35 mm (1.4 in), distributed over 4 days.
The day lasts on average 11 hours and 50 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 64% of the time.
The average humidity is 69%.
The average wind speed is 5 kph (3 mph).

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In September, the hottest month of the year, the weather in Porto Velho is usually very hot and muggy. The average temperature is of 28.5 °C (83 °F), with a minimum of 22.9 °C (73.3 °F) and a maximum of 34.1 °C (93.5 °F).
On the coldest nights, the temperature usually drops to around 19.5 °C (67.5 °F).
On the warmest days, the temperature usually reaches around 36.5 °C (98 °F).
Precipitation amounts to 120 mm (4.7 in), distributed over 11 days.
The day lasts on average 12 hours and 5 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 52% of the time.
The average humidity is 74%. Hence, the air is normally humid.
The average wind speed is 5 kph (3 mph).

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In October, the weather in Porto Velho is usually very hot and muggy. The average temperature is of 28.3 °C (83 °F), with a minimum of 23.3 °C (74 °F) and a maximum of 33.3 °C (91.9 °F).
On the coldest nights, the temperature usually drops to around 21.5 °C (70.5 °F).
On the warmest days, the temperature usually reaches around 36 °C (97 °F).
Precipitation amounts to 195 mm (7.7 in), distributed over 13 days.
The day lasts on average 12 hours and 20 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 44% of the time.
The average humidity is 80%. Hence, the air is normally humid.
The average wind speed is 5 kph (3 mph).

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In November, the weather in Porto Velho is usually very hot and muggy. The average temperature is of 27.8 °C (82 °F), with a minimum of 23.5 °C (74.3 °F) and a maximum of 32.2 °C (90 °F).
On the coldest nights, the temperature usually drops to around 21.5 °C (71 °F).
On the warmest days, the temperature usually reaches around 35 °C (95 °F).
Precipitation amounts to 225 mm (8.9 in), distributed over 16 days.
The day lasts on average 12 hours and 30 minutes.
There are on average 4.5 hours of sunshine per day. So, the sun shines 37% of the time.
The average humidity is 84%. Hence, the air is normally humid.
The average wind speed is 5 kph (3 mph).

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In December, the weather in Porto Velho is usually warm to hot and muggy. The average temperature is of 27.4 °C (81 °F), with a minimum of 23.4 °C (74.2 °F) and a maximum of 31.3 °C (88.4 °F).
On the coldest nights of the month, the temperature usually drops to around 22 °C (71.5 °F).
On the warmest days of the month, the temperature usually reaches around 34.5 °C (93.5 °F).
Precipitation amounts to 320 mm (12.6 in), distributed over 19 days.
The day lasts on average 12 hours and 35 minutes.
There are on average 4 hours of sunshine per day. So, the sun shines 32% of the time.
The average humidity is 86%. Hence, the air is normally humid.
The average wind speed is 5 kph (3 mph).