, tempered by altitude, with a rainy season from October to April and a dry season in the austral winter, from June to August, while May and September are transitional months.
The city is located in the west of Brazil, in the state of Rondônia, at 12 degrees south latitude and 600 meters (2,000 feet) above sea level.
The dry period, from June to August, is also the coolest at night (in fact, we are in the austral winter). From time to time, in addition, there may be cool periods due to the winds that blow from the Argentine Pampas, with highs of about 18 °C (64 °F) or even below, while at night the temperature can drop below 10 °C (50 °F).
However, from mid-August to October, the temperature rises and the hottest days of the year are recorded, before the rains.
The best time to visit Vilhena is from June to August, being the dry season. In August, it is more likely to get very hot during the day.
. Here are the average temperatures.
January is generally a warm to hot, muggy month. The average temperature is of
24.7 °C, with a minimum of
21 °C and a maximum of
28.4 °C.

On the coldest nights of the month, the temperature usually drops to around
19.5 °C.

On the warmest days of the month, the temperature usually reaches around
31.5 °C.

Precipitation amounts to
290 mm, distributed over 19 days.
The day lasts on average 12 hours and 50 minutes.
The average humidity is 85%. Hence, the air is normally humid.
The average wind speed is of
11 kph.
February is generally a warm to hot, muggy month. The average temperature is of
24.7 °C, with a minimum of
21 °C and a maximum of
28.4 °C.

On the coldest nights of the month, the temperature usually drops to around
19 °C.

On the warmest days of the month, the temperature usually reaches around
31.5 °C.

Precipitation amounts to
295 mm, distributed over 18 days.
The day lasts on average 12 hours and 30 minutes.
The average humidity is 86%. Hence, the air is normally humid.
The average wind speed is of
10.4 kph.
March is generally a warm to hot, muggy month. The average temperature is of
25 °C, with a minimum of
21 °C and a maximum of
29 °C.

On the coldest nights of the month, the temperature usually drops to around
19 °C.

On the warmest days of the month, the temperature usually reaches around
32 °C.

Precipitation amounts to
295 mm, distributed over 18 days.
The day lasts on average 12 hours and 5 minutes.
The average humidity is 85%. Hence, the air is normally humid.
The average wind speed is of
10 kph.
April is generally a warm to hot, muggy month. The average temperature is of
25.1 °C, with a minimum of
20.7 °C and a maximum of
29.5 °C.

On the coldest nights of the month, the temperature usually drops to around
17 °C.

On the warmest days of the month, the temperature usually reaches around
32 °C.

Precipitation amounts to
180 mm, distributed over 12 days.
The day lasts on average 11 hours and 50 minutes.
The average humidity is 81%. Hence, the air is normally humid.
The average wind speed is of
10 kph.
May is generally a warm to hot, muggy month. The average temperature is of
24.1 °C, with a minimum of
19.3 °C and a maximum of
28.8 °C.

On the coldest nights of the month, the temperature usually drops to around
14.5 °C.

On the warmest days of the month, the temperature usually reaches around
31.5 °C.

Precipitation amounts to
70 mm, distributed over 9 days.
The day lasts on average 11 hours and 30 minutes.
The average humidity is 76%. Hence, the air is normally humid.
The average wind speed is of
10.2 kph.
June is generally a warm to hot month. The average temperature is of
23.5 °C, with a minimum of
18 °C and a maximum of
29.1 °C.

On the coldest nights of the month, the temperature usually drops to around
12.5 °C.

On the warmest days of the month, the temperature usually reaches around
31.5 °C.

Precipitation amounts to
35 mm, distributed over 5 days.
The day lasts on average 11 hours and 25 minutes.
The average humidity is 69%.
The average wind speed is of
10.9 kph.
July, the coolest month of the year, is generally a warm to hot month. The average temperature is of
23.5 °C, with a minimum of
17 °C and a maximum of
30 °C.

On the coldest nights of the month, the temperature usually drops to around
11 °C.

On the warmest days of the month, the temperature usually reaches around
32.5 °C.

Precipitation amounts to
10 mm, distributed over 4 days.
The day lasts on average 11 hours and 30 minutes.
The average humidity is 58%.
The average wind speed is of
11.4 kph.
August is generally a warm to hot month. However, there are remarkable differences between night and day. The average temperature is of
25 °C, with a minimum of
18.4 °C and a maximum of
31.5 °C.

On the coldest nights of the month, the temperature usually drops to around
12.5 °C.

On the warmest days of the month, the temperature usually reaches around
34 °C.

Precipitation amounts to
40 mm, distributed over 3 days.
The day lasts on average 11 hours and 40 minutes.
The average humidity is 54%.
The average wind speed is of
11.6 kph.
September, the hottest month of the year, is generally a warm to hot month. The average temperature is of
26.1 °C, with a minimum of
20.4 °C and a maximum of
31.8 °C.

On the coldest nights of the month, the temperature usually drops to around
15 °C.

On the warmest days of the month, the temperature usually reaches around
35 °C.

Precipitation amounts to
85 mm, distributed over 6 days.
The day lasts on average 12 hours and 0 minutes.
The average humidity is 64%.
The average wind speed is of
11.6 kph.
October is generally a warm to hot, muggy month. The average temperature is of
25.9 °C, with a minimum of
21 °C and a maximum of
30.8 °C.

On the coldest nights of the month, the temperature usually drops to around
18.5 °C.

On the warmest days of the month, the temperature usually reaches around
33.5 °C.

Precipitation amounts to
180 mm, distributed over 10 days.
The day lasts on average 12 hours and 25 minutes.
The average humidity is 74%. Hence, the air is normally humid.
The average wind speed is of
11.2 kph.
November is generally a warm to hot, muggy month. The average temperature is of
25.6 °C, with a minimum of
21.2 °C and a maximum of
30 °C.

On the coldest nights of the month, the temperature usually drops to around
18.5 °C.

On the warmest days of the month, the temperature usually reaches around
33 °C.

Precipitation amounts to
215 mm, distributed over 13 days.
The day lasts on average 12 hours and 40 minutes.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is of
11.3 kph.
December is generally a warm to hot, muggy month. The average temperature is of
25 °C, with a minimum of
21.2 °C and a maximum of
28.8 °C.

On the coldest nights of the month, the temperature usually drops to around
19 °C.

On the warmest days of the month, the temperature usually reaches around
31.5 °C.

Precipitation amounts to
315 mm, distributed over 17 days.
The day lasts on average 12 hours and 55 minutes.
The average humidity is 84%. Hence, the air is normally humid.
The average wind speed is of
11.1 kph.