Porto Velho climate — normals and trends
Porto Velho (Brazil) has a tropical monsoon climate (Am) under the Köppen-Geiger classification. Its mean annual temperature is 26.0 °C and it receives 2,133 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is September (27.0 °C on average) and the coldest is May (25.4 °C). Rainfall peaks in March.
Porto Velho averages 0 frost days, 207 hot days (≥ 30 °C) and 250 rainy days per year.
Porto Velho has warmed by +1.2 °C between 1940 and 2025, or +0.14 °C per decade. This trend is statistically significant.
The hottest day of the period reached 39.1 °C (on 15 September 1961) and the coldest 12.1 °C (on 19 July 1975).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
Porto VelhoRondônia
- coords
- -8.76°, -63.90°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
26.0°C
Average daily high
30.4°C
Average daily low
23.0°C
Annual rainfall
2,133mm
Sunshine / day
9.3h
Mean relative humidity
86%
Average peak wind
7.9km/h
Seasonal range
1.6°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
207 d/yr
Rainy days (≥ 1 mm)
250 d/yr
Annual snowfall
0.0 cm
Average feels-like high
36.5 °C
Average feels-like low
27.4 °C
Average peak gust
23.5 km/h
Tropical nights (≥ 20 °C)
357 d/yr
Solar radiation
17.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.2 °C
since 1940
+0.1 °C per decade · r² = 0.51 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
39.1 °C
15 September 1961
Coldest day
12.1 °C
19 July 1975
Wettest day
155 mm
11 December 2017
Windiest day
22.2 km/h
20 August 1965
Strongest gust
51.5 km/h
20 August 1965
Hottest feels-like
44.3 °C
22 October 1999
Coldest feels-like
8.9 °C
18 July 1975
Sunniest day
12.5 h
28 December 1948
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 30.2 °C | +0.6 °C | 225 mm | -74 mm |
| Feb | 29.5 °C | 0.0 °C | 345 mm | +46 mm |
| Mar | 30.0 °C | +0.5 °C | 360 mm | +52 mm |
| Apr | 30.4 °C | +0.9 °C | 276 mm | +46 mm |
| May | 30.9 °C | +1.6 °C | 76 mm | -51 mm |
| Jun | 31.0 °C | +1.2 °C | 20 mm | -23 mm |
| Jul | 32.6 °C | +1.7 °C | 0 mm | -22 mm |
| Aug | 33.7 °C | +1.4 °C | 23 mm | -20 mm |
| Sep | 33.5 °C | +1.3 °C | 76 mm | -19 mm |
| Oct | 32.3 °C | +0.8 °C | 110 mm | -59 mm |
| Nov | 31.2 °C | +0.7 °C | 252 mm | +30 mm |
| Dec | 29.7 °C | -0.1 °C | 437 mm | +161 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Porto Velho?
Porto Velho has a tropical monsoon climate (Köppen Am). Over 1940-2025, the average annual temperature is 26.0 °C and it receives 2,133 mm of precipitation per year.
What is the hottest day ever recorded in Porto Velho?
The hottest day measured in Porto Velho between 1940 and 2025 was 15 September 1961, reaching 39.1 °C.
What is the coldest day in Porto Velho?
The coldest day measured in Porto Velho between 1940 and 2025 was 19 July 1975, at 12.1 °C.
Does it snow in Porto Velho?
Almost never: Porto Velho sees virtually no snow, with about 0 frost days per year.
Has the climate of Porto Velho warmed?
Yes: Porto Velho warmed by +1.2 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Porto Velho?
The wettest day measured in Porto Velho between 1940 and 2025 was 11 December 2017, with 155 mm of rain in 24 hours.
What was the windiest day in Porto Velho?
The windiest day measured in Porto Velho between 1940 and 2025 was 20 August 1965, with winds reaching 22.2 km/h.
What is the warmest month in Porto Velho?
The warmest month in Porto Velho is September (27.0 °C on average); the coldest is May (25.4 °C).
How much does it rain in Porto Velho?
Porto Velho receives on average 2,133 mm of precipitation per year, spread over about 250 rainy days.
Is it sunny in Porto Velho?
Porto Velho gets on average 9.3 hours of sunshine per day, roughly 3,395 hours per year over 1940-2025.
Are there tropical nights in Porto Velho?
Yes: Porto Velho has on average 357 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Porto Velho?
In Porto Velho, between 1940 and 2025, the highest apparent temperature reached 44.3 °C on 22 October 1999, and the lowest was 8.9 °C on 18 July 1975.
Compare Porto Velho with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Porto Velho