Guajará-Mirim climate — normals and trends
Guajará-Mirim (Brazil) has a tropical savanna climate (Aw) under the Köppen-Geiger classification. Its mean annual temperature is 25.6 °C and it receives 1,775 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 (26.7 °C on average) and the coldest is June (24.4 °C). Rainfall peaks in January.
Guajará-Mirim averages 0 frost days, 224 hot days (≥ 30 °C) and 222 rainy days per year.
Guajará-Mirim has warmed by +1.1 °C between 1940 and 2025, or +0.13 °C per decade. This trend is statistically significant.
The hottest day of the period reached 39.7 °C (on 21 September 2024) and the coldest 9.3 °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
Guajará-MirimRondônia
- coords
- -10.78°, -65.34°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
25.6°C
Average daily high
30.7°C
Average daily low
22.2°C
Annual rainfall
1,775mm
Sunshine / day
9.4h
Mean relative humidity
84%
Average peak wind
9.4km/h
Seasonal range
2.3°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
224 d/yr
Rainy days (≥ 1 mm)
222 d/yr
Annual snowfall
0.0 cm
Average feels-like high
36.3 °C
Average feels-like low
25.9 °C
Average peak gust
27.0 km/h
Tropical nights (≥ 20 °C)
324 d/yr
Solar radiation
17.6 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.1 °C
since 1940
+0.1 °C per decade · r² = 0.44 · 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
39.7 °C
21 September 2024
Coldest day
9.3 °C
19 July 1975
Wettest day
194 mm
26 December 2020
Windiest day
27.7 km/h
25 June 1994
Strongest gust
62.6 km/h
17 December 1989
Hottest feels-like
45.6 °C
19 October 2023
Coldest feels-like
6.1 °C
19 July 1975
Sunniest day
12.6 h
29 December 2025
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 | +0.3 °C | 255 mm | -4 mm |
| Feb | 30.7 °C | +0.9 °C | 203 mm | -49 mm |
| Mar | 30.3 °C | +0.4 °C | 403 mm | +158 mm |
| Apr | 30.5 °C | +0.8 °C | 264 mm | +100 mm |
| May | 30.9 °C | +1.6 °C | 104 mm | +18 mm |
| Jun | 30.0 °C | +0.4 °C | 30 mm | -5 mm |
| Jul | 32.3 °C | +1.4 °C | 4 mm | -16 mm |
| Aug | 33.7 °C | +1.0 °C | 20 mm | -18 mm |
| Sep | 34.1 °C | +1.2 °C | 101 mm | +20 mm |
| Oct | 32.6 °C | +0.5 °C | 130 mm | -18 mm |
| Nov | 31.6 °C | +0.7 °C | 208 mm | +11 mm |
| Dec | 29.6 °C | -0.6 °C | 309 mm | +60 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 Guajará-Mirim?
Guajará-Mirim has a tropical savanna climate (Köppen Aw). Over 1940-2025, the average annual temperature is 25.6 °C and it receives 1,775 mm of precipitation per year.
What is the hottest day ever recorded in Guajará-Mirim?
The hottest day measured in Guajará-Mirim between 1940 and 2025 was 21 September 2024, reaching 39.7 °C.
What is the coldest day in Guajará-Mirim?
The coldest day measured in Guajará-Mirim between 1940 and 2025 was 19 July 1975, at 9.3 °C.
Does it snow in Guajará-Mirim?
Almost never: Guajará-Mirim sees virtually no snow, with about 0 frost days per year.
Has the climate of Guajará-Mirim warmed?
Yes: Guajará-Mirim warmed by +1.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Guajará-Mirim?
The wettest day measured in Guajará-Mirim between 1940 and 2025 was 26 December 2020, with 194 mm of rain in 24 hours.
What was the windiest day in Guajará-Mirim?
The windiest day measured in Guajará-Mirim between 1940 and 2025 was 25 June 1994, with winds reaching 27.7 km/h.
What is the warmest month in Guajará-Mirim?
The warmest month in Guajará-Mirim is September (26.7 °C on average); the coldest is June (24.4 °C).
How much does it rain in Guajará-Mirim?
Guajará-Mirim receives on average 1,775 mm of precipitation per year, spread over about 222 rainy days.
Is it sunny in Guajará-Mirim?
Guajará-Mirim gets on average 9.4 hours of sunshine per day, roughly 3,431 hours per year over 1940-2025.
Are there tropical nights in Guajará-Mirim?
Yes: Guajará-Mirim has on average 324 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Guajará-Mirim?
In Guajará-Mirim, between 1940 and 2025, the highest apparent temperature reached 45.6 °C on 19 October 2023, and the lowest was 6.1 °C on 19 July 1975.
Compare Guajará-Mirim with another city
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Nearby cities
The climate around Guajará-Mirim