Dumai climate — normals and trends
Dumai (Indonesia) has a tropical rainforest climate (Af) under the Köppen-Geiger classification. Its mean annual temperature is 26.7 °C and it receives 2,551 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 May (27.3 °C on average) and the coldest is December (26.1 °C). Rainfall peaks in November.
Dumai averages 0 frost days, 273 hot days (≥ 30 °C) and 293 rainy days per year.
Dumai has warmed by +2.1 °C between 1940 and 2025, or +0.25 °C per decade. This trend is statistically significant.
The hottest day of the period reached 36.7 °C (on 18 July 2025) and the coldest 20.3 °C (on 2 February 1946).
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
DumaiRiau
- coords
- 1.67°, 101.44°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
26.7°C
Average daily high
31.0°C
Average daily low
24.0°C
Annual rainfall
2,551mm
Sunshine / day
10.1h
Mean relative humidity
87%
Average peak wind
8.9km/h
Seasonal range
1.2°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
273 d/yr
Rainy days (≥ 1 mm)
293 d/yr
Annual snowfall
0.0 cm
Average feels-like high
37.6 °C
Average feels-like low
28.7 °C
Average peak gust
25.5 km/h
Tropical nights (≥ 20 °C)
365 d/yr
Solar radiation
18.5 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.1 °C
since 1940
+0.3 °C per decade · r² = 0.87 · 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
36.7 °C
18 July 2025
Coldest day
20.3 °C
2 February 1946
Wettest day
263 mm
12 December 1954
Windiest day
26.9 km/h
28 November 2025
Strongest gust
57.2 km/h
22 December 1999
Hottest feels-like
45.3 °C
13 April 2013
Coldest feels-like
22.2 °C
2 February 1946
Sunniest day
12.0 h
18 October 1940
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 | 261 mm | +79 mm |
| Feb | 31.4 °C | +0.6 °C | 128 mm | +5 mm |
| Mar | 31.5 °C | +0.2 °C | 282 mm | +88 mm |
| Apr | 31.8 °C | +0.3 °C | 456 mm | +231 mm |
| May | 32.7 °C | +1.0 °C | 176 mm | -25 mm |
| Jun | 33.0 °C | +1.3 °C | 81 mm | -51 mm |
| Jul | 33.4 °C | +2.1 °C | 79 mm | -63 mm |
| Aug | 32.5 °C | +1.3 °C | 163 mm | -25 mm |
| Sep | 31.4 °C | +0.4 °C | 233 mm | -11 mm |
| Oct | 31.7 °C | +0.8 °C | 207 mm | -81 mm |
| Nov | 31.3 °C | +1.0 °C | 275 mm | -55 mm |
| Dec | 30.0 °C | +0.1 °C | 642 mm | +338 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 Dumai?
Dumai has a tropical rainforest climate (Köppen Af). Over 1940-2025, the average annual temperature is 26.7 °C and it receives 2,551 mm of precipitation per year.
What is the hottest day ever recorded in Dumai?
The hottest day measured in Dumai between 1940 and 2025 was 18 July 2025, reaching 36.7 °C.
What is the coldest day in Dumai?
The coldest day measured in Dumai between 1940 and 2025 was 2 February 1946, at 20.3 °C.
Does it snow in Dumai?
Almost never: Dumai sees virtually no snow, with about 0 frost days per year.
Has the climate of Dumai warmed?
Yes: Dumai warmed by +2.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Dumai?
The wettest day measured in Dumai between 1940 and 2025 was 12 December 1954, with 263 mm of rain in 24 hours.
What was the windiest day in Dumai?
The windiest day measured in Dumai between 1940 and 2025 was 28 November 2025, with winds reaching 26.9 km/h.
What is the warmest month in Dumai?
The warmest month in Dumai is May (27.3 °C on average); the coldest is December (26.1 °C).
How much does it rain in Dumai?
Dumai receives on average 2,551 mm of precipitation per year, spread over about 293 rainy days.
Is it sunny in Dumai?
Dumai gets on average 10.1 hours of sunshine per day, roughly 3,687 hours per year over 1940-2025.
Are there tropical nights in Dumai?
Yes: Dumai has on average 365 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Dumai?
In Dumai, between 1940 and 2025, the highest apparent temperature reached 45.3 °C on 13 April 2013, and the lowest was 22.2 °C on 2 February 1946.
Compare Dumai with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Dumai