Biak climate — normals and trends
Biak (Indonesia) has a tropical rainforest climate (Af) under the Köppen-Geiger classification. Its mean annual temperature is 26.8 °C and it receives 2,862 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 November (27.1 °C on average) and the coldest is July (26.6 °C). Rainfall peaks in June.
Biak averages 0 frost days, 0 hot days (≥ 30 °C) and 326 rainy days per year.
Biak has warmed by +0.9 °C between 1940 and 2025, or +0.10 °C per decade. This trend is statistically significant.
The hottest day of the period reached 30.2 °C (on 23 November 2025) and the coldest 23.7 °C (on 14 September 1956).
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
BiakSpecial Region of Papua
- coords
- -1.18°, 136.08°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
26.8°C
Average daily high
27.7°C
Average daily low
25.8°C
Annual rainfall
2,862mm
Sunshine / day
10.1h
Mean relative humidity
83%
Average peak wind
16.4km/h
Seasonal range
0.5°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
326 d/yr
Annual snowfall
0.0 cm
Average feels-like high
33.0 °C
Average feels-like low
29.8 °C
Average peak gust
26.2 km/h
Tropical nights (≥ 20 °C)
365 d/yr
Solar radiation
18.1 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+0.9 °C
since 1940
+0.1 °C per decade · r² = 0.76 · 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
30.2 °C
23 November 2025
Coldest day
23.7 °C
14 September 1956
Wettest day
212 mm
6 April 2017
Windiest day
46.1 km/h
12 December 1964
Strongest gust
63.0 km/h
12 December 1964
Hottest feels-like
38.4 °C
15 October 2021
Coldest feels-like
25.8 °C
19 February 1942
Sunniest day
12.0 h
2 January 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 | 28.5 °C | +0.8 °C | 241 mm | +12 mm |
| Feb | 28.5 °C | +0.9 °C | 273 mm | +63 mm |
| Mar | 28.6 °C | +0.9 °C | 254 mm | +15 mm |
| Apr | 28.3 °C | +0.5 °C | 351 mm | +100 mm |
| May | 28.3 °C | +0.4 °C | 524 mm | +266 mm |
| Jun | 28.3 °C | +0.6 °C | 402 mm | +132 mm |
| Jul | 28.4 °C | +0.9 °C | 429 mm | +169 mm |
| Aug | 27.8 °C | +0.2 °C | 466 mm | +223 mm |
| Sep | 28.1 °C | +0.4 °C | 313 mm | +90 mm |
| Oct | 28.5 °C | +0.6 °C | 289 mm | +77 mm |
| Nov | 28.7 °C | +0.7 °C | 351 mm | +131 mm |
| Dec | 28.5 °C | +0.6 °C | 243 mm | -5 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 Biak?
Biak has a tropical rainforest climate (Köppen Af). Over 1940-2025, the average annual temperature is 26.8 °C and it receives 2,862 mm of precipitation per year.
What is the hottest day ever recorded in Biak?
The hottest day measured in Biak between 1940 and 2025 was 23 November 2025, reaching 30.2 °C.
What is the coldest day in Biak?
The coldest day measured in Biak between 1940 and 2025 was 14 September 1956, at 23.7 °C.
Does it snow in Biak?
Almost never: Biak sees virtually no snow, with about 0 frost days per year.
Has the climate of Biak warmed?
Yes: Biak warmed by +0.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Biak?
The wettest day measured in Biak between 1940 and 2025 was 6 April 2017, with 212 mm of rain in 24 hours.
What was the windiest day in Biak?
The windiest day measured in Biak between 1940 and 2025 was 12 December 1964, with winds reaching 46.1 km/h.
What is the warmest month in Biak?
The warmest month in Biak is November (27.1 °C on average); the coldest is July (26.6 °C).
How much does it rain in Biak?
Biak receives on average 2,862 mm of precipitation per year, spread over about 326 rainy days.
Is it sunny in Biak?
Biak gets on average 10.1 hours of sunshine per day, roughly 3,687 hours per year over 1940-2025.
Are there tropical nights in Biak?
Yes: Biak has on average 365 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Biak?
In Biak, between 1940 and 2025, the highest apparent temperature reached 38.4 °C on 15 October 2021, and the lowest was 25.8 °C on 19 February 1942.
Compare Biak with another city
Pick a second city: its normals will be set against these, indicator by indicator.