December is one of the cooler months of the year in West Siang, with average highs near 20.5°C and lows around 8.8°C (mean 14.7°C). It is one of the drier months, averaging 12 mm of rainfall and 73% relative humidity across the period.
December is one of the cooler months of the year in West Siang. Across 45 years of records, the warmest December in West Siang was 2016 — when the month averaged 17.2°C — while the coldest was 1983 at 13.1°C. Typical December days reach 20.5°C with nights near 8.8°C. The long-term trend is warming, about 0.4°C per decade.
December is one of the drier months in West Siang, averaging 12 mm of rainfall. The wettest December on record was 1985 with 85 mm, while the driest were 1994, 1996 and 2005 at 0 mm.
Relative humidity in West Siang during December averages 73%. The most humid December was 2009 at 80%, and the least humid was 1998 at 61%.
December receives about 3.1 kWh/m²/day of solar energy in West Siang. The sunniest December was 2005 at 3.6 kWh/m²/day, and the cloudiest was 2009 at 2.4.
Average wind speed in West Siang during December is 0.5 m/s. The windiest Decembers were 2010, 2024 and 2025, among others at 0.6 m/s, while the calmest were 2015, 2019 and 2020, among others at 0.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 14.1°C | 14.3°C | 14.5°C | 15.4°C | 15.3°C | +1.2°C |
| Avg High | 20.1°C | 20.6°C | 20.6°C | 20.6°C | 20.5°C | +0.4°C |
| Avg Low | 8.0°C | 7.9°C | 8.5°C | 10.2°C | 10.0°C | +2°C |
| Avg Rain | 25 mm | 10 mm | 6 mm | 10 mm | 13 mm | -12 mm |
December temperatures in West Siang have risen by about 1.8°C between 1981–1985 and 2021–2025.
December has ranged from a record low of 3.9°C (1982) to a record high of 29.2°C (1998).
Rainfall in December is one of the drier months, averaging 12 mm, with a wettest year of 85 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.1°C per decade while lows rose 0.7°C per decade, narrowing the gap between day and night.
A good time to visit West Siang
December is a good time to visit West Siang, with days averaging 20.5°C and nights around 8.8°C (mean 14.7°C, cooler than West Siang's yearly average) and low rainfall. October and November are marginally more temperate, but December still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 21.1°C | 15.7°C | 10.2°C | 24.3°C | 8.2°C | 4 mm | 72% | 0.6 m/s | — |
| 2024 | 20.2°C | 14.7°C | 9.2°C | 23.4°C | 6.7°C | 2 mm | 72% | 0.6 m/s | 3 |
| 2023 | 21.6°C | 16.1°C | 10.7°C | 25.5°C | 7.9°C | 15 mm | 75% | 0.5 m/s | 3.1 |
| 2022 | 20.1°C | 15.0°C | 9.9°C | 24.8°C | 6.3°C | 29 mm | 78% | 0.5 m/s | 2.5 |
| 2021 | 20.7°C | 15.4°C | 10.1°C | 24.9°C | 6.0°C | 14 mm | 76% | 0.5 m/s | 3 |
| 2020 | 19.5°C | 14.8°C | 10.1°C | 23.3°C | 7.0°C | 12 mm | 79% | 0.4 m/s | 2.8 |
| 2019 | 19.4°C | 14.6°C | 9.9°C | 26.1°C | 5.5°C | 3 mm | 78% | 0.4 m/s | 2.8 |
| 2018 | 20.8°C | 15.5°C | 10.1°C | 23.5°C | 7.2°C | 19 mm | 74% | 0.5 m/s | 3.1 |
| 2017 | 21.8°C | 16.9°C | 11.9°C | 26.5°C | 8.7°C | 1 mm | 77% | 0.5 m/s | 3.3 |
| 2016 🔥 | 22.8°C | 17.2°C | 11.5°C | 28.3°C | 7.7°C | 7 mm | 73% | 0.5 m/s | 3.4 |
| 2015 | 19.4°C | 14.5°C | 9.7°C | 24.2°C | 5.5°C | 13 mm | 78% | 0.4 m/s | 2.6 |
| 2014 | 21.6°C | 16.5°C | 11.3°C | 25.8°C | 7.9°C | 2 mm | 77% | 0.4 m/s | 3 |
| 2013 | 18.7°C | 14.1°C | 9.5°C | 24.0°C | 5.4°C | 7 mm | 79% | 0.4 m/s | 2.8 |
| 2012 | 20.2°C | 15.5°C | 10.8°C | 23.8°C | 7.0°C | 15 mm | 79% | 0.4 m/s | 2.9 |
| 2011 | 20.4°C | 14.7°C | 9.0°C | 24.1°C | 5.7°C | 25 mm | 73% | 0.5 m/s | 2.8 |
| 2010 | 20.7°C | 14.4°C | 8.1°C | 26.2°C | 5.4°C | 5 mm | 71% | 0.6 m/s | 3.5 |
| 2009 | 18.1°C | 13.3°C | 8.6°C | 20.8°C | 5.4°C | 8 mm | 80% | 0.5 m/s | 2.4 |
| 2008 | 20.6°C | 15.1°C | 9.7°C | 24.1°C | 5.9°C | 2 mm | 77% | 0.5 m/s | 3 |
| 2007 | 20.4°C | 14.2°C | 8.1°C | 25.2°C | 5.8°C | 6 mm | 69% | 0.5 m/s | 3.2 |
| 2006 | 20.7°C | 14.8°C | 8.9°C | 26.0°C | 7.0°C | 12 mm | 72% | 0.5 m/s | 2.9 |
| 2005 | 21.8°C | 15.1°C | 8.5°C | 25.3°C | 6.9°C | 0 mm | 67% | 0.5 m/s | 3.6 |
| 2004 | 19.8°C | 13.9°C | 8.1°C | 24.7°C | 4.5°C | 15 mm | 73% | 0.5 m/s | 3.1 |
| 2003 | 20.8°C | 14.8°C | 8.7°C | 27.8°C | 6.1°C | 3 mm | 70% | 0.5 m/s | 3.1 |
| 2002 | 20.3°C | 14.4°C | 8.6°C | 28.4°C | 6.0°C | 2 mm | 71% | 0.5 m/s | 3.1 |
| 2001 | 21.8°C | 14.7°C | 7.6°C | 26.9°C | 5.4°C | 6 mm | 65% | 0.5 m/s | 3.1 |
| 2000 | 21.8°C | 14.8°C | 7.8°C | 26.6°C | 6.2°C | 2 mm | 62% | 0.5 m/s | 3.4 |
| 1999 | 21.3°C | 14.9°C | 8.6°C | 26.6°C | 5.4°C | 1 mm | 68% | 0.5 m/s | 3.2 |
| 1998 | 23.1°C | 15.7°C | 8.3°C | 29.2°C | 5.5°C | 4 mm | 61% | 0.5 m/s | 3.4 |
| 1997 | 19.6°C | 13.7°C | 7.9°C | 22.0°C | 5.0°C | 25 mm | 72% | 0.5 m/s | 2.8 |
| 1996 | 21.2°C | 14.2°C | 7.3°C | 23.6°C | 6.2°C | 0 mm | 67% | 0.5 m/s | 3.4 |
| 1995 | 19.4°C | 13.7°C | 8.0°C | 20.9°C | 5.8°C | 23 mm | 77% | 0.4 m/s | 2.7 |
| 1994 | 20.6°C | 13.7°C | 6.8°C | 25.9°C | 4.9°C | 0 mm | 65% | 0.5 m/s | 3.2 |
| 1993 | 21.7°C | 15.2°C | 8.7°C | 25.5°C | 6.4°C | 0 mm | 69% | 0.5 m/s | 3.1 |
| 1992 | 19.3°C | 13.2°C | 7.0°C | 22.0°C | 4.5°C | 3 mm | 68% | 0.6 m/s | 3.2 |
| 1991 | 19.6°C | 13.8°C | 8.0°C | 26.9°C | 4.6°C | 43 mm | 72% | 0.5 m/s | 3.1 |
| 1990 | 20.6°C | 14.6°C | 8.5°C | 24.1°C | 6.8°C | 0 mm | 73% | 0.5 m/s | 3.2 |
| 1989 | 19.8°C | 13.4°C | 6.9°C | 26.0°C | 4.9°C | 14 mm | 69% | 0.6 m/s | 3.2 |
| 1988 | 21.2°C | 15.5°C | 9.8°C | 26.3°C | 6.6°C | 10 mm | 74% | 0.5 m/s | 3.1 |
| 1987 | 22.3°C | 15.9°C | 9.5°C | 26.1°C | 7.1°C | 16 mm | 68% | 0.5 m/s | 3.4 |
| 1986 | 20.6°C | 14.1°C | 7.5°C | 27.5°C | 4.5°C | 12 mm | 70% | 0.5 m/s | 3.1 |
| 1985 🌧️ | 19.7°C | 13.8°C | 7.9°C | 24.5°C | 5.8°C | 85 mm | 75% | 0.5 m/s | 3.1 |
| 1984 | 19.4°C | 13.4°C | 7.3°C | 23.2°C | 5.2°C | 23 mm | 73% | 0.5 m/s | 2.9 |
| 1983 ❄️ | 19.1°C | 13.1°C | 7.2°C | 22.7°C | 5.1°C | 33 mm | 72% | 0.5 m/s | — |
| 1982 | 18.9°C | 13.3°C | 7.7°C | 22.3°C | 3.9°C | 9 mm | 74% | 0.5 m/s | — |
| 1981 | 20.0°C | 14.3°C | 8.5°C | 25.3°C | 5.7°C | 22 mm | 76% | 0.5 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 20.5°C with lows near 8.8°C (mean 14.7°C), based on 45 years of NASA POWER data.
December averages 12 mm of rainfall in West Siang, one of the drier months. The wettest on record was 85 mm in 1985.
The hottest December reached 29.2°C in 1998. The coldest dipped to 3.9°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 1.8°C. Daytime highs moved from 19.4°C to 20.7°C and overnight lows from 7.7°C to 10°C over the same span.
December is one of the cooler months of the year in West Siang and one of the drier months, so plan for around 20.5°C daytime highs and 8.8°C at night.
Not quite — December is the 2nd coolest month in West Siang, averaging 14.7°C.
For December in West Siang, pack light layers you can adjust through the day, with typical highs of 20.5°C and lows of 8.8°C.
Relative humidity in December averages 73% — moderately humid.
Average wind speed in December is 0.5 m/s. The windiest December on record averaged 0.6 m/s (1989).
The wettest December on record was 1985 with 85 mm. On average, December sees 12 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in West Siang behaves each December, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for December specifically, along with year-by-year records and how the month has changed over the decades.
