December is one of the warmer months of the year in Tumby Bay, with average highs near 21°C and lows around 16.5°C (mean 18.8°C). It is one of the drier months, averaging 20 mm of rainfall and 71% relative humidity across the period.
December is one of the warmer months of the year in Tumby Bay. Across 45 years of records, the warmest December in Tumby Bay was 2015 — when the month averaged 21.3°C — while the coldest was 2001 at 16.8°C. Typical December days reach 21°C with nights near 16.5°C. The long-term trend is warming, about 0.3°C per decade.
December is one of the drier months in Tumby Bay, averaging 20 mm of rainfall. The wettest December on record was 1992 with 85 mm, while the driest were 2017 and 2018 at 1 mm.
Relative humidity in Tumby Bay during December averages 71%. The most humid December was 1992 at 80%, and the least humid was 2015 at 65%.
December receives about 7.4 kWh/m²/day of solar energy in Tumby Bay. The sunniest December was 2009 at 8.1 kWh/m²/day, and the cloudiest was 1992 at 6.2.
Average wind speed in Tumby Bay during December is 5.4 m/s. The windiest Decembers were 1999, 2002 and 2020 at 6 m/s, while the calmest was 2015 at 4.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 18.5°C | 18.2°C | 18.9°C | 19.5°C | 18.8°C | +0.3°C |
| Avg High | 20.8°C | 20.3°C | 21.2°C | 21.8°C | 21.0°C | +0.2°C |
| Avg Low | 16.2°C | 16.1°C | 16.6°C | 17.1°C | 16.7°C | +0.5°C |
| Avg Rain | 15 mm | 28 mm | 19 mm | 15 mm | 20 mm | +5 mm |
December temperatures in Tumby Bay have risen by about 0.3°C between 1981–1985 and 2021–2025.
December has ranged from a record low of 12.4°C (1987) to a record high of 36.1°C (2005).
Rainfall in December is one of the drier months, averaging 20 mm, with a wettest year of 85 mm.
One of the best times to visit Tumby Bay
December is one of the best times to visit Tumby Bay. Expect days averaging 21°C and nights around 16.5°C (mean 18.8°C) — warmer than Tumby Bay's yearly average — with low rainfall (20 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 22.0°C | 19.3°C | 16.7°C | 31.2°C | 14.4°C | 38 mm | 67% | 5.5 m/s | — |
| 2024 | 22.7°C | 20.3°C | 17.9°C | 32.3°C | 16.0°C | 5 mm | 70% | 5.1 m/s | 7.8 |
| 2023 | 19.9°C | 18.2°C | 16.4°C | 23.8°C | 14.4°C | 7 mm | 74% | 5.9 m/s | 6.7 |
| 2022 | 20.7°C | 18.6°C | 16.4°C | 32.9°C | 14.0°C | 43 mm | 72% | 5.4 m/s | 7.7 |
| 2021 | 20.5°C | 18.5°C | 16.4°C | 32.0°C | 14.2°C | 2 mm | 72% | 5.5 m/s | 8 |
| 2020 | 20.4°C | 18.2°C | 16.1°C | 31.1°C | 14.3°C | 25 mm | 70% | 6 m/s | 7.6 |
| 2019 | 23.2°C | 20.4°C | 17.6°C | 36.1°C | 13.9°C | 3 mm | 68% | 5.2 m/s | 7.7 |
| 2018 | 22.0°C | 19.7°C | 17.4°C | 31.8°C | 14.3°C | 1 mm | 72% | 5.7 m/s | 7.1 |
| 2017 | 21.8°C | 19.5°C | 17.2°C | 33.6°C | 15.1°C | 1 mm | 69% | 5.1 m/s | 7.2 |
| 2016 | 21.8°C | 19.3°C | 16.7°C | 29.8°C | 14.6°C | 3 mm | 69% | 5.2 m/s | 7.3 |
| 2015 🔥 | 24.2°C | 21.3°C | 18.4°C | 33.1°C | 14.0°C | 32 mm | 65% | 4.7 m/s | 7.9 |
| 2014 | 20.5°C | 18.7°C | 16.9°C | 27.2°C | 15.6°C | 9 mm | 73% | 5.4 m/s | 7.4 |
| 2013 | 21.6°C | 19.2°C | 16.8°C | 34.0°C | 13.4°C | 12 mm | 69% | 5.3 m/s | 7.5 |
| 2012 | 21.3°C | 19.0°C | 16.7°C | 29.1°C | 14.7°C | 7 mm | 70% | 5 m/s | 7.8 |
| 2011 | 21.2°C | 19.3°C | 17.4°C | 27.2°C | 14.7°C | 35 mm | 73% | 5.3 m/s | 7.3 |
| 2010 | 20.7°C | 18.5°C | 16.3°C | 27.8°C | 14.3°C | 43 mm | 72% | 5.4 m/s | 7.1 |
| 2009 | 21.9°C | 19.5°C | 17.1°C | 32.3°C | 14.3°C | 25 mm | 69% | 4.9 m/s | 8.1 |
| 2008 | 20.5°C | 18.4°C | 16.4°C | 26.5°C | 14.4°C | 46 mm | 74% | 5.2 m/s | 7.2 |
| 2007 | 22.7°C | 19.8°C | 16.9°C | 35.9°C | 14.1°C | 30 mm | 68% | 5.1 m/s | 7.4 |
| 2006 | 21.2°C | 18.8°C | 16.3°C | 33.3°C | 14.2°C | 11 mm | 69% | 5.7 m/s | 7.6 |
| 2005 | 22.5°C | 19.4°C | 16.3°C | 36.1°C | 14.6°C | 13 mm | 68% | 5.9 m/s | 7.5 |
| 2004 | 20.8°C | 18.8°C | 16.7°C | 28.9°C | 14.3°C | 8 mm | 73% | 5.5 m/s | 7.6 |
| 2003 | 21.1°C | 19.0°C | 16.9°C | 28.9°C | 14.7°C | 7 mm | 73% | 5.4 m/s | 7.6 |
| 2002 | 20.6°C | 18.4°C | 16.2°C | 28.6°C | 13.3°C | 15 mm | 71% | 6 m/s | 7.3 |
| 2001 ❄️ | 18.5°C | 16.8°C | 15.1°C | 26.1°C | 13.8°C | 33 mm | 74% | 5.5 m/s | 7.1 |
| 2000 | 22.0°C | 20.0°C | 17.9°C | 29.1°C | 15.3°C | 4 mm | 70% | 5.5 m/s | 7.9 |
| 1999 | 20.6°C | 18.6°C | 16.6°C | 28.5°C | 14.1°C | 10 mm | 73% | 6 m/s | 7.3 |
| 1998 | 21.1°C | 18.9°C | 16.7°C | 32.4°C | 14.5°C | 12 mm | 71% | 5.2 m/s | 7.4 |
| 1997 | 20.5°C | 18.4°C | 16.4°C | 27.6°C | 15.1°C | 43 mm | 75% | 5.4 m/s | 7.6 |
| 1996 | 20.2°C | 18.0°C | 15.8°C | 30.6°C | 13.5°C | 14 mm | 70% | 5.3 m/s | 7.8 |
| 1995 | 19.2°C | 17.2°C | 15.2°C | 25.8°C | 13.0°C | 10 mm | 73% | 5.7 m/s | 7.2 |
| 1994 | 22.0°C | 19.3°C | 16.6°C | 31.1°C | 13.3°C | 15 mm | 67% | 4.8 m/s | 7.7 |
| 1993 | 20.2°C | 18.2°C | 16.2°C | 28.4°C | 13.9°C | 24 mm | 72% | 5.6 m/s | 7.3 |
| 1992 🌧️ | 19.5°C | 17.8°C | 16.1°C | 29.9°C | 14.5°C | 85 mm | 80% | 5.5 m/s | 6.2 |
| 1991 | 19.3°C | 17.4°C | 15.6°C | 25.5°C | 13.7°C | 2 mm | 74% | 5.6 m/s | 7.5 |
| 1990 | 20.5°C | 18.2°C | 15.9°C | 30.9°C | 13.3°C | 68 mm | 74% | 5.3 m/s | 7 |
| 1989 | 21.5°C | 19.1°C | 16.8°C | 30.5°C | 13.9°C | 10 mm | 69% | 5.3 m/s | 7.7 |
| 1988 | 20.5°C | 18.5°C | 16.4°C | 34.0°C | 14.0°C | 21 mm | 73% | 5.4 m/s | 7.2 |
| 1987 | 20.7°C | 18.4°C | 16.0°C | 30.4°C | 12.4°C | 18 mm | 70% | 5.5 m/s | 7.4 |
| 1986 | 19.1°C | 16.9°C | 14.8°C | 31.3°C | 12.5°C | 27 mm | 70% | 5.9 m/s | 7 |
| 1985 | 19.8°C | 17.6°C | 15.5°C | 30.3°C | 14.1°C | 17 mm | 70% | 5.7 m/s | 7.4 |
| 1984 | 21.7°C | 19.2°C | 16.6°C | 31.1°C | 14.1°C | 11 mm | 68% | 5.5 m/s | 7.2 |
| 1983 | 21.5°C | 19.2°C | 16.8°C | 32.0°C | 13.5°C | 21 mm | 70% | 4.8 m/s | — |
| 1982 | 21.2°C | 18.9°C | 16.5°C | 27.4°C | 13.7°C | 6 mm | 69% | 4.9 m/s | — |
| 1981 | 20.9°C | 18.5°C | 16.2°C | 34.2°C | 14.5°C | 5 mm | 69% | 5.3 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 21°C with lows near 16.5°C (mean 18.8°C), based on 45 years of NASA POWER data.
December averages 20 mm of rainfall in Tumby Bay, one of the drier months. The wettest on record was 85 mm in 1992.
The hottest December reached 36.1°C in 2005. The coldest dipped to 12.4°C in 1987.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 0.3°C. Daytime highs moved from 21°C to 21.2°C and overnight lows from 16.3°C to 16.8°C over the same span.
December is one of the warmer months of the year in Tumby Bay and one of the drier months, so plan for around 21°C daytime highs and 16.5°C at night.
Not quite — December is the 9th coolest month in Tumby Bay, averaging 18.8°C.
For December in Tumby Bay, pack light layers you can adjust through the day, with typical highs of 21°C and lows of 16.5°C.
Relative humidity in December averages 71% — moderately humid.
Average wind speed in December is 5.4 m/s. The windiest December on record averaged 6 m/s (1999).
The wettest December on record was 1992 with 85 mm. On average, December sees 20 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 Tumby Bay 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.
