December is one of the warmer months of the year in Streaky Bay, with average highs near 25.6°C and lows around 15.7°C (mean 20.7°C). It is about average for rainfall, averaging 19 mm of rainfall and 60% relative humidity across the period.
December is one of the warmer months of the year in Streaky Bay. Across 45 years of records, the warmest December in Streaky Bay was 2019 — when the month averaged 23.4°C — while the coldest was 2001 at 18°C. Typical December days reach 25.6°C with nights near 15.7°C. The long-term trend is warming, about 0.3°C per decade.
December is about average for rainfall in Streaky Bay, averaging 19 mm of rainfall. The wettest December on record was 1992 with 93 mm, while the driest were 2016, 2017 and 2018 at 0 mm.
Relative humidity in Streaky Bay during December averages 60%. The most humid December was 1992 at 74%, and the least humid was 2019 at 54%.
December receives about 7.9 kWh/m²/day of solar energy in Streaky Bay. The sunniest December was 2009 at 8.6 kWh/m²/day, and the cloudiest was 1992 at 6.3.
Average wind speed in Streaky Bay during December is 4.6 m/s. The windiest Decembers were 1986, 1999 and 2020 at 5.2 m/s, while the calmest were 2008 and 2015 at 4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 20.4°C | 20.1°C | 20.7°C | 21.4°C | 20.8°C | +0.4°C |
| Avg High | 25.4°C | 24.8°C | 25.8°C | 26.6°C | 25.7°C | +0.3°C |
| Avg Low | 15.4°C | 15.3°C | 15.7°C | 16.3°C | 15.8°C | +0.4°C |
| Avg Rain | 16 mm | 30 mm | 21 mm | 13 mm | 8 mm | -8 mm |
December temperatures in Streaky Bay have risen by about 0.6°C between 1981–1985 and 2021–2025.
December has ranged from a record low of 11°C (1987) to a record high of 43.5°C (2019).
Rainfall in December is about average for rainfall, averaging 19 mm, with a wettest year of 93 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.4°C per decade while lows rose 0.2°C per decade, widening the gap between day and night.
One of the best times to visit Streaky Bay
December is one of the best times to visit Streaky Bay. Expect days averaging 25.6°C and nights around 15.7°C (mean 20.7°C) — warmer than Streaky Bay's yearly average — with low rainfall (19 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 | 27.1°C | 21.7°C | 16.2°C | 36.5°C | 12.5°C | 5 mm | 56% | 4.8 m/s | — |
| 2024 | 27.1°C | 22.1°C | 17.1°C | 36.8°C | 13.9°C | 6 mm | 59% | 4.5 m/s | 8.3 |
| 2023 | 24.2°C | 19.8°C | 15.3°C | 32.8°C | 13.0°C | 10 mm | 63% | 5 m/s | 7.6 |
| 2022 | 26.4°C | 21.1°C | 15.8°C | 38.0°C | 11.8°C | 10 mm | 58% | 4.6 m/s | 8.1 |
| 2021 | 25.1°C | 20.0°C | 14.9°C | 34.8°C | 11.7°C | 7 mm | 63% | 4.9 m/s | 8.2 |
| 2020 | 24.3°C | 19.8°C | 15.3°C | 34.1°C | 12.9°C | 12 mm | 61% | 5.2 m/s | 7.9 |
| 2019 🔥 | 29.1°C | 23.4°C | 17.8°C | 43.5°C | 12.9°C | 1 mm | 54% | 4.6 m/s | 8.3 |
| 2018 | 27.1°C | 21.9°C | 16.8°C | 38.3°C | 13.3°C | 0 mm | 58% | 4.8 m/s | 7.2 |
| 2017 | 26.0°C | 20.9°C | 15.9°C | 37.6°C | 12.6°C | 0 mm | 58% | 4.4 m/s | 7.9 |
| 2016 | 26.5°C | 21.4°C | 16.4°C | 35.5°C | 12.4°C | 0 mm | 58% | 4.4 m/s | 7.6 |
| 2015 | 28.6°C | 22.8°C | 17.0°C | 38.5°C | 12.1°C | 34 mm | 55% | 4 m/s | 8.1 |
| 2014 | 24.5°C | 20.0°C | 15.6°C | 32.7°C | 13.6°C | 12 mm | 64% | 4.5 m/s | 8.3 |
| 2013 | 26.4°C | 21.2°C | 16.0°C | 38.6°C | 12.5°C | 15 mm | 57% | 4.4 m/s | 7.9 |
| 2012 | 26.0°C | 20.8°C | 15.6°C | 34.7°C | 12.5°C | 6 mm | 58% | 4.4 m/s | 8.5 |
| 2011 | 26.9°C | 21.7°C | 16.6°C | 38.5°C | 11.9°C | 21 mm | 59% | 4.6 m/s | 7.9 |
| 2010 | 24.5°C | 20.1°C | 15.7°C | 37.7°C | 12.6°C | 39 mm | 65% | 4.4 m/s | 7.7 |
| 2009 | 26.5°C | 21.2°C | 15.9°C | 38.4°C | 12.6°C | 8 mm | 57% | 4.4 m/s | 8.6 |
| 2008 | 24.0°C | 19.7°C | 15.4°C | 31.9°C | 11.8°C | 76 mm | 67% | 4 m/s | 7.5 |
| 2007 | 26.4°C | 21.3°C | 16.1°C | 37.9°C | 13.5°C | 38 mm | 57% | 4.3 m/s | 7.7 |
| 2006 | 25.8°C | 20.7°C | 15.5°C | 38.0°C | 12.2°C | 9 mm | 57% | 4.9 m/s | 8.1 |
| 2005 | 25.9°C | 20.7°C | 15.5°C | 36.8°C | 11.8°C | 19 mm | 60% | 4.6 m/s | 8 |
| 2004 | 25.5°C | 20.5°C | 15.5°C | 37.3°C | 13.1°C | 5 mm | 61% | 4.8 m/s | 7.5 |
| 2003 | 27.4°C | 21.9°C | 16.5°C | 37.2°C | 12.5°C | 10 mm | 60% | 4.5 m/s | 8.1 |
| 2002 | 27.1°C | 21.3°C | 15.6°C | 38.8°C | 11.8°C | 13 mm | 56% | 5 m/s | 7.9 |
| 2001 ❄️ | 21.9°C | 18.0°C | 14.2°C | 32.9°C | 12.0°C | 30 mm | 67% | 4.7 m/s | 7.4 |
| 2000 | 27.0°C | 21.9°C | 16.8°C | 38.1°C | 13.3°C | 3 mm | 58% | 4.7 m/s | 8.1 |
| 1999 | 25.4°C | 20.6°C | 15.8°C | 35.4°C | 12.6°C | 8 mm | 59% | 5.2 m/s | 7.9 |
| 1998 | 26.0°C | 21.0°C | 16.0°C | 38.3°C | 12.5°C | 11 mm | 59% | 4.7 m/s | 8.2 |
| 1997 | 25.5°C | 20.5°C | 15.5°C | 32.8°C | 12.9°C | 62 mm | 65% | 4.4 m/s | 8 |
| 1996 | 24.4°C | 19.8°C | 15.2°C | 33.9°C | 12.7°C | 13 mm | 61% | 4.7 m/s | 7.9 |
| 1995 | 24.4°C | 19.7°C | 15.1°C | 33.8°C | 11.0°C | 9 mm | 60% | 4.8 m/s | 7.5 |
| 1994 | 27.5°C | 21.8°C | 16.0°C | 37.7°C | 11.3°C | 5 mm | 56% | 4.5 m/s | 8.1 |
| 1993 | 24.3°C | 19.8°C | 15.3°C | 33.9°C | 11.7°C | 23 mm | 62% | 4.7 m/s | 7.3 |
| 1992 🌧️ | 22.3°C | 18.6°C | 14.8°C | 34.2°C | 12.3°C | 93 mm | 74% | 4.9 m/s | 6.3 |
| 1991 | 23.3°C | 18.9°C | 14.5°C | 35.2°C | 11.9°C | 1 mm | 65% | 4.7 m/s | 8 |
| 1990 | 24.7°C | 19.9°C | 15.2°C | 35.6°C | 12.3°C | 76 mm | 65% | 4.6 m/s | 7.7 |
| 1989 | 26.6°C | 21.4°C | 16.3°C | 36.3°C | 12.8°C | 16 mm | 55% | 4.4 m/s | 8.1 |
| 1988 | 25.5°C | 20.7°C | 15.9°C | 36.2°C | 12.0°C | 18 mm | 63% | 5.1 m/s | 7.8 |
| 1987 | 25.8°C | 20.6°C | 15.4°C | 35.6°C | 11.0°C | 9 mm | 56% | 4.8 m/s | 7.7 |
| 1986 | 24.3°C | 19.3°C | 14.3°C | 37.2°C | 11.6°C | 21 mm | 60% | 5.2 m/s | 7.8 |
| 1985 | 22.8°C | 18.6°C | 14.4°C | 34.7°C | 12.2°C | 25 mm | 64% | 5 m/s | 7.9 |
| 1984 | 25.6°C | 20.8°C | 15.9°C | 36.0°C | 11.3°C | 12 mm | 58% | 4.3 m/s | 7.4 |
| 1983 | 27.0°C | 21.7°C | 16.3°C | 37.6°C | 12.0°C | 24 mm | 57% | 4.4 m/s | — |
| 1982 | 26.3°C | 21.0°C | 15.8°C | 35.8°C | 11.1°C | 19 mm | 57% | 4.1 m/s | — |
| 1981 | 24.4°C | 19.6°C | 14.7°C | 35.7°C | 12.1°C | 6 mm | 60% | 4.6 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 25.6°C with lows near 15.7°C (mean 20.7°C), based on 45 years of NASA POWER data.
December averages 19 mm of rainfall in Streaky Bay, about average for rainfall. The wettest on record was 93 mm in 1992.
The hottest December reached 43.5°C in 2019. The coldest dipped to 11°C in 1987.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 0.6°C. Daytime highs moved from 25.2°C to 26°C and overnight lows from 15.4°C to 15.9°C over the same span.
December is one of the warmer months of the year in Streaky Bay and about average for rainfall, so plan for around 25.6°C daytime highs and 15.7°C at night.
Not quite — December is the 9th coolest month in Streaky Bay, averaging 20.7°C.
For December in Streaky Bay, pack light layers you can adjust through the day, with typical highs of 25.6°C and lows of 15.7°C.
Relative humidity in December averages 60% — moderately humid.
Average wind speed in December is 4.6 m/s. The windiest December on record averaged 5.2 m/s (1986).
The wettest December on record was 1992 with 93 mm. On average, December sees 19 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 Streaky 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.
