December is one of the warmer months of the year in Seymour, with average highs near 27.4°C and lows around 11.3°C (mean 19.4°C). It is about average for rainfall, averaging 49 mm of rainfall and 57% relative humidity across the period.
December is one of the warmer months of the year in Seymour. Across 45 years of records, the warmest December in Seymour was 2015 — when the month averaged 22.8°C — while the coldest was 1995 at 16.6°C. Typical December days reach 27.4°C with nights near 11.3°C. The long-term trend is warming, about 0.4°C per decade.
December is about average for rainfall in Seymour, averaging 49 mm of rainfall. The wettest December on record was 1985 with 123 mm, while the driest was 1997 at 6 mm.
Relative humidity in Seymour during December averages 57%. The most humid December was 1992 at 77%, and the least humid was 2015 at 41%.
December receives about 7 kWh/m²/day of solar energy in Seymour. The sunniest December was 1994 at 8 kWh/m²/day, and the cloudiest was 1992 at 6.
Average wind speed in Seymour during December is 3 m/s. The windiest December was 2002 at 3.7 m/s, while the calmest was 1992 at 2.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 18.6°C | 19.0°C | 19.5°C | 20.3°C | 19.5°C | +0.9°C |
| Avg High | 26.4°C | 27.0°C | 27.7°C | 28.3°C | 27.4°C | +1°C |
| Avg Low | 10.7°C | 11.0°C | 11.3°C | 12.2°C | 11.5°C | +0.8°C |
| Avg Rain | 50 mm | 53 mm | 47 mm | 51 mm | 43 mm | -7 mm |
December temperatures in Seymour have risen by about 1°C between 1981–1985 and 2021–2025.
December has ranged from a record low of 3.5°C (2013) to a record high of 44.4°C (2019).
Rainfall in December is about average for rainfall, averaging 49 mm, with a wettest year of 123 mm.
One of the best times to visit Seymour
December is one of the best times to visit Seymour. Expect days averaging 27.4°C and nights around 11.3°C (mean 19.4°C) — warmer than Seymour's yearly average — with moderate rainfall (49 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 | 27.8°C | 19.5°C | 11.2°C | 39.2°C | 5.7°C | 38 mm | 53% | 3 m/s | — |
| 2024 | 29.6°C | 21.2°C | 12.7°C | 40.0°C | 8.3°C | 31 mm | 54% | 2.9 m/s | 7.8 |
| 2023 | 27.7°C | 20.4°C | 13.1°C | 37.5°C | 9.4°C | 85 mm | 61% | 3 m/s | 6.4 |
| 2022 | 24.7°C | 17.6°C | 10.4°C | 35.7°C | 5.1°C | 47 mm | 68% | 2.6 m/s | 7.3 |
| 2021 | 27.9°C | 19.6°C | 11.3°C | 37.9°C | 6.9°C | 25 mm | 57% | 3.2 m/s | 7.6 |
| 2020 | 26.8°C | 18.5°C | 10.3°C | 35.3°C | 6.4°C | 33 mm | 55% | 3.3 m/s | 7.3 |
| 2019 | 30.4°C | 21.3°C | 12.2°C | 44.4°C | 6.2°C | 9 mm | 47% | 3.4 m/s | 7.5 |
| 2018 | 29.7°C | 21.7°C | 13.7°C | 39.9°C | 8.4°C | 75 mm | 59% | 2.8 m/s | 6.7 |
| 2017 | 27.5°C | 20.0°C | 12.5°C | 35.3°C | 8.4°C | 115 mm | 62% | 2.8 m/s | 7 |
| 2016 | 28.5°C | 20.3°C | 12.2°C | 35.6°C | 6.2°C | 45 mm | 56% | 2.9 m/s | 7.1 |
| 2015 🔥 | 31.7°C | 22.8°C | 13.8°C | 41.1°C | 6.5°C | 29 mm | 41% | 3.1 m/s | 7.8 |
| 2014 | 28.9°C | 20.5°C | 12.1°C | 35.9°C | 7.7°C | 25 mm | 53% | 3 m/s | 6.8 |
| 2013 | 28.2°C | 19.6°C | 11.0°C | 38.9°C | 3.5°C | 48 mm | 56% | 3 m/s | 6.9 |
| 2012 | 28.8°C | 20.5°C | 12.1°C | 39.1°C | 8.0°C | 21 mm | 50% | 3.3 m/s | 7.1 |
| 2011 | 26.8°C | 19.2°C | 11.6°C | 34.7°C | 4.4°C | 47 mm | 59% | 3 m/s | 7.4 |
| 2010 | 22.9°C | 16.8°C | 10.7°C | 35.1°C | 4.5°C | 96 mm | 75% | 2.6 m/s | 6.4 |
| 2009 | 28.3°C | 19.6°C | 10.8°C | 38.1°C | 6.2°C | 35 mm | 54% | 2.9 m/s | 7.4 |
| 2008 | 25.3°C | 17.9°C | 10.5°C | 31.9°C | 5.5°C | 69 mm | 60% | 2.9 m/s | 6.6 |
| 2007 | 28.6°C | 20.7°C | 12.8°C | 38.8°C | 6.0°C | 84 mm | 55% | 2.9 m/s | 7 |
| 2006 | 28.7°C | 19.8°C | 10.9°C | 41.9°C | 5.1°C | 19 mm | 44% | 3.4 m/s | 7.7 |
| 2005 | 28.8°C | 20.2°C | 11.6°C | 43.4°C | 7.0°C | 43 mm | 50% | 2.8 m/s | 7.2 |
| 2004 | 25.9°C | 18.6°C | 11.2°C | 35.8°C | 6.1°C | 67 mm | 62% | 2.8 m/s | 6.9 |
| 2003 | 29.2°C | 21.0°C | 12.7°C | 38.9°C | 7.6°C | 68 mm | 57% | 2.8 m/s | 7.2 |
| 2002 | 28.8°C | 20.3°C | 11.8°C | 40.5°C | 5.8°C | 41 mm | 50% | 3.7 m/s | 6.7 |
| 2001 | 25.2°C | 17.4°C | 9.6°C | 35.8°C | 5.7°C | 17 mm | 57% | 3.2 m/s | 6.4 |
| 2000 | 28.2°C | 19.6°C | 10.9°C | 37.1°C | 5.6°C | 24 mm | 55% | 3.1 m/s | 7.8 |
| 1999 | 26.3°C | 18.8°C | 11.3°C | 35.7°C | 5.7°C | 92 mm | 57% | 3.3 m/s | 6.7 |
| 1998 | 28.7°C | 19.9°C | 11.2°C | 40.1°C | 6.1°C | 29 mm | 56% | 3 m/s | 7.2 |
| 1997 | 29.4°C | 20.7°C | 12.0°C | 36.8°C | 7.8°C | 6 mm | 51% | 3.2 m/s | 7.5 |
| 1996 | 25.8°C | 17.6°C | 9.4°C | 36.0°C | 5.1°C | 31 mm | 56% | 3 m/s | 7.1 |
| 1995 ❄️ | 24.6°C | 16.6°C | 8.6°C | 32.3°C | 3.7°C | 33 mm | 61% | 3.4 m/s | 6.7 |
| 1994 | 31.7°C | 22.0°C | 12.4°C | 40.1°C | 4.4°C | 7 mm | 43% | 3.2 m/s | 8 |
| 1993 | 24.2°C | 16.9°C | 9.7°C | 32.2°C | 3.8°C | 97 mm | 67% | 3 m/s | 6.6 |
| 1992 | 23.3°C | 17.7°C | 12.1°C | 29.5°C | 4.8°C | 117 mm | 77% | 2.3 m/s | 6 |
| 1991 | 26.0°C | 18.3°C | 10.5°C | 35.5°C | 4.9°C | 94 mm | 60% | 2.8 m/s | 6.8 |
| 1990 | 29.9°C | 21.1°C | 12.3°C | 38.8°C | 6.1°C | 24 mm | 50% | 3.1 m/s | 6.9 |
| 1989 | 27.8°C | 19.5°C | 11.3°C | 36.7°C | 7.4°C | 31 mm | 56% | 3 m/s | 7.2 |
| 1988 | 26.5°C | 19.2°C | 11.9°C | 36.5°C | 6.0°C | 79 mm | 65% | 2.7 m/s | 6.6 |
| 1987 | 26.4°C | 18.2°C | 10.0°C | 36.9°C | 3.8°C | 69 mm | 58% | 3.2 m/s | 6.9 |
| 1986 | 24.3°C | 16.8°C | 9.2°C | 33.3°C | 4.6°C | 62 mm | 63% | 3 m/s | 6.5 |
| 1985 🌧️ | 23.5°C | 17.2°C | 10.9°C | 30.8°C | 6.9°C | 123 mm | 70% | 2.6 m/s | 6.1 |
| 1984 | 26.7°C | 18.2°C | 9.6°C | 36.2°C | 5.1°C | 22 mm | 52% | 3.3 m/s | 6.9 |
| 1983 | 26.4°C | 18.6°C | 10.8°C | 36.2°C | 6.0°C | 21 mm | 61% | 2.9 m/s | — |
| 1982 | 28.6°C | 20.3°C | 11.9°C | 36.2°C | 7.4°C | 31 mm | 48% | 3.2 m/s | — |
| 1981 | 27.3°C | 19.0°C | 10.8°C | 37.2°C | 7.1°C | 15 mm | 54% | 3.2 m/s | — |
Actual recorded December data for each year, 1981–2025 — sourced from NASA POWER.
The average high in December is around 27.4°C with lows near 11.3°C (mean 19.4°C), based on 45 years of NASA POWER data.
December averages 49 mm of rainfall in Seymour, about average for rainfall. The wettest on record was 123 mm in 1985.
The hottest December reached 44.4°C in 2019. The coldest dipped to 3.5°C in 2013.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average December temperatures have risen by about 1°C. Daytime highs moved from 26.5°C to 27.5°C and overnight lows from 10.8°C to 11.7°C over the same span.
December is one of the warmer months of the year in Seymour and about average for rainfall, so plan for around 27.4°C daytime highs and 11.3°C at night.
Not quite — December is the 10th coolest month in Seymour, averaging 19.4°C.
For December in Seymour, pack light layers you can adjust through the day, with typical highs of 27.4°C and lows of 11.3°C.
Relative humidity in December averages 57% — moderately humid.
Average wind speed in December is 3 m/s. The windiest December on record averaged 3.7 m/s (2002).
The wettest December on record was 1985 with 123 mm. On average, December sees 49 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 Seymour 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.
