March is one of the cooler months of the year in Decatur, with average highs near 16.5°C and lows around 4.8°C (mean 10.7°C). It is a relatively wet time of year, averaging 138 mm of rainfall and 82% relative humidity across the period.
March is one of the cooler months of the year in Decatur. Across 45 years of records, the warmest March in Decatur was 2012 — when the month averaged 15.8°C — while the coldest was 2013 at 7.2°C. Typical March days reach 16.5°C with nights near 4.8°C. The long-term trend is warming, about 0.5°C per decade.
March is a relatively wet time of year in Decatur, averaging 138 mm of rainfall. The wettest March on record was 2021 with 311 mm, while the driest was 2007 at 31 mm.
Relative humidity in Decatur during March averages 82%. The most humid March was 2020 at 88%, and the least humid was 1986 at 74%.
March receives about 4.2 kWh/m²/day of solar energy in Decatur. The sunniest March was 1986 at 5 kWh/m²/day, and the cloudiest was 2020 at 3.3.
Average wind speed in Decatur during March is 1.4 m/s. The windiest Marchs were 2008, 2018 and 2025, among others at 1.5 m/s, while the calmest were 2007, 2015 and 2024, among others at 1.2 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 10.1°C | 9.9°C | 10.9°C | 10.7°C | 12.3°C | +2.2°C |
| Avg High | 16.1°C | 15.6°C | 17.0°C | 16.4°C | 18.2°C | +2.1°C |
| Avg Low | 4.2°C | 4.1°C | 5.0°C | 5.0°C | 6.4°C | +2.2°C |
| Avg Rain | 109 mm | 162 mm | 111 mm | 128 mm | 205 mm | +96 mm |
March temperatures in Decatur have risen by about 2°C between 1981–1985 and 2021–2025.
March has ranged from a record low of -10.8°C (1996) to a record high of 27.8°C (2007).
Rainfall in March is a relatively wet time of year, averaging 138 mm, with a wettest year of 311 mm.
A quieter season to visit Decatur
If your dates are flexible, the more temperate months of September and May tend to be the most comfortable for visiting Decatur. That said, March — with days averaging 16.5°C and nights around 4.8°C (mean 10.7°C) and higher rainfall (138 mm) — can still be rewarding for travellers who don't mind the cooler conditions, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 18.5°C | 12.1°C | 5.7°C | 24.3°C | -2.9°C | 166 mm | 77% | 1.5 m/s | 4.6 |
| 2024 | 18.5°C | 12.5°C | 6.5°C | 25.0°C | -3.4°C | 155 mm | 81% | 1.2 m/s | 4.3 |
| 2023 | 17.2°C | 11.1°C | 5.0°C | 24.4°C | -5.4°C | 162 mm | 80% | 1.4 m/s | 4.6 |
| 2022 | 17.4°C | 11.1°C | 4.9°C | 24.2°C | -6.0°C | 197 mm | 81% | 1.4 m/s | 4.7 |
| 2021 🌧️ | 18.6°C | 12.7°C | 6.9°C | 24.1°C | -2.1°C | 311 mm | 83% | 1.3 m/s | 4 |
| 2020 | 18.9°C | 14.1°C | 9.3°C | 26.3°C | -2.4°C | 238 mm | 88% | 1.3 m/s | 3.3 |
| 2019 | 15.2°C | 9.5°C | 3.8°C | 23.2°C | -5.2°C | 98 mm | 80% | 1.4 m/s | 4.5 |
| 2018 | 15.6°C | 9.9°C | 4.2°C | 22.4°C | -3.0°C | 108 mm | 82% | 1.5 m/s | 4 |
| 2017 | 17.7°C | 11.6°C | 5.5°C | 26.4°C | -5.1°C | 132 mm | 78% | 1.4 m/s | 4.4 |
| 2016 | 18.0°C | 12.6°C | 7.2°C | 25.3°C | -1.1°C | 131 mm | 84% | 1.4 m/s | 4.5 |
| 2015 | 16.9°C | 11.2°C | 5.5°C | 23.7°C | -9.9°C | 134 mm | 84% | 1.2 m/s | 3.8 |
| 2014 | 15.3°C | 8.9°C | 2.5°C | 22.4°C | -6.0°C | 72 mm | 81% | 1.3 m/s | 4.3 |
| 2013 ❄️ | 13.0°C | 7.2°C | 1.3°C | 20.9°C | -4.8°C | 135 mm | 81% | 1.4 m/s | 4 |
| 2012 🔥 | 21.2°C | 15.8°C | 10.4°C | 26.0°C | -0.5°C | 114 mm | 84% | 1.3 m/s | 4.7 |
| 2011 | 16.9°C | 11.3°C | 5.7°C | 25.4°C | -1.8°C | 236 mm | 84% | 1.3 m/s | 3.7 |
| 2010 | 13.8°C | 8.6°C | 3.4°C | 22.3°C | -4.1°C | 120 mm | 84% | 1.3 m/s | 3.8 |
| 2009 | 16.9°C | 11.4°C | 5.9°C | 24.4°C | -6.2°C | 137 mm | 83% | 1.4 m/s | 3.9 |
| 2008 | 17.2°C | 10.6°C | 4.0°C | 23.1°C | -3.0°C | 121 mm | 79% | 1.5 m/s | 4.5 |
| 2007 | 20.5°C | 14.2°C | 7.9°C | 27.8°C | -4.6°C | 31 mm | 77% | 1.2 m/s | 4.8 |
| 2006 | 16.6°C | 10.6°C | 4.6°C | 25.4°C | -3.5°C | 81 mm | 78% | 1.4 m/s | 4.6 |
| 2005 | 14.9°C | 9.1°C | 3.4°C | 24.3°C | -4.7°C | 92 mm | 82% | 1.3 m/s | 4.2 |
| 2004 | 18.2°C | 12.2°C | 6.3°C | 25.1°C | -2.3°C | 118 mm | 80% | 1.4 m/s | 4.8 |
| 2003 | 16.7°C | 11.3°C | 5.9°C | 22.7°C | -3.1°C | 76 mm | 84% | 1.2 m/s | 3.8 |
| 2002 | 16.5°C | 10.1°C | 3.8°C | 24.4°C | -7.4°C | 180 mm | 81% | 1.4 m/s | 4.1 |
| 2001 | 13.0°C | 7.5°C | 2.1°C | 18.3°C | -4.1°C | 149 mm | 83% | 1.3 m/s | 3.9 |
| 2000 | 19.0°C | 12.4°C | 5.8°C | 25.5°C | -2.5°C | 123 mm | 77% | 1.3 m/s | 4.4 |
| 1999 | 14.3°C | 8.0°C | 1.7°C | 19.9°C | -4.6°C | 129 mm | 80% | 1.4 m/s | 4.5 |
| 1998 | 14.5°C | 9.4°C | 4.4°C | 25.0°C | -5.9°C | 145 mm | 85% | 1.5 m/s | 3.7 |
| 1997 | 18.6°C | 12.5°C | 6.4°C | 24.0°C | -4.1°C | 129 mm | 82% | 1.4 m/s | 4.5 |
| 1996 | 13.4°C | 7.4°C | 1.5°C | 21.6°C | -10.8°C | 203 mm | 81% | 1.4 m/s | 4.3 |
| 1995 | 17.0°C | 11.1°C | 5.3°C | 24.8°C | -5.9°C | 108 mm | 83% | 1.4 m/s | 4.4 |
| 1994 | 16.1°C | 10.0°C | 4.0°C | 23.2°C | -3.1°C | 244 mm | 84% | 1.4 m/s | 4.2 |
| 1993 | 13.5°C | 8.2°C | 2.9°C | 24.5°C | -9.9°C | 155 mm | 84% | 1.4 m/s | 3.5 |
| 1992 | 16.0°C | 9.8°C | 3.6°C | 22.5°C | -6.0°C | 111 mm | 81% | 1.3 m/s | 4.3 |
| 1991 | 16.2°C | 10.6°C | 5.0°C | 23.5°C | -3.5°C | 200 mm | 85% | 1.5 m/s | 4 |
| 1990 | 16.8°C | 11.6°C | 6.3°C | 24.4°C | -4.5°C | 197 mm | 85% | 1.3 m/s | 3.8 |
| 1989 | 16.9°C | 11.2°C | 5.4°C | 23.8°C | -2.3°C | 157 mm | 86% | 1.4 m/s | 3.8 |
| 1988 | 16.1°C | 9.8°C | 3.5°C | 23.3°C | -5.8°C | 80 mm | 81% | 1.3 m/s | 4.4 |
| 1987 | 15.8°C | 10.4°C | 4.9°C | 23.5°C | -3.2°C | 106 mm | 83% | 1.3 m/s | 4.6 |
| 1986 | 17.4°C | 10.5°C | 3.6°C | 26.0°C | -6.3°C | 74 mm | 74% | 1.3 m/s | 5 |
| 1985 | 17.1°C | 11.4°C | 5.6°C | 24.9°C | -2.2°C | 71 mm | 82% | 1.4 m/s | 4.3 |
| 1984 | 15.3°C | 9.2°C | 3.1°C | 23.7°C | -5.5°C | 140 mm | 84% | 1.4 m/s | 4.1 |
| 1983 | 14.5°C | 9.2°C | 3.8°C | 21.8°C | -4.5°C | 136 mm | 84% | 1.4 m/s | — |
| 1982 | 16.8°C | 11.5°C | 6.2°C | 27.0°C | -5.6°C | 78 mm | 86% | 1.3 m/s | — |
| 1981 | 14.6°C | 8.1°C | 1.5°C | 24.4°C | -3.5°C | 141 mm | 76% | 1.3 m/s | — |
Actual recorded March data for each year, 1981–2025 — sourced from NASA POWER.
The average high in March is around 16.5°C with lows near 4.8°C (mean 10.7°C), based on 45 years of NASA POWER data.
March averages 138 mm of rainfall in Decatur, a relatively wet time of year. The wettest on record was 311 mm in 2021.
The hottest March reached 27.8°C in 2007. The coldest dipped to -10.8°C in 1996.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average March temperatures have risen by about 2°C. Daytime highs moved from 15.7°C to 18°C and overnight lows from 4°C to 5.8°C over the same span.
March is one of the cooler months of the year in Decatur and a relatively wet time of year, so plan for around 16.5°C daytime highs and 4.8°C at night.
Not quite — March is the 5th coolest month in Decatur, averaging 10.7°C.
For March in Decatur, pack warm layers and a jacket for chilly mornings, with typical highs of 16.5°C and lows of 4.8°C. Bring an umbrella or light rain jacket too.
Relative humidity in March averages 82% — quite humid.
Average wind speed in March is 1.4 m/s. The windiest March on record averaged 1.5 m/s (1991).
The wettest March on record was 2021 with 311 mm. On average, March sees 138 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 Decatur behaves each March, 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 March specifically, along with year-by-year records and how the month has changed over the decades.
