March is one of the cooler months of the year in Decatur, with average highs near 17.8°C and lows around 5.3°C (mean 11.6°C). It is a relatively wet time of year, averaging 122 mm of rainfall and 81% 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 16.3°C — while the coldest was 2013 at 8°C. Typical March days reach 17.8°C with nights near 5.3°C. The long-term trend is warming, about 0.5°C per decade.
March is a relatively wet time of year in Decatur, averaging 122 mm of rainfall. The wettest March on record was 2001 with 254 mm, while the driest was 2004 at 26 mm.
Relative humidity in Decatur during March averages 81%. The most humid March was 2020 at 88%, and the least humid was 1981 at 76%.
March receives about 4.4 kWh/m²/day of solar energy in Decatur. The sunniest Marchs were 1986 and 2004 at 5.1 kWh/m²/day, and the cloudiest was 2020 at 3.6.
Average wind speed in Decatur during March is 1.5 m/s. The windiest Marchs were 2008, 2013 and 2018, among others at 1.7 m/s, while the calmest was 2007 at 1.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 10.8°C | 10.8°C | 11.9°C | 11.6°C | 13.2°C | +2.4°C |
| Avg High | 17.2°C | 16.9°C | 18.3°C | 17.7°C | 19.6°C | +2.4°C |
| Avg Low | 4.5°C | 4.7°C | 5.6°C | 5.5°C | 6.9°C | +2.4°C |
| Avg Rain | 101 mm | 139 mm | 133 mm | 102 mm | 137 mm | +37 mm |
March temperatures in Decatur have risen by about 2.3°C between 1981–1985 and 2021–2025.
March has ranged from a record low of -13.3°C (1993) to a record high of 28.7°C (2007).
Rainfall in March is a relatively wet time of year, averaging 122 mm, with a wettest year of 254 mm.
A quieter season to visit Decatur
If your dates are flexible, the more temperate months of May and September tend to be the most comfortable for visiting Decatur. That said, March — with days averaging 17.8°C and nights around 5.3°C (mean 11.6°C) and higher rainfall (122 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 | 19.7°C | 12.7°C | 5.6°C | 24.6°C | -0.5°C | 76 mm | 76% | 1.6 m/s | 4.9 |
| 2024 | 19.3°C | 13.1°C | 6.9°C | 24.9°C | -2.8°C | 176 mm | 81% | 1.5 m/s | 4.3 |
| 2023 | 19.0°C | 12.5°C | 6.1°C | 26.0°C | -5.1°C | 152 mm | 79% | 1.4 m/s | 4.7 |
| 2022 | 19.5°C | 12.7°C | 5.9°C | 25.5°C | -6.5°C | 139 mm | 77% | 1.6 m/s | 4.9 |
| 2021 | 19.5°C | 13.3°C | 7.1°C | 26.9°C | -1.5°C | 126 mm | 81% | 1.5 m/s | 4 |
| 2020 | 20.5°C | 15.1°C | 9.7°C | 27.5°C | -1.9°C | 155 mm | 88% | 1.4 m/s | 3.6 |
| 2019 | 16.9°C | 10.9°C | 4.8°C | 22.6°C | -4.8°C | 64 mm | 79% | 1.5 m/s | 4.6 |
| 2018 | 16.8°C | 10.4°C | 4.1°C | 23.7°C | -4.1°C | 115 mm | 78% | 1.7 m/s | 4.3 |
| 2017 | 18.4°C | 12.1°C | 5.7°C | 26.8°C | -5.7°C | 69 mm | 78% | 1.6 m/s | 4.8 |
| 2016 | 20.0°C | 13.9°C | 7.9°C | 26.4°C | 0.6°C | 92 mm | 83% | 1.5 m/s | 4.7 |
| 2015 | 19.1°C | 13.0°C | 6.9°C | 24.8°C | -4.5°C | 85 mm | 82% | 1.4 m/s | 3.8 |
| 2014 | 16.4°C | 9.7°C | 3.1°C | 24.3°C | -4.7°C | 101 mm | 80% | 1.5 m/s | 4.5 |
| 2013 ❄️ | 14.1°C | 8.0°C | 1.9°C | 21.2°C | -3.9°C | 116 mm | 80% | 1.7 m/s | 4.5 |
| 2012 🔥 | 21.9°C | 16.3°C | 10.7°C | 27.5°C | -1.4°C | 93 mm | 82% | 1.4 m/s | 4.6 |
| 2011 | 18.4°C | 12.4°C | 6.4°C | 26.5°C | -0.5°C | 164 mm | 83% | 1.6 m/s | 4.1 |
| 2010 | 14.7°C | 9.1°C | 3.4°C | 22.6°C | -3.7°C | 119 mm | 84% | 1.5 m/s | 4 |
| 2009 | 17.8°C | 12.0°C | 6.1°C | 25.3°C | -8.3°C | 203 mm | 83% | 1.4 m/s | 4 |
| 2008 | 18.1°C | 11.1°C | 4.1°C | 23.2°C | -4.1°C | 105 mm | 79% | 1.7 m/s | 4.7 |
| 2007 | 20.5°C | 14.0°C | 7.5°C | 28.7°C | -4.2°C | 63 mm | 77% | 1.3 m/s | 4.9 |
| 2006 | 18.0°C | 11.5°C | 5.0°C | 26.1°C | -2.7°C | 68 mm | 77% | 1.5 m/s | 4.8 |
| 2005 | 16.4°C | 10.2°C | 4.0°C | 25.5°C | -5.1°C | 183 mm | 80% | 1.6 m/s | 4.3 |
| 2004 | 19.8°C | 13.2°C | 6.7°C | 26.3°C | -3.1°C | 26 mm | 76% | 1.5 m/s | 5.1 |
| 2003 | 18.3°C | 13.0°C | 7.7°C | 23.0°C | -2.5°C | 162 mm | 85% | 1.4 m/s | 3.7 |
| 2002 | 19.0°C | 12.1°C | 5.2°C | 26.2°C | -5.3°C | 155 mm | 78% | 1.5 m/s | 4.5 |
| 2001 🌧️ | 14.8°C | 9.1°C | 3.5°C | 20.8°C | -3.3°C | 254 mm | 81% | 1.6 m/s | 4.2 |
| 2000 | 19.9°C | 13.1°C | 6.3°C | 24.5°C | -2.2°C | 106 mm | 78% | 1.4 m/s | 4.6 |
| 1999 | 16.5°C | 9.5°C | 2.5°C | 22.3°C | -3.9°C | 92 mm | 76% | 1.6 m/s | 4.7 |
| 1998 | 15.3°C | 9.8°C | 4.2°C | 25.7°C | -5.3°C | 161 mm | 84% | 1.7 m/s | 4.2 |
| 1997 | 20.3°C | 13.7°C | 7.2°C | 25.0°C | -2.4°C | 48 mm | 81% | 1.5 m/s | 4.8 |
| 1996 | 13.9°C | 8.2°C | 2.5°C | 20.9°C | -7.5°C | 201 mm | 81% | 1.7 m/s | 4.1 |
| 1995 | 18.4°C | 12.4°C | 6.5°C | 26.6°C | -3.5°C | 66 mm | 83% | 1.4 m/s | 4.2 |
| 1994 | 18.0°C | 11.3°C | 4.7°C | 25.4°C | -3.3°C | 166 mm | 81% | 1.7 m/s | 4.6 |
| 1993 | 14.0°C | 8.6°C | 3.1°C | 25.2°C | -13.3°C | 171 mm | 85% | 1.6 m/s | 3.9 |
| 1992 | 17.0°C | 10.4°C | 3.8°C | 23.8°C | -4.5°C | 112 mm | 79% | 1.5 m/s | 4.6 |
| 1991 | 17.7°C | 11.7°C | 5.6°C | 24.8°C | -1.2°C | 165 mm | 82% | 1.7 m/s | 4.2 |
| 1990 | 18.3°C | 12.6°C | 6.9°C | 25.5°C | -3.2°C | 211 mm | 85% | 1.5 m/s | 4.3 |
| 1989 | 18.4°C | 12.4°C | 6.4°C | 25.5°C | -2.7°C | 112 mm | 83% | 1.5 m/s | 3.8 |
| 1988 | 17.1°C | 10.4°C | 3.7°C | 24.1°C | -5.9°C | 62 mm | 80% | 1.5 m/s | 4.5 |
| 1987 | 16.4°C | 10.7°C | 5.0°C | 23.6°C | -1.9°C | 104 mm | 84% | 1.5 m/s | 4.3 |
| 1986 | 18.0°C | 11.0°C | 4.0°C | 25.9°C | -5.6°C | 102 mm | 76% | 1.5 m/s | 5.1 |
| 1985 | 18.2°C | 11.6°C | 5.1°C | 25.6°C | -3.6°C | 40 mm | 80% | 1.5 m/s | 4.5 |
| 1984 | 16.6°C | 10.1°C | 3.6°C | 24.1°C | -5.1°C | 127 mm | 82% | 1.6 m/s | 4.5 |
| 1983 | 15.5°C | 9.8°C | 4.1°C | 23.3°C | -4.1°C | 181 mm | 83% | 1.7 m/s | — |
| 1982 | 18.3°C | 12.5°C | 6.7°C | 26.8°C | -4.5°C | 70 mm | 84% | 1.4 m/s | — |
| 1981 | 15.9°C | 9.0°C | 2.2°C | 24.2°C | -3.9°C | 109 mm | 76% | 1.6 m/s | — |
Actual recorded March data for each year, 1981–2025 — sourced from NASA POWER.
The average high in March is around 17.8°C with lows near 5.3°C (mean 11.6°C), based on 45 years of NASA POWER data.
March averages 122 mm of rainfall in Decatur, a relatively wet time of year. The wettest on record was 254 mm in 2001.
The hottest March reached 28.7°C in 2007. The coldest dipped to -13.3°C in 1993.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average March temperatures have risen by about 2.3°C. Daytime highs moved from 16.9°C to 19.4°C and overnight lows from 4.3°C to 6.3°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 17.8°C daytime highs and 5.3°C at night.
Not quite — March is the 5th coolest month in Decatur, averaging 11.6°C.
For March in Decatur, pack warm layers and a jacket for chilly mornings, with typical highs of 17.8°C and lows of 5.3°C. Bring an umbrella or light rain jacket too.
Relative humidity in March averages 81% — quite humid.
Average wind speed in March is 1.5 m/s. The windiest March on record averaged 1.7 m/s (1983).
The wettest March on record was 2001 with 254 mm. On average, March sees 122 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.
