Decatur weather in March: Decatur, Illinois: normal highs, lows, rain and records for March
Decatur in March has a normal high of 52°F and a normal low of 32°F, a daily mean of 42°F, rising from 45°F on the 1st to 58°F by the 31st. Measurable precipitation falls on 11 days in a normal March, 2.51 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 11°C and low of 0°C, 64 mm of precipitation in March.
- NOAA stationDecatur Airport
- Station IDUSW00003887
- Location39.83°N 88.87°W
- Elevation675 ft (206 m)
- From the center4 miles
- Population68,763
- Jan 35° 20°
- Feb 40° 23°
- Mar 52° 32°
- Apr 64° 42°
- May 74° 53°
- Jun 83° 62°
- Jul 86° 66°
- Aug 84° 63°
- Sep 79° 55°
- Oct 66° 44°
- Nov 51° 34°
- Dec 40° 25°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Decatur in March?
The normal high is 52°F and the normal low 32°F, for a daily mean of 42.1°F. March is 10.5°F warmer than February and 11.0°F cooler than April. March is the 9th warmest month of the year in Decatur and the 9th wettest. Across the month the normal high rises 13°F, from 45°F on March 1 to 58°F on March 31. From one year to the next March's mean temperature typically moves about 4.5°F either way (NOAA's standard deviation), so roughly two Marchs in three average between 38°F and 47°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 35%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| March 1 | 45°F | 28°F | 30% | 16% |
| March 8 | 49°F | 30°F | 32% | 17% |
| March 15 | 52°F | 32°F | 33% | 18% |
| March 22 | 55°F | 34°F | 34% | 20% |
| March 31 | 58°F | 37°F | 35% | 21% |
Every day of March: normal high, low and chance of precipitation (warmest afternoon March 31, coldest night March 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| March 1 | 45°F | 28°F | 30% | 16% | 11 h 20 min |
| March 2 | 46°F | 28°F | 30% | 16% | 11 h 20 min |
| March 3 | 46°F | 28°F | 30% | 16% | 11 h 20 min |
| March 4 | 47°F | 29°F | 30% | 16% | 11 h 20 min |
| March 5 | 47°F | 29°F | 31% | 16% | 11 h 30 min |
| March 6 | 48°F | 29°F | 31% | 17% | 11 h 30 min |
| March 7 | 48°F | 30°F | 31% | 17% | 11 h 30 min |
| March 8 | 49°F | 30°F | 32% | 17% | 11 h 30 min |
| March 9 | 49°F | 30°F | 32% | 17% | 11 h 40 min |
| March 10 | 49°F | 31°F | 32% | 17% | 11 h 40 min |
| March 11 | 50°F | 31°F | 32% | 18% | 11 h 40 min |
| March 12 | 50°F | 31°F | 33% | 18% | 11 h 40 min |
| March 13 | 51°F | 32°F | 33% | 18% | 11 h 50 min |
| March 14 | 51°F | 32°F | 33% | 18% | 11 h 50 min |
| March 15 | 52°F | 32°F | 33% | 18% | 11 h 50 min |
| March 16 | 52°F | 32°F | 33% | 18% | 12 h |
| March 17 | 52°F | 33°F | 33% | 19% | 12 h |
| March 18 | 53°F | 33°F | 34% | 19% | 12 h |
| March 19 | 53°F | 33°F | 34% | 19% | 12 h |
| March 20 | 54°F | 34°F | 34% | 19% | 12 h 10 min |
| March 21 | 54°F | 34°F | 34% | 19% | 12 h 10 min |
| March 22 | 55°F | 34°F | 34% | 20% | 12 h 10 min |
| March 23 | 55°F | 35°F | 34% | 20% | 12 h 10 min |
| March 24 | 55°F | 35°F | 34% | 20% | 12 h 20 min |
| March 25 | 56°F | 35°F | 35% | 20% | 12 h 20 min |
| March 26 | 56°F | 35°F | 35% | 20% | 12 h 20 min |
| March 27 | 57°F | 36°F | 35% | 21% | 12 h 20 min |
| March 28 | 57°F | 36°F | 35% | 21% | 12 h 30 min |
| March 29 | 57°F | 36°F | 35% | 21% | 12 h 30 min |
| March 30 | 58°F | 37°F | 35% | 21% | 12 h 30 min |
| March 31 | 58°F | 37°F | 35% | 21% | 12 h 30 min |
- Normal high
- 52°FMarch average
- Normal low
- 32°FMarch average
- Precipitation
- 2.51 inmonth total
- Days with precipitation
- 110.01 inch or more
- Nights at 32°F or colder
- 17
- Daylight
- 11 h 20 min to 12 h 30 minMarch 1 to March 31
- Days at 70°F or more
- 3
- Days at 80°F or more
- 1
- Sunshine
- 67%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00003887; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Decatur in March?
On a given March day the chance of 0.01 inch or more is 33% on average, highest around March 31 (35%). In all, 2.51 in falls on 11 days of a normal March.
In a normal March in Decatur, 17 nights fall to freezing and 1 days stay below freezing all day.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00003887.
How humid and windy is Decatur in March?
At 3 p.m. the normal temperature is 56°F with 51% relative humidity and a dew point of 38°F; at 6 a.m. it is 40°F with 81% humidity. The wind averages 11.8 mph, most often from the southwest in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 40°F | 35°F | 81% | 10.2 mph | 52% |
| 9 a.m. | 48°F | 37°F | 66% | 13.3 mph | 54% |
| noon | 54°F | 38°F | 55% | 14.1 mph | 47% |
| 3 p.m. | 56°F | 38°F | 51% | 14.3 mph | 48% |
| 6 p.m. | 53°F | 38°F | 57% | 12.4 mph | 52% |
| 9 p.m. | 47°F | 38°F | 70% | 10.4 mph | 59% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00003887. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for March in Decatur?
The warmest March temperature on this station's record (since 2000) is 88°F, on March 26, 2026; the coldest is −9°F, on March 6, 2015. The wettest March brought 7.66 in (2026).
The March mean against the 1991-2020 normal of 42.1°F: 2021 46.1°F (+4.0), 2022 43.3°F (+1.2), 2023 42.0°F (−0.1), 2024 48.1°F (+6.0), 2025 48.8°F (+6.7), 2026 49.1°F (+7.0). 5 of 6 ran warmer than normal.
| March | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 46.1°F | +4.0°F | 4.29 in |
| 2022 | 43.3°F | +1.2°F | 5.07 in |
| 2023 | 42.0°F | −0.1°F | 3.76 in |
| 2024 | 48.1°F | +6.0°F | 2.49 in |
| 2025 | 48.8°F | +6.7°F | 1.99 in |
| 2026 | 49.1°F | +7.0°F | 7.66 in |
Source: records: ACIS, station USW00003887; recent months: ACIS, station USW00003887. Records and recent months use complete months only.
How does March in Decatur compare across Illinois?
Across the 144 places PlainClimate covers in Illinois, March normal highs run from 44°F in Antioch to 61°F in Anna; Decatur's is 52°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.