Marshalltown weather in September: Marshalltown, Iowa: normal highs, lows, rain and records for September
Marshalltown in September has a normal high of 75°F and a normal low of 51°F, a daily mean of 63°F, falling from 79°F on the 1st to 70°F by the 30th. Measurable precipitation falls on 10 days in a normal September, 3.20 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 24°C and low of 10°C, 81 mm of precipitation in September.
- NOAA stationMarshalltown Municipal Airport
- Station IDUSW00094988
- Location42.11°N 92.92°W
- Elevation974 ft (297 m)
- From the center5 miles
- Population27,886
- Jan 28° 10°
- Feb 32° 14°
- Mar 46° 26°
- Apr 60° 37°
- May 71° 49°
- Jun 81° 59°
- Jul 83° 62°
- Aug 81° 60°
- Sep 75° 51°
- Oct 62° 39°
- Nov 46° 26°
- Dec 33° 16°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Marshalltown in September?
The normal high is 75°F and the normal low 51°F, for a daily mean of 62.8°F. September is 7.4°F cooler than August and 12.6°F warmer than October. September is the 4th warmest month of the year in Marshalltown and the 6th wettest. Across the month the normal high falls 9°F, from 79°F on September 1 to 70°F on September 30. From one year to the next September's mean temperature typically moves about 3.2°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 60°F and 66°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 37%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 79°F | 56°F | 37% | 19% |
| September 8 | 78°F | 53°F | 35% | 19% |
| September 15 | 76°F | 51°F | 33% | 19% |
| September 22 | 73°F | 48°F | 31% | 19% |
| September 30 | 70°F | 45°F | 31% | 19% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 79°F | 56°F | 37% | 19% | 13 h 10 min |
| September 2 | 79°F | 55°F | 37% | 19% | 13 h 10 min |
| September 3 | 79°F | 55°F | 36% | 19% | 13 h 10 min |
| September 4 | 78°F | 55°F | 36% | 19% | 13 h |
| September 5 | 78°F | 54°F | 36% | 19% | 13 h |
| September 6 | 78°F | 54°F | 35% | 19% | 13 h |
| September 7 | 78°F | 54°F | 35% | 19% | 13 h |
| September 8 | 78°F | 53°F | 35% | 19% | 12 h 50 min |
| September 9 | 77°F | 53°F | 35% | 20% | 12 h 50 min |
| September 10 | 77°F | 53°F | 34% | 20% | 12 h 50 min |
| September 11 | 77°F | 52°F | 34% | 20% | 12 h 40 min |
| September 12 | 77°F | 52°F | 34% | 20% | 12 h 40 min |
| September 13 | 76°F | 52°F | 33% | 19% | 12 h 40 min |
| September 14 | 76°F | 51°F | 33% | 19% | 12 h 40 min |
| September 15 | 76°F | 51°F | 33% | 19% | 12 h 30 min |
| September 16 | 75°F | 51°F | 32% | 19% | 12 h 30 min |
| September 17 | 75°F | 50°F | 32% | 19% | 12 h 30 min |
| September 18 | 75°F | 50°F | 32% | 20% | 12 h 20 min |
| September 19 | 74°F | 49°F | 32% | 20% | 12 h 20 min |
| September 20 | 74°F | 49°F | 32% | 20% | 12 h 20 min |
| September 21 | 74°F | 49°F | 32% | 20% | 12 h 20 min |
| September 22 | 73°F | 48°F | 31% | 19% | 12 h 10 min |
| September 23 | 73°F | 48°F | 31% | 19% | 12 h 10 min |
| September 24 | 73°F | 48°F | 31% | 19% | 12 h 10 min |
| September 25 | 72°F | 47°F | 31% | 19% | 12 h 10 min |
| September 26 | 72°F | 47°F | 31% | 19% | 12 h |
| September 27 | 71°F | 46°F | 31% | 19% | 12 h |
| September 28 | 71°F | 46°F | 31% | 19% | 12 h |
| September 29 | 70°F | 46°F | 31% | 19% | 11 h 50 min |
| September 30 | 70°F | 45°F | 31% | 19% | 11 h 50 min |
- Normal high
- 75°FSeptember average
- Normal low
- 51°FSeptember average
- Precipitation
- 3.20 inmonth total
- Days with precipitation
- 100.01 inch or more
- Days at 90°F or more
- 2
- Nights at 32°F or colder
- 1
- Daylight
- 13 h 10 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 23
- Days at 80°F or more
- 11
- Sunshine
- 79%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00094988; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Marshalltown in September?
On a given September day the chance of 0.01 inch or more is 33% on average, highest around September 1 (37%). In all, 3.20 in falls on 10 days of a normal September, 1 of them with an inch or more.
In a normal September in Marshalltown, 2 days reach 90°F and 1 nights fall to freezing.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00094988.
What are the records for September in Marshalltown?
The warmest September temperature on this station's record (since 1996) is 100°F, on September 9, 2013; the coldest is 27°F, on September 23, 2012. The wettest September brought 9.66 in (2018).
The September mean against the 1991-2020 normal of 62.8°F: 2021 66.7°F (+3.9), 2022 64.5°F (+1.8), 2023 68.0°F (+5.2), 2024 67.5°F (+4.8), 2025 66.9°F (+4.1), 2026 67.8°F (+5.0). 6 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 66.7°F | +3.9°F | 0.73 in |
| 2022 | 64.5°F | +1.8°F | 1.20 in |
| 2023 | 68.0°F | +5.2°F | 1.35 in |
| 2024 | 67.5°F | +4.8°F | 0.81 in |
| 2025 | 66.9°F | +4.1°F | 2.27 in |
| 2026 | 67.8°F | +5.0°F | 7.47 in |
Source: records: ACIS, station USW00094988; recent months: ACIS, station USW00094988. Records and recent months use complete months only.
How does September in Marshalltown compare across Iowa?
Across the 132 places PlainClimate covers in Iowa, September normal highs run from 71°F in Northwood to 79°F in Glenwood; Marshalltown's is 75°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.