St. Joseph weather in September: St. Joseph, Missouri: normal highs, lows, rain and records for September
St. Joseph in September has a normal high of 80°F and a normal low of 54°F, a daily mean of 67°F, falling from 84°F on the 1st to 75°F by the 30th. Measurable precipitation falls on 8 days in a normal September, 3.18 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 27°C and low of 12°C, 81 mm of precipitation in September.
- NOAA stationSt Joseph Rosecrans Airport
- Station IDUSW00013993
- Location39.77°N 94.92°W
- Elevation818 ft (249 m)
- From the center6 miles
- Population71,098
- Jan 37° 17°
- Feb 43° 21°
- Mar 55° 32°
- Apr 66° 42°
- May 76° 54°
- Jun 85° 64°
- Jul 88° 67°
- Aug 86° 65°
- Sep 80° 54°
- Oct 68° 43°
- Nov 53° 31°
- Dec 41° 21°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is St. Joseph in September?
The normal high is 80°F and the normal low 54°F, for a daily mean of 67.0°F. September is 8.3°F cooler than August and 11.7°F warmer than October. September is the 4th warmest month of the year in St. Joseph and the 6th wettest. Across the month the normal high falls 9°F, from 84°F on September 1 to 75°F on September 30. From one year to the next September's mean temperature typically moves about 3.4°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 64°F and 70°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 31%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 84°F | 60°F | 31% | 17% |
| September 8 | 82°F | 57°F | 31% | 17% |
| September 15 | 80°F | 55°F | 30% | 17% |
| September 22 | 78°F | 52°F | 29% | 17% |
| September 30 | 75°F | 49°F | 28% | 17% |
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 | 84°F | 60°F | 31% | 17% | 13 h 10 min |
| September 2 | 83°F | 60°F | 31% | 17% | 13 h |
| September 3 | 83°F | 59°F | 31% | 17% | 13 h |
| September 4 | 83°F | 59°F | 31% | 17% | 13 h |
| September 5 | 83°F | 58°F | 31% | 17% | 13 h |
| September 6 | 83°F | 58°F | 31% | 17% | 12 h 50 min |
| September 7 | 82°F | 58°F | 31% | 17% | 12 h 50 min |
| September 8 | 82°F | 57°F | 31% | 17% | 12 h 50 min |
| September 9 | 82°F | 57°F | 31% | 17% | 12 h 50 min |
| September 10 | 82°F | 57°F | 31% | 17% | 12 h 40 min |
| September 11 | 81°F | 56°F | 30% | 17% | 12 h 40 min |
| September 12 | 81°F | 56°F | 30% | 17% | 12 h 40 min |
| September 13 | 81°F | 55°F | 30% | 17% | 12 h 40 min |
| September 14 | 80°F | 55°F | 30% | 17% | 12 h 30 min |
| September 15 | 80°F | 55°F | 30% | 17% | 12 h 30 min |
| September 16 | 80°F | 54°F | 30% | 17% | 12 h 30 min |
| September 17 | 80°F | 54°F | 30% | 17% | 12 h 30 min |
| September 18 | 79°F | 53°F | 29% | 17% | 12 h 20 min |
| September 19 | 79°F | 53°F | 29% | 17% | 12 h 20 min |
| September 20 | 79°F | 53°F | 29% | 17% | 12 h 20 min |
| September 21 | 78°F | 52°F | 29% | 17% | 12 h 20 min |
| September 22 | 78°F | 52°F | 29% | 17% | 12 h 10 min |
| September 23 | 78°F | 52°F | 28% | 17% | 12 h 10 min |
| September 24 | 77°F | 51°F | 28% | 17% | 12 h 10 min |
| September 25 | 77°F | 51°F | 28% | 17% | 12 h 10 min |
| September 26 | 77°F | 50°F | 28% | 17% | 12 h |
| September 27 | 76°F | 50°F | 28% | 17% | 12 h |
| September 28 | 76°F | 50°F | 28% | 17% | 12 h |
| September 29 | 75°F | 49°F | 28% | 17% | 11 h 50 min |
| September 30 | 75°F | 49°F | 28% | 17% | 11 h 50 min |
- Normal high
- 80°FSeptember average
- Normal low
- 54°FSeptember average
- Precipitation
- 3.18 inmonth total
- Days with precipitation
- 80.01 inch or more
- Days at 90°F or more
- 4
- Daylight
- 13 h 10 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 27
- Days at 80°F or more
- 18
- Sunshine
- 82%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00013993; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in St. Joseph in September?
On a given September day the chance of 0.01 inch or more is 30% on average, highest around September 1 (31%). In all, 3.18 in falls on 8 days of a normal September, 1 of them with an inch or more.
In a normal September in St. Joseph, 4 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00013993.
What are the records for September in St. Joseph?
The warmest September temperature on this station's record (since 1908) is 107°F, on September 3, 1947; the coldest is 30°F, on September 28, 1967. The wettest September brought 12.24 in (1986).
The September mean against the 1991-2020 normal of 67.0°F: 2021 70.0°F (+3.0), 2022 66.3°F (−0.7), 2023 70.3°F (+3.3), 2024 69.7°F (+2.7), 2025 69.3°F (+2.3), 2026 75.2°F (+8.2). 5 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 70.0°F | +3.0°F | 1.18 in |
| 2022 | 66.3°F | −0.7°F | 2.30 in |
| 2023 | 70.3°F | +3.3°F | 0.98 in |
| 2024 | 69.7°F | +2.7°F | 1.31 in |
| 2025 | 69.3°F | +2.3°F | 1.61 in |
| 2026 | 75.2°F | +8.2°F | 7.23 in |
Source: records: ACIS, station USW00013993; recent months: ACIS, station USW00013993. Records and recent months use complete months only.
How does September in St. Joseph compare across Missouri?
Across the 134 places PlainClimate covers in Missouri, September normal highs run from 76°F in Unionville to 85°F in Kennett; St. Joseph's is 80°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.