Lafayette weather in September: Lafayette, Indiana: normal highs, lows, rain and records for September
Lafayette in September has a normal high of 77°F and a normal low of 54°F, a daily mean of 66°F, falling from 81°F on the 1st to 72°F by the 30th. Measurable precipitation falls on 9 days in a normal September, 2.59 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 25°C and low of 12°C, 66 mm of precipitation in September.
- NOAA stationLafayette Purdue University Airport
- Station IDUSW00014835
- Location40.41°N 86.94°W
- Elevation599 ft (183 m)
- Population71,757
- Jan 33° 18°
- Feb 38° 21°
- Mar 50° 30°
- Apr 62° 40°
- May 73° 51°
- Jun 81° 60°
- Jul 84° 63°
- Aug 83° 62°
- Sep 77° 54°
- Oct 65° 43°
- Nov 50° 33°
- Dec 38° 24°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Lafayette in September?
The normal high is 77°F and the normal low 54°F, for a daily mean of 65.5°F. September is 6.7°F cooler than August and 11.8°F warmer than October. September is the 4th warmest month of the year in Lafayette and the 9th wettest. Across the month the normal high falls 9°F, from 81°F on September 1 to 72°F on September 30. From one year to the next September's mean temperature typically moves about 2.8°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 63°F and 68°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 32%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 81°F | 59°F | 32% | 17% |
| September 8 | 80°F | 57°F | 32% | 17% |
| September 15 | 78°F | 54°F | 31% | 16% |
| September 22 | 75°F | 52°F | 30% | 16% |
| September 30 | 72°F | 49°F | 30% | 16% |
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 | 81°F | 59°F | 32% | 17% | 13 h 10 min |
| September 2 | 81°F | 59°F | 32% | 17% | 13 h 10 min |
| September 3 | 81°F | 58°F | 32% | 17% | 13 h |
| September 4 | 81°F | 58°F | 32% | 17% | 13 h |
| September 5 | 80°F | 58°F | 32% | 17% | 13 h |
| September 6 | 80°F | 57°F | 32% | 17% | 13 h |
| September 7 | 80°F | 57°F | 32% | 17% | 12 h 50 min |
| September 8 | 80°F | 57°F | 32% | 17% | 12 h 50 min |
| September 9 | 80°F | 56°F | 32% | 16% | 12 h 50 min |
| September 10 | 79°F | 56°F | 31% | 16% | 12 h 40 min |
| September 11 | 79°F | 56°F | 31% | 16% | 12 h 40 min |
| September 12 | 79°F | 55°F | 31% | 16% | 12 h 40 min |
| September 13 | 78°F | 55°F | 31% | 16% | 12 h 40 min |
| September 14 | 78°F | 55°F | 31% | 16% | 12 h 30 min |
| September 15 | 78°F | 54°F | 31% | 16% | 12 h 30 min |
| September 16 | 77°F | 54°F | 30% | 16% | 12 h 30 min |
| September 17 | 77°F | 53°F | 30% | 16% | 12 h 30 min |
| September 18 | 77°F | 53°F | 30% | 16% | 12 h 20 min |
| September 19 | 76°F | 53°F | 30% | 16% | 12 h 20 min |
| September 20 | 76°F | 52°F | 30% | 16% | 12 h 20 min |
| September 21 | 76°F | 52°F | 30% | 16% | 12 h 20 min |
| September 22 | 75°F | 52°F | 30% | 16% | 12 h 10 min |
| September 23 | 75°F | 51°F | 30% | 16% | 12 h 10 min |
| September 24 | 74°F | 51°F | 30% | 16% | 12 h 10 min |
| September 25 | 74°F | 50°F | 30% | 16% | 12 h 10 min |
| September 26 | 74°F | 50°F | 30% | 16% | 12 h |
| September 27 | 73°F | 50°F | 30% | 16% | 12 h |
| September 28 | 73°F | 49°F | 30% | 16% | 12 h |
| September 29 | 72°F | 49°F | 30% | 16% | 11 h 50 min |
| September 30 | 72°F | 49°F | 30% | 16% | 11 h 50 min |
- Normal high
- 77°FSeptember average
- Normal low
- 54°FSeptember average
- Precipitation
- 2.59 inmonth total
- Days with precipitation
- 90.01 inch or more
- Days at 90°F or more
- 3
- Daylight
- 13 h 10 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 25
- Days at 80°F or more
- 14
- Sunshine
- 80%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00014835; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Lafayette in September?
On a given September day the chance of 0.01 inch or more is 31% on average, highest around September 1 (32%). In all, 2.59 in falls on 9 days of a normal September, 1 of them with an inch or more.
In a normal September in Lafayette, 3 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00014835.
How humid and windy is Lafayette in September?
At 3 p.m. the normal temperature is 71°F with 47% relative humidity and a dew point of 49°F; at 6 a.m. it is 52°F with 88% humidity. The wind averages 6.7 mph, most often from the west in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 52°F | 49°F | 88% | 4.7 mph | 67% |
| 9 a.m. | 58°F | 51°F | 78% | 6.7 mph | 67% |
| noon | 68°F | 51°F | 55% | 9.4 mph | 63% |
| 3 p.m. | 71°F | 49°F | 47% | 9.9 mph | 63% |
| 6 p.m. | 68°F | 49°F | 52% | 7.6 mph | 67% |
| 9 p.m. | 59°F | 50°F | 73% | 5.6 mph | 74% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00014835. 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 September in Lafayette?
The warmest September temperature on this station's record (since 1944) is 98°F, on September 2, 2011; the coldest is 29°F, on September 23, 1995. The wettest September brought 8.81 in (1965).
The September mean against the 1991-2020 normal of 65.5°F: 2021 69.6°F (+4.1), 2022 66.0°F (+0.5), 2023 67.5°F (+2.0), 2024 69.1°F (+3.6), 2025 68.0°F (+2.5), 2026 71.6°F (+6.1). 6 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 69.6°F | +4.1°F | 2.75 in |
| 2022 | 66.0°F | +0.5°F | 1.11 in |
| 2023 | 67.5°F | +2.0°F | 0.59 in |
| 2024 | 69.1°F | +3.6°F | 1.64 in |
| 2025 | 68.0°F | +2.5°F | 3.12 in |
| 2026 | 71.6°F | +6.1°F | 2.13 in |
Source: records: ACIS, station USW00014835; recent months: ACIS, station USW00014835. Records and recent months use complete months only.
How does September in Lafayette compare across Indiana?
Across the 99 places PlainClimate covers in Indiana, September normal highs run from 74°F in Angola to 82°F in English; Lafayette's is 77°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.