Lafayette weather in September

In September, Lafayette sees average daytime highs of 77°F and overnight lows near 56°F, with 2.7 in of rain across 8.1 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 80°F in the first days to 72°F by the end. The sky is clear or mostly clear about 42% of the time in September, and the air most often feels dry.

Daylight stretches from about 12 h 54 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Lafayette's 1st-clearest and 9th-windiest month. For the whole year in context, see Lafayette's year-round climate.

Daytime high
77°
4th warmest
Overnight low
56°
9th coldest
Rainfall
2.7 in
8.1 wet days
Daylight
12 h 18 min
6:34 AM – 6:50 PM
Cloud cover
49%
1st clearest
Wind
8 mph
9th windiest
Solar energy
4.57 kWh/m²
Travel score
7.1
out of 10

Lafayette is city in and the county seat of Tippecanoe County, Indiana, United States.

Density
932/km²
people per km²
Founded
1853

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 80°F in the first days to 72°F by the end.

A typical September day in Lafayette reaches about 77°F in the afternoon and slips back to 56°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 66°F and 87°F. Set against its neighbours, September runs about 5°F cooler than August and about 12°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18162
28162
38061
48061
58061
68060
78060
87960
97959
107959
117858
127858
137858
147757
157757
167756
177656
187656
197655
207555
217554
227554
237454
247453
257353
267353
277352
287252
297251
307251

How September really feels in Lafayette

Once humidity and wind are folded in, September averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Lafayette weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan34° / 20°2.79.14.99.40.0
Feb39° / 23°2.38.14.210.40.1
Mar50° / 32°3.310.42.411.72.2
Apr62° / 43°4.311.70.4135.0
May72° / 54°4.313.3014.26.1
Jun80° / 63°4.312.8014.86.0
Jul83° / 66°3.611.2014.65.7
Aug82° / 64°3.29.8013.66.5
Sep77° / 56°2.78.1012.37.1
Oct64° / 45°3.190.110.95.9
Nov50° / 35°3.18.51.29.82.4
Dec39° / 26°2.59.23.79.20.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 42% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 42%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15842
25842
35941
46040
56040
66040
76040
86040
96040
106040
116040
125941
135941
145842
155842
165842
175743
185743
195644
205644
215743
225644
235644
245644
255644
265545
275545
285545
295545
305644

Chance of precipitation in September

Any precipitation

Lafayette gets around 2.7 in of rain over 8.1 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 28% and peaks near 29% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
129
229
329
428
528
628
728
828
927
1027
1127
1227
1327
1427
1528
1628
1728
1828
1928
2028
2128
2228
2328
2428
2528
2627
2727
2827
2926
3026

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the dry band about 47% of days. Sticky, muggy-or-worse air turns up on roughly 15% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1212421259
2232421248
3242421237
4262521227
5282521216
6302520195
7322520184
8342520174
9352520163
10372520153
11392420142
12412420142
13422320132
14442320121
15462219121
16482119111
17502118101
1853201890
1954201790
2057191680
2159181580
2260181480
2363171370
2465161270
2565161270
2668151160
2768151160
2870141060
2972131050
3072131050

Wind in September

Winds average 8 mph in September.

Across September, daily wind ranges from about 7 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 54 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over September. Sunrise moves from 6:19 AM to 6:48 AM, and sunset from 7:15 PM to 6:25 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.96:197:15
212.96:207:14
312.96:217:12
412.86:227:10
512.86:237:09
612.76:247:07
712.76:257:05
812.66:267:04
912.66:277:02
1012.56:287:00
1112.56:296:58
1212.46:306:57
1312.46:316:55
1412.46:326:53
1512.36:336:51
1612.36:346:50
1712.26:356:48
1812.26:366:46
1912.16:376:44
2012.16:386:43
2112.06:396:41
2212.06:406:39
2311.96:416:38
2411.96:426:36
2511.96:436:34
2611.86:446:32
2711.86:456:31
2811.76:466:29
2911.76:476:27
3011.66:486:25

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.57 kWh/m².

For context, solar energy here swings from a low near 1.7 kWh/m² to a high of 6.32 kWh/m² in June across the year — September's 4.57 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.1Bright
25.1Bright
35.0Bright
45.0Bright
55.0Bright
64.9Bright
74.9Bright
84.8Bright
94.8Bright
104.8Bright
114.7Bright
124.7Bright
134.7Bright
144.6Bright
154.6Bright
164.5Bright
174.5Bright
184.5Bright
194.4Bright
204.4Bright
214.3Bright
224.3Bright
234.3Bright
244.2Bright
254.2Bright
264.1Bright
274.1Bright
284.0Bright
294.0Bright
304.0Moderate
Planning a trip in September

Is September a good time to visit Lafayette?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

7.1
Sightseeing
1st-best month of the year
6.2
Beach & pool
3rd-best month of the year

September is one of the better times to visit Lafayette for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Lafayette in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Lafayette sees daytime highs around 77°F and nights near 56°F. Worth packing: light clothes, rain gear and sun protection. About 8 days see rain.

light clothesrain gearsun protection

UV index in Lafayette in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Lafayette peaks around July 10 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 10UV 9Dec 23UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov3Moderate
Dec2Low

Air quality in Lafayette in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Lafayette is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (October, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateModerateGoodJul 1516 µg/m³Oct 218 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb13Moderate
Mar13Moderate
Apr12Good
May13Moderate
Jun15Moderate
Jul16Moderate
Aug14Moderate
Sep11Good
Oct7Good
Nov8Good
Dec9Good
Location & terrain

Where is Lafayette?

Lafayette sits at 40.4°N, 86.9°W, 692 ft above sea level, in United States. The nearest listed city is West Lafayette, 1.9 mi away.

Topography around Lafayette

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Lafayette.

Within 2 miles, the terrain around Lafayette has only modest variations in elevation — a maximum elevation change of 246 ft around an average of 630 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 322 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 627 ft.

The land around Lafayette is covered by artificial surfaces (49%) and trees (34%) within 2 miles, cropland (49%) and trees (28%) within 10 miles, and cropland (77%) within 50 miles.

2 miles
246 ft
10 miles
322 ft
50 miles
627 ft
treesgrasslandcroplandartificial surfaceswater
September weather nearby: West Lafayette 1.9 mi · Frankfort 21 mi · Crawfordsville 26 mi · Lebanon 34 mi · Logansport 36 mi · Kokomo 39 mi · Danville 45 mi · Zionsville 45 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Lafayette (40.4167°, -86.8753°, elevation 692 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).