Indianola weather in September

In September, Indianola sees average daytime highs of 76°F and overnight lows near 55°F, with 3.6 in of rain across 8.3 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 80°F in the first days to 71°F by the end. The sky is clear or mostly clear about 49% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Indianola's 1st-clearest and 9th-windiest month. For the whole year in context, see Indianola's year-round climate.

Daytime high
76°
4th warmest
Overnight low
55°
9th coldest
Rainfall
3.6 in
8.3 wet days
Daylight
12 h 18 min
6:00 AM – 6:17 PM
Cloud cover
44%
1st clearest
Wind
9 mph
9th windiest
Solar energy
4.69 kWh/m²
Travel score
7.2
out of 10

Indianola is city in Warren County, Iowa, United States.

Density
531/km²
people per km²
Founded
1849

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 71°F by the end.

A typical September day in Indianola reaches about 76°F in the afternoon and slips back to 55°F overnight — a 20°F spread between the day's warmth and the night's chill. On most days the high lands between 64°F and 86°F. Set against its neighbours, September runs about 7°F cooler than August and about 13°F warmer than October.

40°60°80°151015202530
Avg high (°F)Avg low (°F)
18161
28161
38061
48060
58060
67959
77959
87858
97858
107858
117757
127757
137756
147656
157656
167555
177555
187555
197454
207454
217453
227353
237352
247352
257252
267251
277151
287150
297150
307050

How September really feels in Indianola

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.

Indianola weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan31° / 15°1.26.14.49.40.0
Feb35° / 19°1.66.64.610.30.0
Mar49° / 30°2.792.511.72.0
Apr61° / 41°4.311.2113.14.9
May71° / 53°5.313.20.114.36.1
Jun81° / 63°4.911.6014.96.1
Jul84° / 67°3.89.8014.75.6
Aug83° / 64°3.59.4013.76.4
Sep76° / 55°3.68.3012.37.2
Oct63° / 43°2.87.80.310.95.8
Nov48° / 31°2.16.81.49.72.0
Dec36° / 20°1.663.79.10.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 49% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 37%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16535
26535
36634
46634
56535
66634
76535
86436
96436
106337
116238
126238
136139
146139
156139
166139
176139
186139
196139
206238
216238
226337
236337
246238
256337
266337
276337
286436
296436
306436

Chance of precipitation in September

Any precipitation

Indianola gets around 3.6 in of rain over 8.3 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 30% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
127
227
327
427
527
627
727
828
928
1028
1129
1229
1330
1430
1530
1630
1730
1830
1930
2030
2129
2229
2328
2428
2527
2627
2727
2826
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 49% of days. Sticky, muggy-or-worse air turns up on roughly 16% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1212322268
2232322257
3252422237
4272422226
5292422205
6312421195
7342321184
8362321174
9382320163
10402220153
11422219152
12442218142
13452118142
14472117142
15492017131
16502016131
17531915121
18541914121
19561814111
20571813111
21601712101
2262171191
2364171081
2466161080
256816970
267015960
277115860
287215850
297414750
307514740

Wind in September

Winds average 9 mph in September.

Across September, daily wind ranges from about 8 mph on the calmest days to 9 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
129light breeze
139light breeze
149light breeze
159light breeze
169light breeze
179light breeze
189light breeze
199light breeze
209light breeze
219light breeze
229light breeze
239light breeze
249light breeze
259light breeze
269light breeze
279light breeze
289light breeze
299light breeze
309light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 hours 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 84 minutes over September. Sunrise moves from 5:45 AM to 6:15 AM, and sunset from 6:43 PM to 5:52 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:456:43
212.95:466:41
312.95:476:40
412.85:486:38
512.85:496:36
612.75:506:34
712.75:516:33
812.65:526:31
912.65:536:29
1012.65:546:27
1112.55:556:26
1212.55:566:24
1312.45:576:22
1412.45:586:20
1512.35:596:19
1612.36:006:17
1712.26:016:15
1812.26:026:13
1912.16:046:11
2012.16:056:10
2112.06:066:08
2212.06:076:06
2311.96:086:04
2411.96:096:02
2511.86:106:01
2611.86:115:59
2711.86:125:57
2811.76:135:55
2911.76:145:54
3011.66:155:52

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.69 kWh/m².

For context, solar energy here swings from a low near 1.84 kWh/m² to a high of 6.47 kWh/m² in July across the year — September's 4.69 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.3Bright
25.2Bright
35.2Bright
45.2Bright
55.1Bright
65.1Bright
75.0Bright
85.0Bright
95.0Bright
104.9Bright
114.9Bright
124.8Bright
134.8Bright
144.7Bright
154.7Bright
164.6Bright
174.6Bright
184.5Bright
194.5Bright
204.4Bright
214.4Bright
224.3Bright
234.3Bright
244.3Bright
254.2Bright
264.2Bright
274.2Bright
284.1Bright
294.1Bright
304.0Bright
Planning a trip in September

Is September a good time to visit Indianola?

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

7.2
Sightseeing
1st-best month of the year
6.1
Beach & pool
4th-best month of the year

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

What to pack for Indianola in September

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

In September, Indianola sees daytime highs around 76°F and nights near 55°F. Worth packing: light clothes, rain gear and sun protection. About 8 days see rain.

light clothesrain gearsun protection

UV index in Indianola 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 Indianola peaks around June 20 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 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 highHighModerateJun 20UV 9Dec 21UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May7High
Jun10Very high
Jul9Very high
Aug8Very high
Sep6High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Indianola 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 Indianola is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (October, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateGoodJul 1915 µg/m³Oct 217 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb14Moderate
Mar13Moderate
Apr10Good
May11Good
Jun12Moderate
Jul16Moderate
Aug14Moderate
Sep12Good
Oct7Good
Nov8Good
Dec10Good
Location & terrain

Where is Indianola?

Indianola sits at 41.4°N, 93.6°W, 968 ft above sea level, in United States. The nearest listed city is Des Moines, 17 mi away.

Topography around Indianola

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

Within 2 miles, the terrain around Indianola has only modest variations in elevation — a maximum elevation change of 190 ft around an average of 912 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 305 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 741 ft.

The land around Indianola is covered by grassland (34%), trees (25%) and cropland (24%) within 2 miles, cropland (43%), grassland (30%) and trees (25%) within 10 miles, and cropland (53%) and grassland (26%) within 50 miles.

2 miles
190 ft
10 miles
305 ft
50 miles
741 ft
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Des Moines 17 mi · West Des Moines 17 mi · Clive 19 mi · Urbandale 21 mi · Altoona 21 mi · Johnston 23 mi · Waukee 24 mi · Ankeny 26 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 Indianola (41.358°, -93.5574°, elevation 968 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).