Ottumwa weather in May

In May, Ottumwa sees average daytime highs of 72°F and overnight lows near 53°F, with 4.8 in of precipitation across 12.7 wet days and about 14.3 hours of daylight. It is the 5th-warmest and 2nd-wettest month of the year here.

Highs climb over the month, from about 67°F in the first days to 76°F by the end. The sky is clear or mostly clear about 26% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 42 min at the start of May to 14 h 42 min by month's end. Set against the rest of the year, May is Ottumwa's 7th-clearest and 8th-windiest month. For the whole year in context, see Ottumwa's year-round climate.

Daytime high
72°
5th warmest
Overnight low
53°
8th coldest
Precipitation
4.8 in
12.7 wet days
Daylight
14 h 18 min
4:57 AM – 7:14 PM
Cloud cover
62%
7th clearest
Wind
9 mph
8th windiest
Solar energy
5.72 kWh/m²
Travel score
6.2
out of 10

Ottumwa is city in and the county seat of Wapello County, Iowa, United States.

Density
575/km²
people per km²
Founded
1844

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 67°F in the first days to 76°F by the end.

A typical May day in Ottumwa reaches about 72°F in the afternoon and slips back to 53°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 59°F and 83°F. Set against its neighbours, May runs about 10°F warmer than April and about 9°F cooler than June.

40°60°80°151015202531
Avg high (°F)Avg low (°F)
16747
26748
36748
46849
56849
66950
76950
86951
97051
107051
117051
127152
137152
147153
157253
167253
177253
187354
197354
207355
217355
227455
237456
247456
257556
267557
277657
287658
297658
307758
317759

How May really feels in Ottumwa

Once humidity and wind are folded in, May 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

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

Ottumwa weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan32° / 16°1.46.84.59.40.0
Feb36° / 20°1.874.310.40.0
Mar49° / 31°2.792.511.72.1
Apr62° / 42°4.311.60.813.14.9
May72° / 53°4.812.70.114.36.2
Jun81° / 63°5.011.8014.96.0
Jul85° / 67°3.39.6014.65.4
Aug83° / 64°3.59.4013.66.2
Sep76° / 56°3.68.1012.37.2
Oct64° / 44°2.87.90.210.95.9
Nov49° / 32°2.26.71.29.72.2
Dec37° / 22°1.86.33.59.10.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 26% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 16% of May, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13862
23862
33862
43961
53961
63961
73961
84060
94159
104159
114258
124258
134258
144357
154357
164357
174357
184357
194357
204357
214357
224456
234456
244456
254555
264456
274456
284456
294555
304654
314555

Chance of precipitation in May

Any precipitation

Ottumwa gets around 4.8 in of rain and snow over 12.7 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 41% and peaks near 42% on the wettest days, and about 0 day brings snow.

0%10%20%30%40%50%151015202531
Rain chance (%)
142
242
342
442
542
642
742
842
942
1042
1141
1241
1340
1440
1540
1640
1739
1839
1940
2040
2140
2240
2340
2440
2541
2641
2742
2842
2942
3042
3142

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the dry band about 64% of days. Sticky, muggy-or-worse air turns up on roughly 6% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1859510
28310610
38111710
47912810
57712920
675131020
774131120
872141220
971141320
1070141330
1169141430
1268141530
1368141530
1467141540
1566141640
1665141650
1765141650
1863151750
1962151760
2060151870
2160151870
2257161980
2356161981
2454171991
25511820101
26511820101
27491920111
28481920121
29462020131
30442021141
31432021151

Wind in May

Winds average 9 mph in May.

Across May, daily wind ranges from about 8 mph on the calmest days to 10 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
110light breeze
210light breeze
39light breeze
49light breeze
59light breeze
69light breeze
79light breeze
89light breeze
99light breeze
109light breeze
119light 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
308light breeze
318light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 42 min at the start of May to 14 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 60 minutes over May. Sunrise moves from 5:15 AM to 4:46 AM, and sunset from 6:59 PM to 7:28 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.75:156:59
213.85:147:00
313.85:127:01
413.95:117:02
513.95:107:03
613.95:087:04
714.05:077:05
814.05:067:06
914.05:057:07
1014.15:047:08
1114.15:037:09
1214.25:017:10
1314.25:007:11
1414.24:597:12
1514.34:587:13
1614.34:577:14
1714.34:567:15
1814.44:557:16
1914.44:547:17
2014.44:547:18
2114.44:537:19
2214.54:527:20
2314.54:517:21
2414.54:507:22
2514.64:507:23
2614.64:497:24
2714.64:487:25
2814.64:487:26
2914.74:477:26
3014.74:477:27
3114.74:467:28

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.72 kWh/m².

For context, solar energy here swings from a low near 1.82 kWh/m² to a high of 6.44 kWh/m² in July across the year — May's 5.72 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.3Bright
45.4Bright
55.4Bright
65.5Bright
75.5Bright
85.5Bright
95.6Bright
105.6Bright
115.6Bright
125.7Bright
135.7Bright
145.7Bright
155.8Bright
165.8Bright
175.8Bright
185.8Bright
195.8Bright
205.8Bright
215.9Bright
225.9Bright
235.9Bright
245.9Bright
255.9Bright
265.9Bright
275.9Bright
285.9Bright
296.0Bright
306.0Bright
316.0Intense
Planning a trip in May

Is May a good time to visit Ottumwa?

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

6.2
Sightseeing
2nd-best month of the year
4.4
Beach & pool
5th-best month of the year

May is a reasonable time to visit Ottumwa for sightseeing.

What to pack for Ottumwa in May

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

In May, Ottumwa sees daytime highs around 72°F and nights near 53°F. Worth packing: light clothes, rain gear and sun protection. About 13 days see rain.

light clothesrain gearsun protection

UV index in Ottumwa in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Ottumwa peaks around June 20 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 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 highHighModerateLowJun 20UV 9Dec 19UV 2
UV index (midday)Level
Jan2Moderate
Feb3Moderate
Mar4Moderate
Apr6High
May7Very high
Jun10Very high
Jul9Very high
Aug8Very high
Sep6High
Oct4Moderate
Nov3Moderate
Dec2Low

Air quality in Ottumwa in May

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Ottumwa is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (October, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateGoodJul 1816 µg/m³Oct 217 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb14Moderate
Mar13Moderate
Apr11Good
May12Moderate
Jun13Moderate
Jul17Moderate
Aug14Moderate
Sep12Good
Oct7Good
Nov8Good
Dec10Good
Location & terrain

Where is Ottumwa?

Ottumwa sits at 41.0°N, 92.4°W, 673 ft above sea level, in United States. The nearest listed city is Newton, 57 mi away.

Topography around Ottumwa

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

Within 2 miles, the terrain around Ottumwa has only modest variations in elevation — a maximum elevation change of 249 ft around an average of 715 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 574 ft.

The land around Ottumwa is covered by trees (45%), artificial surfaces (25%) and grassland (20%) within 2 miles, cropland (40%), trees (33%) and grassland (24%) within 10 miles, and cropland (52%), grassland (25%) and trees (22%) within 50 miles.

2 miles
249 ft
10 miles
322 ft
50 miles
574 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Newton 57 mi · Kirksville 58 mi · Coralville 63 mi · Iowa City 63 mi · Indianola 64 mi · North Liberty 66 mi · Burlington 70 mi · Altoona 70 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 Ottumwa (41.02°, -92.4113°, elevation 673 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).