Ottumwa weather in May: Ottumwa, Iowa: normal highs, lows, rain and records for May
Ottumwa in May has a normal high of 73°F and a normal low of 51°F, a daily mean of 62°F, rising from 68°F on the 1st to 78°F by the 31st. Measurable precipitation falls on 13 days in a normal May, 5.03 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 23°C and low of 11°C, 128 mm of precipitation in May.
- NOAA stationOttumwa Industrial Airport
- Station IDUSW00014950
- Location41.11°N 92.45°W
- Elevation842 ft (257 m)
- From the center6 miles
- Population25,648
- Jan 32° 14°
- Feb 37° 18°
- Mar 50° 29°
- Apr 63° 39°
- May 73° 51°
- Jun 82° 61°
- Jul 86° 65°
- Aug 84° 62°
- Sep 77° 53°
- Oct 64° 42°
- Nov 50° 30°
- Dec 37° 20°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Ottumwa in May?
The normal high is 73°F and the normal low 51°F, for a daily mean of 62.0°F. May is 10.9°F warmer than April and 9.6°F cooler than June. May is the 5th warmest month of the year in Ottumwa and the 2nd wettest. Across the month the normal high rises 10°F, from 68°F on May 1 to 78°F on May 31. From one year to the next May's mean temperature typically moves about 3.0°F either way (NOAA's standard deviation), so roughly two Mays in three average between 59°F and 65°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 42%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| May 1 | 68°F | 45°F | 42% | 27% |
| May 8 | 70°F | 48°F | 42% | 28% |
| May 15 | 73°F | 51°F | 42% | 29% |
| May 22 | 75°F | 53°F | 42% | 28% |
| May 31 | 78°F | 57°F | 41% | 28% |
Every day of May: normal high, low and chance of precipitation (warmest afternoon May 31, coldest night May 1)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| May 1 | 68°F | 45°F | 42% | 27% | 14 h |
| May 2 | 68°F | 46°F | 42% | 28% | 14 h |
| May 3 | 69°F | 46°F | 42% | 28% | 14 h |
| May 4 | 69°F | 46°F | 42% | 28% | 14 h |
| May 5 | 69°F | 47°F | 42% | 28% | 14 h 10 min |
| May 6 | 70°F | 47°F | 42% | 28% | 14 h 10 min |
| May 7 | 70°F | 48°F | 42% | 28% | 14 h 10 min |
| May 8 | 70°F | 48°F | 42% | 28% | 14 h 10 min |
| May 9 | 71°F | 48°F | 42% | 28% | 14 h 10 min |
| May 10 | 71°F | 49°F | 42% | 28% | 14 h 20 min |
| May 11 | 71°F | 49°F | 42% | 28% | 14 h 20 min |
| May 12 | 72°F | 50°F | 42% | 28% | 14 h 20 min |
| May 13 | 72°F | 50°F | 42% | 29% | 14 h 20 min |
| May 14 | 72°F | 50°F | 42% | 29% | 14 h 30 min |
| May 15 | 73°F | 51°F | 42% | 29% | 14 h 30 min |
| May 16 | 73°F | 51°F | 42% | 29% | 14 h 30 min |
| May 17 | 73°F | 51°F | 42% | 28% | 14 h 30 min |
| May 18 | 74°F | 52°F | 42% | 28% | 14 h 30 min |
| May 19 | 74°F | 52°F | 42% | 28% | 14 h 30 min |
| May 20 | 74°F | 53°F | 42% | 28% | 14 h 40 min |
| May 21 | 75°F | 53°F | 42% | 28% | 14 h 40 min |
| May 22 | 75°F | 53°F | 42% | 28% | 14 h 40 min |
| May 23 | 75°F | 54°F | 42% | 28% | 14 h 40 min |
| May 24 | 76°F | 54°F | 42% | 29% | 14 h 40 min |
| May 25 | 76°F | 55°F | 42% | 29% | 14 h 40 min |
| May 26 | 76°F | 55°F | 42% | 28% | 14 h 50 min |
| May 27 | 77°F | 55°F | 41% | 28% | 14 h 50 min |
| May 28 | 77°F | 56°F | 41% | 28% | 14 h 50 min |
| May 29 | 77°F | 56°F | 41% | 28% | 14 h 50 min |
| May 30 | 78°F | 56°F | 41% | 28% | 14 h 50 min |
| May 31 | 78°F | 57°F | 41% | 28% | 14 h 50 min |
- Normal high
- 73°FMay average
- Normal low
- 51°FMay average
- Precipitation
- 5.03 inmonth total
- Days with precipitation
- 130.01 inch or more
- Days at 90°F or more
- 1
- Daylight
- 14 h to 14 h 50 minMay 1 to May 31
- Days at 70°F or more
- 19
- Days at 80°F or more
- 8
- Sunshine
- 72%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00014950; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Ottumwa in May?
On a given May day the chance of 0.01 inch or more is 42% on average, highest around May 9 (42%). In all, 5.03 in falls on 13 days of a normal May, 1 of them with an inch or more.
In a normal May in Ottumwa, 1 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00014950.
How humid and windy is Ottumwa in May?
At 3 p.m. the normal temperature is 75°F with 53% relative humidity and a dew point of 57°F; at 6 a.m. it is 60°F with 84% humidity. The wind averages 9.9 mph, most often from the south-southwest in the afternoon.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 60°F | 55°F | 84% | 8.5 mph | 61% |
| 9 a.m. | 67°F | 57°F | 69% | 10.9 mph | 60% |
| noon | 73°F | 57°F | 57% | 12.1 mph | 53% |
| 3 p.m. | 75°F | 57°F | 53% | 12.0 mph | 50% |
| 6 p.m. | 73°F | 57°F | 56% | 10.6 mph | 59% |
| 9 p.m. | 66°F | 57°F | 72% | 8.2 mph | 65% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00014950. 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 May in Ottumwa?
The warmest May temperature on this station's record (since 1948) is 97°F, on May 28, 2018; the coldest is 24°F, on May 3, 2005. The wettest May brought 10.72 in (1996).
The May mean against the 1991-2020 normal of 62.0°F: 2021 59.6°F (−2.4), 2022 63.7°F (+1.7), 2023 63.8°F (+1.8), 2024 63.5°F (+1.5), 2025 61.3°F (−0.7), 2026 62.5°F (+0.5). 4 of 6 ran warmer than normal.
| May | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 59.6°F | −2.4°F | 5.00 in |
| 2022 | 63.7°F | +1.7°F | 1.96 in |
| 2023 | 63.8°F | +1.8°F | 0.93 in |
| 2024 | 63.5°F | +1.5°F | 5.20 in |
| 2025 | 61.3°F | −0.7°F | 0.83 in |
| 2026 | 62.5°F | +0.5°F | 2.06 in |
Source: records: ACIS, station USW00014950; recent months: ACIS, station USW00014950. Records and recent months use complete months only.
How does May in Ottumwa compare across Iowa?
Across the 132 places PlainClimate covers in Iowa, May normal highs run from 66°F in Northwood to 74°F in Glenwood; Ottumwa's is 73°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.