Mason City weather in May: Mason City, Iowa: normal highs, lows, rain and records for May
Mason City in May has a normal high of 70°F and a normal low of 47°F, a daily mean of 58°F, rising from 64°F on the 1st to 75°F by the 31st. Measurable precipitation falls on 14 days in a normal May, 5.15 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 21°C and low of 8°C, 131 mm of precipitation and 1 cm of snow in May.
- NOAA stationMason City Municipal Airport
- Station IDUSW00014940
- Location43.15°N 93.33°W
- Elevation1,225 ft (373 m)
- From the center6 miles
- Population26,948
- Jan 24° 7°
- Feb 29° 11°
- Mar 42° 24°
- Apr 58° 35°
- May 70° 47°
- Jun 80° 57°
- Jul 83° 61°
- Aug 80° 58°
- Sep 74° 49°
- Oct 60° 37°
- Nov 44° 24°
- Dec 30° 14°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Mason City in May?
The normal high is 70°F and the normal low 47°F, for a daily mean of 58.2°F. May is 12.2°F warmer than April and 10.3°F cooler than June. May is the 5th warmest month of the year in Mason City and the 2nd wettest. Across the month the normal high rises 11°F, from 64°F on May 1 to 75°F on May 31. From one year to the next May's mean temperature typically moves about 2.9°F either way (NOAA's standard deviation), so roughly two Mays in three average between 55°F and 61°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 44%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| May 1 | 64°F | 40°F | 42% | 27% |
| May 8 | 67°F | 43°F | 43% | 27% |
| May 15 | 69°F | 46°F | 43% | 27% |
| May 22 | 72°F | 49°F | 43% | 28% |
| May 31 | 75°F | 53°F | 43% | 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 | 64°F | 40°F | 42% | 27% | 14 h |
| May 2 | 64°F | 41°F | 42% | 27% | 14 h 10 min |
| May 3 | 65°F | 41°F | 43% | 27% | 14 h 10 min |
| May 4 | 65°F | 42°F | 43% | 27% | 14 h 10 min |
| May 5 | 66°F | 42°F | 43% | 27% | 14 h 10 min |
| May 6 | 66°F | 43°F | 43% | 27% | 14 h 20 min |
| May 7 | 66°F | 43°F | 43% | 27% | 14 h 20 min |
| May 8 | 67°F | 43°F | 43% | 27% | 14 h 20 min |
| May 9 | 67°F | 44°F | 43% | 27% | 14 h 20 min |
| May 10 | 67°F | 44°F | 43% | 27% | 14 h 30 min |
| May 11 | 68°F | 45°F | 43% | 27% | 14 h 30 min |
| May 12 | 68°F | 45°F | 43% | 27% | 14 h 30 min |
| May 13 | 69°F | 46°F | 43% | 27% | 14 h 30 min |
| May 14 | 69°F | 46°F | 43% | 27% | 14 h 40 min |
| May 15 | 69°F | 46°F | 43% | 27% | 14 h 40 min |
| May 16 | 70°F | 47°F | 43% | 27% | 14 h 40 min |
| May 17 | 70°F | 47°F | 43% | 27% | 14 h 40 min |
| May 18 | 70°F | 48°F | 43% | 27% | 14 h 40 min |
| May 19 | 71°F | 48°F | 43% | 27% | 14 h 50 min |
| May 20 | 71°F | 49°F | 43% | 28% | 14 h 50 min |
| May 21 | 72°F | 49°F | 43% | 28% | 14 h 50 min |
| May 22 | 72°F | 49°F | 43% | 28% | 14 h 50 min |
| May 23 | 72°F | 50°F | 43% | 28% | 14 h 50 min |
| May 24 | 73°F | 50°F | 43% | 28% | 15 h |
| May 25 | 73°F | 51°F | 44% | 28% | 15 h |
| May 26 | 73°F | 51°F | 43% | 28% | 15 h |
| May 27 | 74°F | 51°F | 43% | 28% | 15 h |
| May 28 | 74°F | 52°F | 43% | 28% | 15 h |
| May 29 | 74°F | 52°F | 43% | 28% | 15 h |
| May 30 | 75°F | 53°F | 43% | 28% | 15 h 10 min |
| May 31 | 75°F | 53°F | 43% | 28% | 15 h 10 min |
- Normal high
- 70°FMay average
- Normal low
- 47°FMay average
- Precipitation
- 5.15 inmonth total
- Days with precipitation
- 140.01 inch or more
- Snowfall
- 0.3 inmonth total
- Days at 90°F or more
- 1
- Nights at 32°F or colder
- 1
- Daylight
- 14 h to 15 h 10 minMay 1 to May 31
- Days at 70°F or more
- 17
- Days at 80°F or more
- 6
- Sunshine
- 70%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00014940; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Mason City in May?
On a given May day the chance of 0.01 inch or more is 43% on average, highest around May 25 (44%). In all, 5.15 in falls on 14 days of a normal May, 1 of them with an inch or more.
In a normal May in Mason City, 1 days reach 90°F, 1 nights fall to freezing and snowfall averages 0.3 inches.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00014940.
How humid and windy is Mason City in May?
At 3 p.m. the normal temperature is 73°F with 48% relative humidity and a dew point of 52°F; at 6 a.m. it is 57°F with 84% humidity. The wind averages 10.7 mph, most often from the south-southwest in the afternoon.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 57°F | 52°F | 84% | 8.5 mph | 57% |
| 9 a.m. | 66°F | 54°F | 65% | 12.0 mph | 54% |
| noon | 71°F | 53°F | 53% | 13.1 mph | 49% |
| 3 p.m. | 73°F | 52°F | 48% | 13.3 mph | 46% |
| 6 p.m. | 71°F | 52°F | 52% | 12.3 mph | 53% |
| 9 p.m. | 63°F | 53°F | 70% | 8.9 mph | 58% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00014940. 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 Mason City?
The warmest May temperature on this station's record (since 1948) is 99°F, on May 14, 2013; the coldest is 22°F, on May 3, 2005. The wettest May brought 12.90 in (2004); the snowiest, 9.5 inches (2013).
The May mean against the 1991-2020 normal of 58.2°F: 2021 57.9°F (−0.3), 2022 58.9°F (+0.7), 2023 61.5°F (+3.3), 2024 59.5°F (+1.3), 2025 59.0°F (+0.8), 2026 59.1°F (+0.9). 5 of 6 ran warmer than normal.
| May | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 57.9°F | −0.3°F | 2.84 in |
| 2022 | 58.9°F | +0.7°F | 2.57 in |
| 2023 | 61.5°F | +3.3°F | 3.55 in |
| 2024 | 59.5°F | +1.3°F | 8.19 in |
| 2025 | 59.0°F | +0.8°F | 1.95 in |
| 2026 | 59.1°F | +0.9°F | 2.70 in |
Source: records: ACIS, station USW00014940; recent months: ACIS, station USW00014940. Records and recent months use complete months only.
How does May in Mason City 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; Mason City's is 70°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.