Annual mean
Annual mean of daily highs
Annual mean of daily lows
Portland CDP, Iowa
Official LSAD Designation: Portland CDP • Census GEOID: 1964155
• Cerro Gordo County
Climate Normals & Weather Observations
30-year climate normals (1991–2020) and weather observations for Portland CDP.
Reference Weather Station: MASON CITY, IA US (ID: USC00135230)
• Located 4.1 miles from community center
• Elevation: 336.8 m
| Month | Average High (°F) | Average Low (°F) | Mean Temp (°F) | Precipitation (in) |
|---|---|---|---|---|
| January | 24.0° | 7.0° | 15.5° | 0.89" |
| February | 28.6° | 10.9° | 19.8° | 1.07" |
| March | 41.3° | 23.0° | 32.1° | 1.95" |
| April | 56.4° | 34.7° | 45.6° | 3.91" |
| May | 68.6° | 46.9° | 57.8° | 5.58" |
| June | 78.7° | 57.6° | 68.2° | 5.70" |
| July | 81.9° | 61.5° | 71.7° | 4.63" |
| August | 79.6° | 58.8° | 69.2° | 3.71" |
| September | 73.5° | 50.1° | 61.8° | 3.24" |
| October | 60.1° | 37.6° | 48.8° | 2.55" |
| November | 43.3° | 25.2° | 34.2° | 1.79" |
| December | 29.9° | 14.2° | 22.0° | 1.25" |
Annual Temperature History
2010–2025, completed calendar years only.
NOAA station MASON CITY, IA US (ID: USC00135230) • 4.1 miles from community center .
This is the same reference station used for monthly normals.
Source: NOAA NCEI Global Summary of the Year.
Annual temperature data table (°F)
| Year | Annual mean (°F) | Annual mean of daily highs (°F) | Annual mean of daily lows (°F) |
|---|---|---|---|
| 2010 | 45.6 | 55.9 | 35.2 |
| 2011 | 45.6 | 55.7 | 35.4 |
| 2012 | 49.6 | 60.8 | 38.5 |
| 2013 | 43.6 | 53.4 | 33.7 |
| 2014 | 42.2 | 52.2 | 32.2 |
| 2015 | Unavailable | 56.9 | Unavailable |
| 2016 | Unavailable | 58.0 | Unavailable |
| 2017 | 47.4 | 57.4 | 37.5 |
| 2018 | 44.9 | 54.2 | 35.6 |
| 2019 | 44.3 | 53.9 | 34.8 |
| 2020 | 46.9 | 57.3 | 36.6 |
| 2021 | 48.2 | 58.6 | 37.7 |
| 2022 | 44.8 | 55.5 | 34.1 |
| 2023 | 48.3 | 59.1 | 37.4 |
| 2024 | 49.4 | 60.3 | 38.4 |
| 2025 | 47.3 | 58.3 | 36.3 |
Source: NOAA NCEI 1991–2020 U.S. Climate Normals, National Weather Service.