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Mason City weather in numbers
measured normals and 10 years of recorded weather
Mason City swings 69°F across the year, from 80°F highs in July to 11°F lows in February, and June is usually the wettest month in a year that brings about 36 in of precipitation. Over 10 years of recorded weather it averages 89 days a year at 77°F or above, 18 of them at 86°F or above, 137 frost nights, and rain on 109 days.
Warmest month
July
80°F average high
Coldest month
February
11°F average low
Wettest month
June
36 in a year
Comfortable
3 months
May, August and September
Residents
27,000
share this forecast
Most accurate here
European
96/100 CheckWeather Score
Warm days
89 days
a year at 77°F or above
Frost nights
137 nights
a year below 32°F
Rain days
109 days
a year with 0.04 in or more
Day counts are from the ERA5 reanalysis for Mason City’s grid square, 2016 to 2025, counted the same way for every city so the numbers compare. A reanalysis square is an area, not a weather station, so it is good for counting days and not for a single day’s record.
The weather map: all three models at once
NWS, American, European side by side around Mason City and nearby towns.Live rain radar →
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Mason City hourly forecast: next 14 hours
consensus of the three models
Rain in the next 24 hours, model by model
each model's own hourly precipitation, side by side
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Mason City 10-day forecast, out to 14 days
where the models agree, and where they split
Mason City, Iowa (IA) is at its warmest in Jul (average highs near 80°F) and coldest in Feb (lows around 11°F), with roughly 36 in of precipitation across the year. Below, compare what NWS, American, European forecast for Mason City right now, and see exactly where they disagree.
average daytime high and overnight low across a typical year (1991-2020)
Jan
24°
12°
Feb
32°
11°
Mar
44°
24°
Apr
57°
37°
May
70°
49°
Jun
79°
60°
Jul
80°
63°
Aug
78°
61°
Sep
71°
53°
Oct
58°
41°
Nov
43°
28°
Dec
30°
17°
Source: 1991-2020 averages, ERA5 for this place adjusted with NASA POWER.
How Mason City's weather has changed since 1995
30 years of daily data, 1995-2024, shown as change
+1.0°F
Around Mason City, the difference between 1995-2004 and 2015-2024 is +1.0°F, within the normal swing from year to year.
1995each stripe is one year2024
cooler than averagearound averagewarmer than average
Days above 86°F
no clear change
2015-2024 against 1995-2004. Within the normal year-to-year swing
Frost nights
2 fewer nights a year
2015-2024 against 1995-2004, below 32°F. Within the normal year-to-year swing
Average wind
−1%
2015-2024 against 1995-2004. Within the normal year-to-year swing
Bars: each year against the area's 30-year average. Dashed lines: the average of the first and the last ten years.
See the numbers year by year
Year
Temp vs average
Days >86°F vs avg
Frost nights vs avg
Wind vs avg
1995
−1.3°F
−1
+7
+0%
1996
−3.5°F
−10
+21
+4%
1997
−1.3°F
−0
+17
+0%
1998
+2.3°F
−5
−23
−6%
1999
+0.5°F
−2
−7
+2%
2000
−0.3°F
+2
−7
+0%
2001
−0.1°F
−1
−5
−2%
2002
+0.6°F
+22
+18
+2%
2003
−0.1°F
+9
−8
+0%
2004
−0.1°F
−15
−0
+0%
2005
+1.4°F
+13
−0
−2%
2006
+2.1°F
+14
+1
+2%
2007
+0.1°F
−6
−4
+4%
2008
−2.8°F
−16
+14
+0%
2009
−2.1°F
−13
−0
−2%
2010
−0.8°F
−7
−14
−4%
2011
−0.1°F
+3
−0
−2%
2012
+4.6°F
+46
−17
+0%
2013
−2.2°F
−6
+21
+0%
2014
−3.3°F
−17
+3
+4%
2015
+0.8°F
−4
−16
+0%
2016
+1.2°F
−11
−18
−2%
2017
+0.6°F
−9
−10
+0%
2018
−1.5°F
−5
+23
−6%
2019
−2.2°F
−13
+15
−2%
2020
−0.1°F
−5
+12
−2%
2021
+2.4°F
+24
−11
−4%
2022
−1.0°F
+3
+12
+6%
2023
+3.3°F
+33
−2
−4%
2024
+3.2°F
−9
−20
+0%
Source: NASA POWER daily data from the MERRA-2 reanalysis, 1995-2024. Each value describes a grid square of about 50 km around Mason City, not a weather station, and a square that takes in sea or a large lake runs milder than the city itself. That is why this section shows change against the square's own 30-year average rather than counts you could compare with a local station. Rain and snow are left out because their long-term record in this dataset is not consistent over time. "Within the normal year-to-year swing" means the change is smaller than the usual differences between single years.
Which forecast is most accurate in Mason City?
CheckWeather Score, graded against the weather that actually happened
Provider
CheckWeather-score
Temp
Wind
Rain
Run by
European ★ Best
96
/100rank #1
96±0.4°F
98±0.6 mph
9597% hit
ECMWF - European Centre for Medium-Range Weather ForecastsReading, United Kingdom
American
80
/100rank #2
83±1.7°F
95±1.6 mph
6581% hit
NOAA / NCEP (United States)College Park, Maryland, USA
The accuracy above is the measured record. This is your opinion: which forecast service do you trust most in United States? Give each 1 to 5 stars.
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Common questions
What's the weather in Mason City today?
On this page we show what NWS, American, European each forecast for Mason City today, side by side and updated live. When all three agree the forecast is reliable; when they split, we flag it so you know the day is genuinely less certain.
Will it rain in Mason City today or tomorrow?
Check the hourly strip and 7-day forecast above. We compare rain from NWS, American, European for Mason City and flag the days where the models disagree on whether showers actually arrive, which is exactly when a single app can catch you out.
Which forecast is most accurate for Mason City?
Over the last 30 days, the European model has been the most accurate for Mason City (CheckWeather Score 96/100), ahead of the American at 80. We grade every model against the recorded weather. See the US accuracy scoreboard for the full method.
What is the warmest month in Mason City?
July is typically the warmest month in Mason City, with average highs around 80°F.
How cold does Mason City get?
The coldest month in Mason City is February, when overnight lows average about 11°F.
How much rain does Mason City get?
Mason City sees roughly 36 in of precipitation a year, with June usually the wettest month.
Is Mason City getting warmer?
Not clearly. In NASA's reanalysis for the area around Mason City, the difference between 1995-2004 and 2015-2024 is 1.0°F, within the normal swing from year to year.