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Denison weather in numbers
from 30 years of measured normals
Denison swings 67°F across the year, from 82°F highs in July to 15°F lows in January, and June is usually the wettest month in a year that brings about 33 in of precipitation.
Warmest month
July
82°F average high
Coldest month
January
15°F average low
Wettest month
June
33 in a year
Below freezing
5 months
January, February, March, November and December
Comfortable
3 months
May, September and October
Residents
8,334
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The weather map: all three models at once
NWS, American, European side by side around Denison and nearby towns.Live rain radar →
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Denison 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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Denison 10-day forecast, out to 14 days
where the models agree, and where they split
Denison, Iowa (IA) is at its warmest in Jul (average highs near 82°F) and coldest in Jan (lows around 15°F), with roughly 33 in of precipitation across the year. Below, compare what NWS, American, European forecast for Denison right now, and see exactly where they disagree.
average daytime high and overnight low across a typical year (1991-2020)
Jan
28°
15°
Feb
37°
16°
Mar
47°
27°
Apr
59°
38°
May
71°
50°
Jun
80°
60°
Jul
82°
65°
Aug
80°
63°
Sep
73°
54°
Oct
60°
42°
Nov
46°
29°
Dec
34°
20°
Source: 1991-2020 averages, ERA5 for this place adjusted with NASA POWER.
How Denison's weather has changed since 1995
30 years of daily data, 1995-2024, shown as change
+1.1°F
Around Denison, the difference between 1995-2004 and 2015-2024 is +1.1°F, within the normal swing from year to year.
1995each stripe is one year2024
cooler than averagearound averagewarmer than average
Days above 95°F
no clear change
2015-2024 against 1995-2004. Within the normal year-to-year swing
Frost nights
5 fewer nights a year
2015-2024 against 1995-2004, below 32°F. Within the normal year-to-year swing
Average wind
−2%
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 >95°F vs avg
Frost nights vs avg
Wind vs avg
1995
−1.2°F
+4
+6
+1%
1996
−4.1°F
−9
+22
+1%
1997
−1.0°F
+1
+17
−1%
1998
+1.1°F
−9
−18
−7%
1999
+0.8°F
−5
−12
+3%
2000
+0.6°F
+1
−4
+1%
2001
+0.2°F
+2
−7
−1%
2002
+0.2°F
+9
+21
+3%
2003
−0.3°F
+6
−3
−1%
2004
−0.1°F
−9
−5
+1%
2005
+2.0°F
+12
+1
+1%
2006
+2.2°F
+11
−1
+3%
2007
±0.0°F
−5
−3
+3%
2008
−2.8°F
−9
+15
+3%
2009
−2.5°F
−9
−2
−3%
2010
−1.6°F
−9
−5
−5%
2011
−0.3°F
−3
+9
−1%
2012
+4.4°F
+28
−23
+1%
2013
−1.6°F
+1
+22
+3%
2014
−2.8°F
−9
+8
+1%
2015
±0.0°F
−8
−18
−3%
2016
+1.3°F
−9
−19
−1%
2017
+1.1°F
+0
−9
−1%
2018
−1.8°F
−8
+21
−5%
2019
−2.5°F
−9
+16
−3%
2020
+0.8°F
+3
+9
−1%
2021
+2.0°F
+1
−14
−3%
2022
+0.4°F
+12
+11
+7%
2023
+2.4°F
+6
−2
−7%
2024
+3.1°F
−1
−23
−1%
Source: NASA POWER daily data from the MERRA-2 reanalysis, 1995-2024. Each value describes a grid square of about 50 km around Denison, 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 the US?
CheckWeather Score, graded against the weather that actually happened
Provider
CheckWeather-score
Temp
Wind
Rain
Run by
European ★ Best
93
/100rank #1
91±0.9°F
97±1.1 mph
9396% hit
ECMWF - European Centre for Medium-Range Weather ForecastsReading, United Kingdom
American
82
/100rank #2
83±1.7°F
94±2.0 mph
7184% hit
NOAA / NCEP (United States)College Park, Maryland, USA
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Common questions
What's the weather in Denison today?
On this page we show what NWS, American, European each forecast for Denison 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 Denison today or tomorrow?
Check the hourly strip and 7-day forecast above. We compare rain from NWS, American, European for Denison 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 Denison?
No single model is always right. NWS, American, European each run their own physics, so we line all three up: when they agree the Denison forecast is reliable, and when they split you should expect surprises. See our tested US accuracy scoreboard for how the models compare.
What is the warmest month in Denison?
July is typically the warmest month in Denison, with average highs around 82°F.
How cold does Denison get?
The coldest month in Denison is January, when overnight lows average about 15°F.
How much rain does Denison get?
Denison sees roughly 33 in of precipitation a year, with June usually the wettest month.
Is Denison getting warmer?
Not clearly. In NASA's reanalysis for the area around Denison, the difference between 1995-2004 and 2015-2024 is 1.1°F, within the normal swing from year to year.
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