Dallas County Climate
Dallas County, Iowa
Avg Annual Temp
48.9°F
Annual Precip
36.1"
Annual Snowfall
—
Extreme Heat Days
20.2
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Seasonal Overview
National Comparison
Climate Profile
About Dallas County Weather
A Classic Midwestern Continental Climate
Dallas County maintains an average annual temperature of 48.9°F, which sits below the national median for U.S. counties. This humid continental climate experiences distinct seasonal shifts and reliable precipitation, averaging 36.1 inches annually. Residents navigate a landscape that is notably cooler than the more temperate regions of the American South.
Warmer Than the Iowa Average
With an annual average of 48.9°F, Dallas County is nearly a full degree warmer than the statewide average of 48.0°F. While much of Iowa faces harsher northern winds, this central county enjoys a slightly more moderate thermal profile. It aligns perfectly with the state's average precipitation of 36.1 inches, supporting the region's productive agricultural roots.
Balanced Weather in Central Iowa
Dallas County's 48.9°F average temperature makes it warmer than northern neighbors like Dickinson, which sits at 45.9°F. It provides a middle ground between the colder northern tier and the warmer southern counties like Davis. This positioning results in a climate that avoids the extreme cold of the border while maintaining manageable summer peaks.
Sharp Seasonal Swings and Summer Heat
Summers in Dallas County are intense, with an average of 20 days per year reaching or exceeding 90°F. Winter brings a significant chill as the January average drops to 19.8°F and the seasonal average hovers at 23.2°F. While specific local snowfall data is unavailable, the county's winter profile suggests consistent frozen precipitation throughout the season.
Prepare for High-Efficiency Living
The 20 days of extreme heat require robust HVAC systems to handle the 74.5°F July average. Since winter temperatures frequently drop below 20°F in January, high-quality home insulation and heavy-duty winter gear are essential for local comfort. Residents should plan for a wide range of outdoor conditions given the county's nearly 55-degree spread between winter and summer lows.
Frequently Asked Questions
What is the average temperature in Dallas County?
How much rain does Dallas County get?
How hot does Dallas County get in summer?
How cold are winters in Dallas County?
Track your own weather in Dallas County
Ambient Weather personal weather stations give you hyperlocal climate data.
Sponsored
Data source: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020.
Climate normals are 30-year averages of weather variables computed from 1991 to 2020. Station data is aggregated to county level using spatial averaging. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.