Climate change in Ottumwa, Iowa

Climate change is affecting locations like Ottumwa in a variety of ways. In fall, these impacts include more extreme rainfall, more unusually warm days, and greater health risks from humid heat.

Explore these pages to learn how people in Ottumwa are at risk in a warming world.

Since 1970, average annual temperatures in Ottumwa have gotten 0.9°F warmer.

Warming puts people and ecosystems at risk from more frequent and intense extreme weather.
Overall, the contiguous U.S. is about 2.8°F warmer today than in 1970, based on average temperatures.
Data source: NOAA ACIS

Since 1970, Ottumwa's annual precipitation has decreased by 1.9 inches.

Climate change is supercharging the water cycle and bringing heavier precipitation extremes across the U.S.
For every 1°F of warming, the air can hold 4% more moisture, increasing the chances of heavier downpours that contribute to flash flooding hazards.
Data source: NOAA ACIS

As of October 9, 2026, Ottumwa has experienced 27 days this year with temperatures made twice as likely by climate change.

This is according to the Climate Shift Index (CSI), which quantifies the influence of human-caused climate change on daily average temperatures. Temperatures on these days had a CSI level 2 or higher, which indicates local temperatures were at least two times more likely due to climate change.
The CSI ranges from -5 to +5. Positive levels indicate temperatures made more likely due to climate change (while negative scores indicate conditions made less likely).
Data source: Climate Shift Index

Ottumwa's climate threats in include:

During the past 20 years, Iowa experienced 40 more billion-dollar disasters from severe storms compared to the previous 20 years.

As the planet warms, extreme weather events are becoming more frequent and intense, resulting in devastating losses.
This data shows how the total number of severe storms with at least one billion dollars in damages has changed from 1980-1999 to 2005-2024.
Data source: NCEI U.S. Billion-Dollar Weather and Climate Disasters

The amount of rainfall during the heaviest rain events each year in the Midwest has increased by 45% since 1958.

Climate change is supercharging the water cycle, bringing heavier precipitation extremes across the U.S.
This chart shows how the amount of rainfall during the top 1% heaviest rain events each year in the Midwest increased between 1958 to 2021.
Data source: Fifth National Climate Assessment

Since 1979, Ottumwa has experienced 9 fewer days with a heat index above 90°F.

Heat is dangerous. When high temperatures are combined with high humidity, the health risks multiply.
The heat index incorporates relative humidity and is more useful than air temperature alone in determining heat-related health risks.
Data source: gridMET

Explore some ways climate change is affecting Ottumwa in fall

Heavier downpours

Climate change is supercharging the water cycle, driving heavier rainfall and flood risk.

Key concepts:

Climate change is supercharging the water cycle, driving heavier rainfall and flood risk.
From 1958–2021, extreme precipitation days grew in every region, led by the Northeast (+60%) and Midwest (+45%).
Intensification will continue with future warming.
Short bursts of extreme rain threaten people, ecosystems, and infrastructure nationwide.

Learn more

More warm fall days

Fall (September-November) has warmed nationwide since 1970.

Key concepts:

Fall (September - November) has warmed nationwide since 1970.
Warming is nationwide, strongest in the Southwest.
Hotter falls extend risks from heat, wildfire, allergies, and more.

Learn more

More dangerous heat

Climate change is driving hotter, longer, and more frequent extreme heat.

Key concepts:

Climate change is driving hotter, longer, and more frequent extreme heat — the deadliest U.S. weather hazard.
Heat combined with humidity multiplies health risks.
Rising humidity slows sweat evaporation, straining the body’s cooling system and causing dangerous heat stress.

Learn more

Changes in severe storms

Certain conditions favorable to thunderstorms and tornadoes are occurring more often

Key concepts:

Severe storms make up half of U.S. billion-dollar disasters since 1980.
Climate change is shifting storm conditions into new seasons and regions.

Learn more

Impacts to food prices

Extreme events fueled by climate change can damage crops, reduce yields, and disrupt supply chains.

Key concepts:

Food and climate change are closely linked. Food systems account for about one-quarter of all heat-trapping pollution.
Meanwhile, extreme events fueled by climate change can damage crops, reduce yields, and disrupt supply chains — all of which can drive food prices higher.
The availability, quality, and affordability of food reflect a complex set of climatic and socioeconomic factors. Emerging research is providing insight into the role of climate change.

Learn more

More graphics about Ottumwa and climate change

Browse climate-related graphics for all seasons localized for Ottumwa, available for download and use consistent with our Terms of use.

Filter by keywords

Show per page:

Discover more nearby

See all supported locations

Climate change in Ottumwa, Iowa

Ottumwa's climate threats in fall include:

Explore some ways climate change is affecting Ottumwa in fall

Discover more nearby

Other Climate Central Resources

Ottumwa's climate threats in include: