iDry Columbus
Mold Risk by ZIP Code
Mold Risk by ZIP Code
Enter your ZIP to see your area's environmental mold-risk level and the climate factors driving it. Free, instant, no signup.
Check your area
High-risk area — or already seeing mold?
iDry Columbus does mold inspection, testing, and remediation across Central Ohio.
Call / Text 614-810-0000This index estimates ENVIRONMENTAL mold risk from regional climate normals — humidity, dew point, and rainfall (NOAA-based). It is not an air-quality test and does not measure mold in a specific building. Local factors — elevation, proximity to water, home age, ventilation, and prior water damage — move your actual risk up or down. For Columbus, OH, see our neighborhood-level index.
Mold risk by ZIP — frequently asked questions
How is mold risk by ZIP code calculated?
This index uses regional climate normals — average humidity, dew point, and annual rainfall (NOAA-based) for your area — to estimate how favorable the outdoor climate is for mold. Warmer, wetter, more humid regions keep building materials damp longer, which raises environmental mold risk. It does not measure mold inside a specific home.
Which states have the highest mold risk?
The Gulf Coast and humid Southeast — Florida, Louisiana, Mississippi, Alabama, and Hawaii — have the highest environmental mold risk from year-round heat and humidity. Arid states like Arizona, Nevada, and Utah have the lowest. Most of the Midwest and Mid-Atlantic, including Ohio, fall in the moderate range.
What humidity level prevents mold?
Keep indoor relative humidity below 50% (ideally 30–50%). Above about 60% RH, mold can begin to grow on damp surfaces. A dehumidifier sized to your space, good ventilation, and fixing leaks within 24–48 hours are the most effective controls.
Does a high-risk ZIP mean my home has mold?
No. This is a climate-based environmental index, not a test of your specific building. A high-risk area means conditions favor mold, so prevention matters more — but a well-ventilated, leak-free home in a high-risk ZIP can be mold-free, while a damp basement in a low-risk ZIP can have mold. Local factors decide.
How can I check mold risk for my exact neighborhood?
For Columbus, Ohio, we publish a neighborhood-level mold risk index scoring 26 areas using FEMA flood zones, housing age, waterway proximity, and soil drainage — far more granular than ZIP-level climate. For your home specifically, a moisture inspection is the only definitive check.