Mahaska County, Iowa · Oskaloosa
Water spreading, a burst pipe, sewage, mold or smoke? Call to be connected with a restoration company that serves Oskaloosa, New Sharon and Eddyville. Start the steps below while you wait.
Answered 24/7 by a participating local provider. We're a referral service and don't do the work ourselves. How it works
Start here
Pick the closest match. These steps limit the damage and protect your insurance claim. Skip anything that isn't safe.
Mahaska County averages 54 nights a year at 20°F or colder, mostly November to March, and 47% of its homes predate 1960.
Heavy rain days of an inch or more come about 5.6 times a year here, most often in July. A sump pump that hasn't run since last season is a common weak point.
Backups often follow heavy rain, which Mahaska County gets about 5.6 days a year, when storm water overloads sewer mains and pushes up through the lowest drain in the house.
In Mahaska County, 2.67 inches fell on the wettest day of the 2015–2024 record. Storms like that, and ice dams in snowy winters, cause most roof leaks.
19% of occupied homes in Mahaska County heat mainly with wood or propane, below the Iowa county median of 22.1%.
With 38 muggy nights a year, mold in Mahaska County can appear within days of a leak. Dry first, then clean.
Local risk profile
About 22,021 people live in Mahaska County, 571 square miles in southern Iowa, in roughly 9,728 homes. The county seat is Oskaloosa, and New Sharon, Eddyville and Fremont round out the largest towns. Half the homes here were built before 1965, half after.
35/100 Water Damage Risk Index: Moderate Mahaska County ranks 88 of 99 Iowa counties. See the statewide ranking and method.The three factors where Mahaska County ranks highest compared with other Iowa counties.
Winters here are on the gentler end for Iowa, and pipes still freeze. From 2015–2024 it averaged 54 nights a year at 20°F or colder, the range where pipes in exterior walls, crawl spaces and unheated garages freeze, and 130 nights at or below 32°F. That ranks 71st of 99 counties.
On January 31, 2019 the low fell to about -25°F, and in the stretch ending January 2018 the county went 16 days in a row below freezing. Leaks from split pipes typically appear the day the thaw arrives.
The freeze season here runs November to March, with January the coldest. If you travel then, leave the thermostat at 55°F or above and open sink cabinets on outside walls.
Freezing nights typically start around Oct 19 and end around Apr 24.
Mahaska gets fewer downpours than most Iowa counties, but they still fill basements. About 5.6 days a year bring an inch or more (96th of 99), most often in July, out of 34.1 inches of total precipitation. On November 5, 2022, 2.67 inches fell in a single day. The worst three-day stretch dropped 3.51 inches, ending July 31, 2024, the kind of soaking that overwhelms sump pumps and storm sewers.
About 92 days a year swing from below freezing at night to above freezing by day. Those freeze-thaw cycles feed ice dams on roofs, open cracks in foundations and driveways, and stress pipes that are already marginal.
Housing
67% of homes in Mahaska County predate 1980, close to the Iowa county median of 72.8%, which ranks 65th of Iowa's 99 counties.
Housing age is mixed: 47% of homes are pre-1960 and 14% are 2000 or newer. Ask any plumber which era your house is from and you'll know which failures to watch for.
Renters occupy 32% of homes. If you rent, the building is usually the landlord's to repair, but your belongings are only covered by renters insurance.
Beyond water
Mahaska County averages 38 warm, muggy nights a year (lows of 65°F or more) and gets the most rain in May. Keep indoor humidity under 60%, as the EPA advises, and dry any leak within 24 to 48 hours; in a humid month a wet basement left alone won't dry by itself.
Mold remediation: what to expectMain heating fuel in Mahaska County's occupied homes: 53% utility gas, 27% electric, 17% propane and 3% wood. Wood heat is more common here than the state median. Have chimneys swept and fuel-burning appliances serviced each fall, and keep three feet clear around stoves and space heaters.
Fire and smoke cleanup: first stepsCoverage
Calls connect to restoration companies that work across Mahaska County. The largest communities by population:
Population from ACS 2020-2024 5-year estimates. Townships and unincorporated areas are covered too.
Nearby
Jasper, Keokuk and Poweshiek get more pipe-freeze nights than Mahaska. Keokuk County has the oldest housing nearby, with 80% of homes built before 1980.
By the numbers
| Factor | Mahaska | Iowa median | Rank |
|---|---|---|---|
| Homes built before 1960 | 47% | 48% | 52 of 99 |
| Homes built before 1980 | 67% | 73% | 65 of 99 |
| Homes built 2000 or later | 14% | 13% | 46 of 99 |
| Manufactured or mobile homes | 4.9% | 3.2% | 22 of 99 |
| Vacant homes | 10% | 9.5% | 38 of 99 |
| Wood or propane heat | 19% | 22% | 68 of 99 |
| Nights at 20°F or colder | 54/yr | 62/yr | 71 of 99 |
| Days with 1 inch+ of rain | 5.6/yr | 7.1/yr | 96 of 99 |
| Freeze-thaw days | 92/yr | 94/yr | 67 of 99 |
| Muggy nights (65°F+) | 38/yr | 29/yr | 19 of 99 |
Rank 1 is the highest value. Bars run from the lowest to the highest Iowa county; the tick marks the median; orange means higher water damage risk than the median, green means lower.
Questions
Peak risk months in Mahaska County: freezing from November to March, heavy rain in July, September and October.
Sources: U.S. Census Bureau, ACS 2024 5-year estimates (2020-2024); weather from NOAA nClimGrid-Daily county averages (EpiNOAA), 2015–2024, averaged across the county; county boundaries from Census TIGER. Reviewed 2026-10-21. Methodology