Warren County, Illinois · Monmouth
Water spreading, a burst pipe, sewage, mold or smoke? Call to be connected with a restoration company that serves Monmouth, Roseville and Alexis. 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.
Pipes freeze in Warren County on about 46 nights a year, mostly November to March. Older homes, 56% of the stock here, are most at risk.
Basements flood here mostly in July. Warren County averages 6.8 days a year with an inch of rain or more.
Sewage backups in Warren County spike on heavy-rain days, about 6.8 a year, when sewer mains fill up and water finds the lowest drain.
Warren County's wettest day in the 2015–2024 record brought 2.66 inches, and about 89 freeze-thaw days a year mean ice dams in some winters.
23% of occupied homes in Warren County heat mainly with wood or propane, above the Illinois county median of 16.5%.
About 40 nights a year here stay at 65°F or warmer, so basements and crawl spaces can grow mold even without a leak.
Local risk profile
With 7,587 homes and around 16,447 residents, Warren County is 542 square miles of northwest Illinois. Besides Monmouth, the county seat, the biggest communities are Roseville, Alexis and Kirkwood. It has some of the oldest housing in the state: the median home went up in 1956.
62/100 Water Damage Risk Index: Elevated Warren County ranks 15 of 102 Illinois counties. See the statewide ranking and method.The three factors where Warren County ranks highest compared with other Illinois counties.
Warren is on the colder side of Illinois for pipes. In the 2015–2024 record the county logged about 46 nights a year at or below 20°F (17th of 102) and 124 below freezing. Twenty degrees is roughly where uninsulated pipes start to freeze.
The longest cold spell was straight 15 days without the temperature rising above freezing, ending in January 2018. The coldest night reached about -23°F on January 31, 2019. Burst pipes usually show up when a spell like that breaks and the ice thaws.
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.
On average the first fall freeze arrives around Oct 22 and the last spring freeze around Apr 24.
Warren gets fewer downpours than most Illinois counties, but they still fill basements. About 6.8 days a year bring an inch or more (88th of 102), most often in July, out of 36.7 inches of total precipitation. On June 22, 2016, 2.66 inches fell in a single day. Multi-day storms matter most for basements; the wettest three days on record here totaled 4.01 inches (through September 8, 2018).
The temperature crosses 32°F in both directions on roughly 89 days a year. Each cycle melts and refreezes water at roof edges and in foundation cracks, which is how ice dams and basement seepage get started.
Housing
84% of homes in Warren County predate 1980, above the Illinois county median of 65.9%, which ranks 1st of Illinois's 102 counties.
In Warren County 56% of homes are older than 1960. If yours is one of them and the plumbing has never been replaced, expect galvanized steel supply pipe and cast iron drain lines, the two materials most likely to fail quietly.
Beyond water
About 40 nights a year in Warren County stay at 65°F or warmer, a sign of muggy summer air (73rd of 102 counties). May is the wettest month. 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 expectHeating fuel matters for fire risk. In Warren County it's 57% utility gas, 18% electric, 20% propane and 2% wood. Propane heat is above the Illinois norm. Annual chimney and vent inspection, which the NFPA recommends, is one of the most effective fire-prevention habits for these homes.
Fire and smoke cleanup: first stepsCoverage
Calls connect to restoration companies that work across Warren County. The largest communities by population:
Population from ACS 2020-2024 5-year estimates. Townships and unincorporated areas are covered too.
Nearby
Mercer gets more pipe-freeze nights than Warren. All of its neighbors see more heavy-rain days. Its housing is the oldest in the area by share of homes built before 1980.
By the numbers
| Factor | Warren | Illinois median | Rank |
|---|---|---|---|
| Homes built before 1960 | 56% | 38% | 2 of 102 |
| Homes built before 1980 | 84% | 66% | 1 of 102 |
| Homes built 2000 or later | 7.2% | 15% | 98 of 102 |
| Manufactured or mobile homes | 2.6% | 5.6% | 78 of 102 |
| Vacant homes | 11% | 11% | 53 of 102 |
| Wood or propane heat | 23% | 17% | 25 of 102 |
| Nights at 20°F or colder | 46/yr | 35/yr | 17 of 102 |
| Days with 1 inch+ of rain | 6.8/yr | 8.4/yr | 88 of 102 |
| Freeze-thaw days | 89/yr | 81/yr | 11 of 102 |
| Muggy nights (65°F+) | 40/yr | 51/yr | 73 of 102 |
Rank 1 is the highest value. Bars run from the lowest to the highest Illinois county; the tick marks the median; orange means higher water damage risk than the median, green means lower.
Questions
Peak risk months in Warren County: freezing from November to March, heavy rain in June, July and August.
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