This ranking identifies U.S. ZIP codes with the highest and lowest mold risk. Mold growth depends on moisture, which is influenced by climate, housing conditions, and water infrastructure reliability. Mold exposure causes respiratory illness, allergic reactions, and property damage.
41,344 ZIP codes analyzed · Worst score: 92/100
25 Worst ZIP Codes
| # | ZIP Code | City | State | Mold Score | Level | Avg Humidity |
|---|---|---|---|---|---|---|
| 1 | 70112 | New Orleans | LA | 92/100 | very_high | 80% |
| 2 | 70113 | New Orleans | LA | 92/100 | very_high | 80% |
| 3 | 70115 | New Orleans | LA | 92/100 | very_high | 80% |
| 4 | 70116 | New Orleans | LA | 92/100 | very_high | 80% |
| 5 | 70117 | New Orleans | LA | 92/100 | very_high | 80% |
| 6 | 70118 | New Orleans | LA | 92/100 | very_high | 80% |
| 7 | 70119 | New Orleans | LA | 92/100 | very_high | 80% |
| 8 | 70125 | New Orleans | LA | 92/100 | very_high | 80% |
| 9 | 70130 | New Orleans | LA | 92/100 | very_high | 80% |
| 10 | 70121 | New Orleans | LA | 89/100 | very_high | 80% |
| 11 | 70122 | New Orleans | LA | 89/100 | very_high | 80% |
| 12 | 71301 | Alexandria | LA | 87/100 | very_high | 79% |
| 13 | 33155 | Miami | FL | 86/100 | very_high | 78% |
| 14 | 70114 | New Orleans | LA | 86/100 | very_high | 80% |
| 15 | 33020 | Hollywood | FL | 85/100 | very_high | 78% |
| 16 | 33023 | Hollywood | FL | 85/100 | very_high | 78% |
| 17 | 33139 | Miami Beach | FL | 85/100 | very_high | 78% |
| 18 | 33140 | Miami Beach | FL | 85/100 | very_high | 78% |
| 19 | 33141 | Miami Beach | FL | 85/100 | very_high | 78% |
| 20 | 33161 | Miami | FL | 85/100 | very_high | 78% |
| 21 | 71104 | Shreveport | LA | 85/100 | very_high | 79% |
| 22 | 33013 | Hialeah | FL | 84/100 | very_high | 78% |
| 23 | 33144 | Miami | FL | 84/100 | very_high | 78% |
| 24 | 33150 | Miami | FL | 84/100 | very_high | 78% |
| 25 | 33167 | Miami | FL | 84/100 | very_high | 78% |
25 Best ZIP Codes
| # | ZIP Code | City | State | Mold Score | Level | Avg Humidity |
|---|---|---|---|---|---|---|
| 1 | 89163 | The Lakes | NV | 0/100 | very_low | 36% |
| 2 | 89087 | North Las Vegas | NV | 0/100 | very_low | 36% |
| 3 | 89067 | Coyote Springs | NV | 0/100 | very_low | 36% |
| 4 | 89037 | Coyote Springs | NV | 0/100 | very_low | 36% |
| 5 | 89036 | North Las Vegas | NV | 0/100 | very_low | 36% |
| 6 | 89033 | North Las Vegas | NV | 0/100 | very_low | 36% |
| 7 | 89028 | Laughlin | NV | 0/100 | very_low | 36% |
| 8 | 89026 | Jean | NV | 0/100 | very_low | 36% |
| 9 | 89023 | Mercury | NV | 0/100 | very_low | 36% |
| 10 | 88905 | The Lakes | NV | 0/100 | very_low | 36% |
| 11 | 88901 | The Lakes | NV | 0/100 | very_low | 36% |
| 12 | 88433 | Quay | NM | 0/100 | very_low | 38% |
| 13 | 88213 | Caprock | NM | 0/100 | very_low | 38% |
| 14 | 88133 | Saint Vrain | NM | 0/100 | very_low | 38% |
| 15 | 88123 | Lingo | NM | 0/100 | very_low | 38% |
| 16 | 88122 | Kenna | NM | 0/100 | very_low | 38% |
| 17 | 88036 | Fort Bayard | NM | 0/100 | very_low | 38% |
| 18 | 87933 | Derry | NM | 0/100 | very_low | 38% |
| 19 | 87654 | Spaceport City | NM | 0/100 | very_low | 38% |
| 20 | 87117 | Kirtland Afb | NM | 0/100 | very_low | 38% |
| 21 | 87060 | Tome | NM | 0/100 | very_low | 38% |
| 22 | 87009 | Cedarvale | NM | 0/100 | very_low | 38% |
| 23 | 86435 | Supai | AZ | 0/100 | very_low | 34% |
| 24 | 86412 | Hualapai | AZ | 0/100 | very_low | 34% |
| 25 | 85309 | Glendale Luke Afb | AZ | 0/100 | very_low | 34% |
Rankings by State
| State | ZIP Codes |
|---|---|
| Texas | 2,649 |
| California | 2,630 |
| New York | 2,186 |
| Pennsylvania | 2,184 |
| Illinois | 1,583 |
| Florida | 1,484 |
| Ohio | 1,435 |
| Virginia | 1,228 |
| Michigan | 1,167 |
| Missouri | 1,161 |
| North Carolina | 1,085 |
| Iowa | 1,058 |
| Minnesota | 1,009 |
| Indiana | 980 |
| Georgia | 964 |
| Kentucky | 947 |
| Wisconsin | 898 |
| West Virginia | 855 |
| Alabama | 819 |
| Tennessee | 787 |
| Oklahoma | 771 |
| Kansas | 749 |
| Washington | 726 |
| New Jersey | 726 |
| Louisiana | 723 |
Methodology
Mold risk scores combine four factors: average relative humidity (annual and seasonal), housing vintage (pre-1980 construction), FEMA flood insurance claim history, and water system infrastructure violations. Higher scores indicate greater mold risk. Data sources: NOAA humidity data, FEMA NFIP, American Community Survey, EPA SDWIS.
Last updated: 2026-06-04.
Frequently Asked Questions
How are these rankings calculated?
Rankings are based on federal agency data including EPA, FEMA, USGS, and PHMSA. Each ZIP code receives a score based on the specific risk factors for this category. See the methodology section above for details.
How often are rankings updated?
Rankings are regenerated quarterly using the latest available data. The date shown reflects the most recent update.
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