2026 Rankings

EPA Radon Zone 1 ZIP Codes in Illinois - 2026

Last updated: August 31, 2026

797 ZIP codes ranked by Radon Zone #1: ZIP 61523 (Chillicothe, IL) - Zone 1 (highest potential)
Lead Violations Lowest Score Safest Flood Risk Energy Cost Radon PFAS Reliability EJ Index Homebuyer Risk CO & Gas Safest Gas Remediation Burden Unresolved Violations (by Utility) Water Equity (by Utility)

Out of 797 ZIP codes with data in Illinois, these are the lowest-ranked areas for radon zone. See also: National ZIP Codes in EPA Radon Zone 1 | All Illinois Rankings

Statistic Value
ZIP codes ranked 797
Lowest value Zone 1 (highest potential)
Median value Zone 1 (highest potential)
State Illinois

100 Lowest-Ranked ZIP Codes

Rank ZIP Code City State Radon Zone Safety Score
1 61523 Chillicothe IL Zone 1 (highest potential) 39/100
2 60177 South Elgin IL Zone 1 (highest potential) 40/100
3 61604 Peoria IL Zone 1 (highest potential) 44/100
4 61536 Hanna City IL Zone 1 (highest potential) 45/100
5 61547 Mapleton IL Zone 1 (highest potential) 45/100
6 61607 Peoria IL Zone 1 (highest potential) 45/100
7 61073 Roscoe IL Zone 1 (highest potential) 47/100
8 61615 Peoria IL Zone 1 (highest potential) 47/100
9 61072 Rockton IL Zone 1 (highest potential) 48/100
10 61111 Loves Park IL Zone 1 (highest potential) 48/100
11 61103 Rockford IL Zone 1 (highest potential) 49/100
12 61115 Machesney Park IL Zone 1 (highest potential) 49/100
13 61244 East Moline IL Zone 1 (highest potential) 50/100
14 61265 Moline IL Zone 1 (highest potential) 50/100
15 61282 Silvis IL Zone 1 (highest potential) 50/100
16 61525 Dunlap IL Zone 1 (highest potential) 50/100
17 61526 Edelstein IL Zone 1 (highest potential) 50/100
18 61528 Edwards IL Zone 1 (highest potential) 50/100
19 61552 Mossville IL Zone 1 (highest potential) 50/100
20 61602 Peoria IL Zone 1 (highest potential) 50/100
21 61603 Peoria IL Zone 1 (highest potential) 50/100
22 61606 Peoria IL Zone 1 (highest potential) 50/100
23 61614 Peoria IL Zone 1 (highest potential) 50/100
24 61616 Peoria Heights IL Zone 1 (highest potential) 50/100
25 61625 Peoria IL Zone 1 (highest potential) 50/100
26 61704 Bloomington IL Zone 1 (highest potential) 50/100
27 61705 Bloomington IL Zone 1 (highest potential) 50/100
28 62712 Springfield IL Zone 1 (highest potential) 50/100
29 61264 Milan IL Zone 1 (highest potential) 52/100
30 60124 Elgin IL Zone 1 (highest potential) 53/100
31 62563 Rochester IL Zone 1 (highest potential) 53/100
32 60175 Saint Charles IL Zone 1 (highest potential) 54/100
33 60140 Hampshire IL Zone 1 (highest potential) 55/100
34 61240 Coal Valley IL Zone 1 (highest potential) 56/100
35 61701 Bloomington IL Zone 1 (highest potential) 57/100
36 60136 Gilberts IL Zone 1 (highest potential) 58/100
37 61752 Le Roy IL Zone 1 (highest potential) 58/100
38 62707 Springfield IL Zone 1 (highest potential) 58/100
39 60120 Elgin IL Zone 1 (highest potential) 59/100
40 60123 Elgin IL Zone 1 (highest potential) 59/100
41 60174 Saint Charles IL Zone 1 (highest potential) 59/100
42 61109 Rockford IL Zone 1 (highest potential) 59/100
43 61016 Cherry Valley IL Zone 1 (highest potential) 60/100
44 62521 Decatur IL Zone 1 (highest potential) 60/100
45 62549 Mt Zion IL Zone 1 (highest potential) 60/100
46 61102 Rockford IL Zone 1 (highest potential) 61/100
47 61108 Rockford IL Zone 1 (highest potential) 61/100
48 61112 Rockford IL Zone 1 (highest potential) 61/100
49 61802 Urbana IL Zone 1 (highest potential) 61/100
50 61925 Dalton City IL Zone 1 (highest potential) 61/100
51 60119 Elburn IL Zone 1 (highest potential) 62/100
52 60502 Aurora IL Zone 1 (highest potential) 62/100
53 61201 Rock Island IL Zone 1 (highest potential) 62/100
54 61822 Champaign IL Zone 1 (highest potential) 62/100
55 61874 Savoy IL Zone 1 (highest potential) 62/100
56 62704 Springfield IL Zone 1 (highest potential) 62/100
57 62711 Springfield IL Zone 1 (highest potential) 62/100
58 60203 Evanston IL Zone 1 (highest potential) 63/100
59 60510 Batavia IL Zone 1 (highest potential) 63/100
60 61036 Galena IL Zone 1 (highest potential) 63/100
61 61801 Urbana IL Zone 1 (highest potential) 63/100
62 60134 Geneva IL Zone 1 (highest potential) 64/100
63 60183 Wasco IL Zone 1 (highest potential) 64/100
64 60505 Aurora IL Zone 1 (highest potential) 64/100
65 61284 Taylor Ridge IL Zone 1 (highest potential) 64/100
66 61820 Champaign IL Zone 1 (highest potential) 64/100
67 62035 Godfrey IL Zone 1 (highest potential) 64/100
68 62052 Jerseyville IL Zone 1 (highest potential) 64/100
69 62301 Quincy IL Zone 1 (highest potential) 64/100
70 62305 Quincy IL Zone 1 (highest potential) 64/100
71 62526 Decatur IL Zone 1 (highest potential) 64/100
72 60504 Aurora IL Zone 1 (highest potential) 65/100
73 60542 North Aurora IL Zone 1 (highest potential) 65/100
74 60554 Sugar Grove IL Zone 1 (highest potential) 65/100
75 61080 South Beloit IL Zone 1 (highest potential) 65/100
76 61853 Mahomet IL Zone 1 (highest potential) 65/100
77 61863 Pesotum IL Zone 1 (highest potential) 65/100
78 61866 Rantoul IL Zone 1 (highest potential) 65/100
79 61880 Tolono IL Zone 1 (highest potential) 65/100
80 62338 Fowler IL Zone 1 (highest potential) 65/100
81 62360 Payson IL Zone 1 (highest potential) 65/100
82 62522 Decatur IL Zone 1 (highest potential) 65/100
83 62561 Riverton IL Zone 1 (highest potential) 65/100
84 62615 Auburn IL Zone 1 (highest potential) 65/100
85 62684 Sherman IL Zone 1 (highest potential) 65/100
86 62703 Springfield IL Zone 1 (highest potential) 65/100
87 60110 Carpentersville IL Zone 1 (highest potential) 66/100
88 60506 Aurora IL Zone 1 (highest potential) 66/100
89 60538 Montgomery IL Zone 1 (highest potential) 66/100
90 61041 Hanover IL Zone 1 (highest potential) 66/100
91 61101 Rockford IL Zone 1 (highest potential) 66/100
92 61107 Rockford IL Zone 1 (highest potential) 66/100
93 61114 Rockford IL Zone 1 (highest potential) 66/100
94 61761 Normal IL Zone 1 (highest potential) 66/100
95 62022 Dow IL Zone 1 (highest potential) 66/100
96 62031 Fieldon IL Zone 1 (highest potential) 66/100
97 62037 Grafton IL Zone 1 (highest potential) 66/100
98 62320 Camp Point IL Zone 1 (highest potential) 66/100
99 62501 Argenta IL Zone 1 (highest potential) 66/100
100 62523 Decatur IL Zone 1 (highest potential) 66/100

Methodology

This ranking is limited to EPA county-level radon zone classification. Zone 1 identifies the highest county-level potential category; it does not measure a home or establish whether any building is above an action level. Within Zone 1, ZIP codes are sub-ranked by Home Safety Score to organize area context.

Data sources: EPA Safe Drinking Water Information System (SDWIS), FEMA National Flood Insurance Program, EPA radon zone maps, EIA electricity rates, and Consumer Confidence Reports. Last updated: 2026-08-31.

Frequently Asked Questions

What is EPA Radon Zone 1?

Zone 1 is the EPA highest county-level radon-potential category. It is not a measurement for a home and cannot determine whether a building is above an action level. A home test is required for that decision.

Should I test for radon?

The EPA recommends testing all homes regardless of radon zone. A DIY test kit costs $15-40. Professional testing costs $150-250. If levels exceed 4 pCi/L, mitigation systems ($800-2,500) can reduce radon by up to 99%.

Explore More Rankings

How this ranking is calculated, data sources, and limitations: Rankings Methodology →

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Disclaimer: Rankings are based on EPA, FEMA, and federal agency data. They reflect historical patterns and risk indicators, not necessarily current conditions. For the most current information, contact your local water utility or request a Consumer Confidence Report.

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