ZIP 78646 is served primarily by Williamson County, TX — including Round Rock. ZIP-level data is sparse — showing the Williamson County aggregate. FEMA NRI rates wildfire risk here as Very High.
Jan peaks. Dec dips. ZIP-level seasonality is sparse — this is the county aggregate.
Top 5 NFIRS incident types — county-level breakdown.
| # | Incident type | Count | Share | |
|---|---|---|---|---|
| 1 | Gas leak (natural gas or LPG) | 549 | 22.2% | |
| 2 | Building fires | 204 | 8.3% | |
| 3 | Grass fire | 172 | 7.0% | |
| 4 | Authorized controlled burning | 168 | 6.8% | |
| 5 | Unauthorized burning | 148 | 6.0% |
16 cities sit in Williamson County. Click for the per-city NFIRS profile.
| # | City | Population | 2025 incidents | Building fires | Grade |
|---|---|---|---|---|---|
| 1 | Round Rock | 120,465 | 396 | 25 | A |
| 2 | Cedar Park | 76,344 | 251 | 47 | A |
| 3 | Georgetown | 71,788 | 573 | 28 | B |
| 4 | Leander | 62,491 | 335 | 28 | B+ |
| 5 | Hutto | 29,498 | 210 | 18 | A- |
| 6 | Brushy Creek | 22,282 | 0 | 0 | A+ |
| 7 | Taylor | 16,449 | 214 | 24 | B- |
| 8 | Sonterra | 8,082 | 0 | 0 | — |
| 9 | Liberty Hill | 5,265 | 211 | 14 | D |
| 10 | Santa Rita Ranch | 3,655 | 0 | 0 | — |
| 11 | Jarrell | 2,132 | 105 | 5 | C |
| 12 | Serenada | 1,695 | 0 | 0 | — |
| 13 | Bartlett | 1,495 | 34 | 6 | C+ |
| 14 | Granger | 1,100 | 4 | 2 | B+ |
| 15 | Florence | 1,017 | 54 | 3 | C- |
| 16 | Thrall | 797 | 27 | 1 | C |
Some ZIPs span multiple counties. The primary above is the largest by population weight; secondary counties are below.
| County | State | Weight | |
|---|---|---|---|
| Travis County | TX | 0.50 | FIPS 48453 |
The figures above are historical. For today's air quality, fire-weather warnings, and active fires, go to the official sources.
This ZIP doesn't have enough NFIRS coverage on its own (under 10 reported incidents across 2021–2025) to publish ZIP-level statistics, so we're showing the Williamson County aggregate above. NFIRS reporting is voluntary and many rural ZIPs roll up to broader county totals. The ZIP-to-county mapping uses SimpleMaps' uscities.zips dataset.