The most recent reported hail day was 2025-09-04, 330 days ago. Knox County is hit in most years, and usually several times over. The largest stone on record here is 2.75 inches, a baseball and 2.8 times the National Weather Service's 1 inch severe criterion, reported on 2011-04-27 near Knoxville.
Colored swath = NOAA MRMS radar-estimated hail size; dots = NOAA SPC reports in Tennessee. Radar-indicated, not a guarantee of damage.
The last hail here fell on 2025-09-04, around Karns. A free SwathIQ account -- hand-reviewed, invite within 24-48h -- pulls Knox County addresses inside a hail swath above your size threshold into a door-knock list you can export, scoped to your approved markets.
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See call-center options ->NOAA's Storm Prediction Center has logged 37 separate hail days here since 2010 -- 2.2 a year over 17 years of record. Those days carry 70 separate reports between them, two or three on a typical one. Exactly one year since 2010 passed with no reported hail day at all. The busiest single year was 2012, with 7 hail days. The last five years track the long-run rate, with 10 days since 2022.
Most hail here stays under 2 inches: only 1 of the 37 days on record passed it, 3%, the last on 2011-04-27. They land in the same month as everything else, April. Golf-ball size is rarer still: 1.75 inches or more on 9 of the 37 days.
Across the whole of Tennessee, see the Tennessee hail map and history.
Reports cluster nearest Knoxville -- 12 of the county's 37 hail days -- then Farragut (11), Powell (5), Karns (4) and Bearden (4). Beyond those, NOAA names Halls, Strawberry Plains, Maloneyville and Lake Forest on more than one hail day apiece.
| Place | Hail days since 2010 | Largest stone |
|---|---|---|
| Knoxville | 7 | 1.75″ |
| Farragut | 5 | 1.75″ |
| Powell | 5 | 1.75″ |
| Karns | 3 | 1.75″ |
| 4 W Karns | 2 | 1.75″ |
The season runs March through July: 32 of the 37 hail days on record fall in those 5 months (86%). April is the single busiest month, with 7 of them (19%). That peak sits inside the window rather than at either end. Hail has also been reported in February, August and September, outside that window. Reports span 8 of the 12 calendar months; the other 4 have never produced one.
| Month | Hail days |
|---|---|
| February | 1 |
| March | 4 |
| April | 7 |
| May | 7 |
| June | 7 |
| July | 7 |
| August | 3 |
| September | 1 |
That day put 6 reports on the map, the biggest 1.75 inches near Karns. No hail day has been reported here yet this year.
| Date | Max hail | Reports |
|---|---|---|
| 2025-09-04 | 1.75″ | 6 |
| 2025-04-10 | 1.75″ | 6 |
| 2024-05-26 | 1.75″ | 3 |
| 2023-08-12 | 1.00″ | 2 |
| 2023-07-02 | 1.00″ | 1 |
| 2023-06-11 | 1.00″ | 1 |
| 2023-06-05 | 1.00″ | 1 |
| 2023-05-16 | 1.00″ | 3 |
The colored swath is NOAA's MRMS radar estimate of the largest hail per ~1 km cell; the dots are SPC ground reports. Yellow is about an inch, red 1.5 to 2″, purple 2″ and up (hail size vs roof damage). On this county's worst day the reports reached 2.75 inches, which is the purple band. Look up a street address with the hail history by address tool.
The nearest counties with a page of their own: Anderson County (19 hail days), Blount County (26) and Loudon County (14). Knox County takes more hail than any of them.
Anderson County · Blount County · Loudon County
Back to the Tennessee hail map or the U.S. hail map.
Data & method: NOAA/NWS Storm Prediction Center reports + NOAA MRMS MESH radar, Knox County, Tennessee only. Radar-indicated and observation-based -- informational only, not a guarantee of damage or a valid claim.