Jefferson County was hit as recently as 2026-05-16, 76 days ago. Jefferson County is hit in most years. The largest stone on record here is 1.75 inches, a golf ball and 1.8 times the National Weather Service's 1 inch severe criterion, reported on 2026-05-16 near Dix.
Colored swath = NOAA MRMS radar-estimated hail size; dots = NOAA SPC reports in Illinois. Radar-indicated, not a guarantee of damage.
The last hail here fell on 2026-05-16, around Dix. A free SwathIQ account -- hand-reviewed, invite within 24-48h -- pulls Jefferson 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 18 separate hail days here since 2010 -- 1.1 a year over 17 years of record. They carry 27 reports in total: most hail days here are logged from a single spot. 5 of those 17 years produced none at all. The busiest single year was 2012, with 3 hail days. The last five years track the long-run rate, with 5 days since 2022.
No stone of 2 inches or more has ever been reported in Jefferson County: all 18 hail days on record topped out below that. Golf-ball size is rarer still: 1.75 inches or more on 2 of the 18 days.
Across the whole of Illinois, see the Illinois hail map and history.
Reports cluster nearest Mount Vernon -- 10 of the county's 18 hail days -- then Dix (4) and Woodlawn (4). That one town is named on 56% of them.
| Place | Hail days since 2010 | Largest stone |
|---|---|---|
| Mount Vernon | 7 | 1.50″ |
| Woodlawn | 3 | 1.50″ |
| Dix | 2 | 1.50″ |
| 1 SW Mount Vernon | 2 | 1.00″ |
| 3 SSE Dix | 1 | 1.75″ |
The season runs March through June: 16 of the 18 hail days on record fall in those 4 months (89%). May is the single busiest month, with 6 of them (33%). That peak sits inside the window rather than at either end. Hail has also been reported in January and July, outside that window. Reports span 6 of the 12 calendar months; the other 6 have never produced one.
| Month | Hail days |
|---|---|
| January | 1 |
| March | 4 |
| April | 4 |
| May | 6 |
| June | 2 |
| July | 1 |
That day put 2 reports on the map, the biggest 1.75 inches near Dix. 2 hail days have already been reported this year.
| Date | Max hail | Reports |
|---|---|---|
| 2026-05-16 | 1.75″ | 2 |
| 2026-04-27 | 1.00″ | 1 |
| 2025-03-30 | 1.00″ | 1 |
| 2024-04-18 | 1.25″ | 2 |
| 2024-03-14 | 1.00″ | 3 |
| 2021-05-06 | 1.00″ | 1 |
| 2020-03-12 | 1.25″ | 1 |
| 2019-06-16 | 1.00″ | 1 |
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 1.75 inches, which is the red band. Look up a street address with the hail history by address tool.
The nearest counties with a page of their own: Marion County (21 hail days), Franklin County (24) and Washington County (18). Jefferson County sits in between.
Marion County · Franklin County · Washington County
Back to the Illinois hail map or the U.S. hail map.
Data & method: NOAA/NWS Storm Prediction Center reports + NOAA MRMS MESH radar, Jefferson County, Illinois only. Radar-indicated and observation-based -- informational only, not a guarantee of damage or a valid claim.