Hail history for Jefferson County, IA

Jefferson County has 93 recorded hail events in the NOAA Storm Events Database — 55 of them 1″ or larger and 3 at 2″ or larger. The largest on record: 3.75″ (softball) on June 28, 1976.

Records 1950–present Data through April 2026 Peak month April

Core sample · every recorded event, 1955–2026

Mark size = measured hail diameter; slivers are events with no recorded size. Amber ≥2″, red ≥2.75″ (baseball class). Denser recent decades partly reflect better reporting, not only more storms.

Recorded events 93 since 1960

1″ or larger 55 NWS severe threshold

2″ or larger 3 hen egg class and up

Largest recorded 3.75″ softball · June 28, 1976

Read the record honestly: Storm Events contains what was reported to the National Weather Service. Sparse or rural counties under-report, and coverage improved sharply after the mid-1990s — a quiet-looking stretch is not proof nothing fell.

When it hails in Jefferson County

Recorded events by month, 1950–present. The amber bar marks Jefferson County's peak: April.

Most recent recorded events

Latest 8 of 93 recorded events · data through April 2026
Date	Size	Comparable to
April 14, 2026	1.0″	Quarter
April 14, 2026	2.0″	Hen egg
March 10, 2026	1.0″	Quarter
March 10, 2026	1.0″	Quarter
March 10, 2026	1.5″	Ping-pong ball
October 24, 2024	0.75″	Penny
May 7, 2023	1.75″	Golf ball
May 6, 2023	1.25″	Half dollar

Looking for a specific storm? Use the did-it-hail date lookup for Jefferson County.

From the storm reports

Narratives as filed with the NOAA Storm Events Database (public records; lightly trimmed for length).

April 14, 2026 · 2.0″ (hen egg)

The time was estimated from radar data.

May 17, 2017 · 1.75″ (golf ball)

The spotter reported hail lasted 10 minutes and covered the ground.

Events by decade

1950s	1960s	1970s	1980s	1990s	2000s	2010s	2020s
0	3	2	3	4	33	35	13

The climb across decades is largely a reporting story: spotter networks, radar, and digital filing pulled far more storms into the record after the 1990s.

Questions about hail in Jefferson County

Has it ever hailed in Jefferson County?

Yes — 93 hail events have been recorded for Jefferson County, IA in the NOAA Storm Events Database since 1960, including 55 of 1″ (quarter size) or larger.

When did it last hail in Jefferson County?

The most recent recorded hail event for Jefferson County, IA is April 14, 2026, with 1.0″ (quarter) hail. The database is currently updated through April 2026, so a storm from the last few weeks may not appear yet. To check a specific day, use the did-it-hail date lookup.

What is the largest hail ever recorded in Jefferson County?

3.75″ (softball), recorded on June 28, 1976. Hail that size is destructive-class and typically damages roofs, vehicles, and siding. See how big that really is on the actual-size hail chart.

Does a recorded hail event mean my roof was damaged?

No. This page reports storm records, not damage. Hail size and damage vary block by block within a county, and only an inspection can establish what happened to a specific roof. If you suspect damage, talk to your insurer or a licensed roofer — they can pull the same NOAA records for your claim.

More Iowa hail history

All 99 Iowa counties, ranked by recorded hail →

Source: NOAA/NCEI Storm Events Database, public domain, updated monthly by NCEI — this site's copy runs through April 2026. HailHistory reports records; it does not give insurance advice or assess damage.