Hail history for Rock Valley, Iowa
NOAA hail reports in and within about 5 km (3 miles) of Rock Valley since 1996, with preliminary reports to November 3, 2026.
Readout · Rock Valley
- Last hail
- Jun 28, 2026
- 0.75 in, penny size
- Hail days, last 5 years
- 3
- since Nov 3, 2021 · 3 reports
- Largest ever
- 1.75 in
- golf ball · Jul 9, 2009
34 reports on 22 days since 1996 · #56 of 483 Iowa places
Hail map · Rock Valley
- Under 1 in
- 1–1.75 in
- 1.75–2.5 in
- 2.5–4 in
- 4 in +
- No size
For homeowners
Roof damage after hail? Get a free inspection
Hail bruises shingles and cracks seals in ways you can't see from the ground, and most insurers set a claim deadline after the storm. The latest hail report in Rock Valley is from June 28, 2026. A local roofer can check and document it at no cost.
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What the record says about Rock Valley
The latest hail report in and around Rock Valley is from June 28, 2026, 0.75 in (penny size). Since November 3, 2021 there have been 3 separate hail days; the biggest stones in that time were 1.00 in on April 19, 2023.
Over the 20 years 2006–2025, Rock Valley logged 20 reports on 10 hail days, about 1.0 reports a year. That is about twice the median Iowa town on this site (0.5 a year) and ranks #56 of 483 Iowa cities and towns on this site for all-time reports. Rock Valley accounts for 13% of the 269 reports filed in Sioux County.
0% of reports with a size were 2 inches (hen egg) or larger, against 6% for the median Iowa town on this site. The largest hail on record here is 1.75 in (golf ball) on July 9, 2009 near 3.32 WSW Rock Vly.
Reports were down 75% in 2016–2025 (4) compared with 2006–2015 (16). The busiest year was 2007, with 6 reports on 2 days. Hail here peaks in June (35% of reports); 53% fall between April and June.
Reports a year 2006–2025 average
- Rock Valley 1.0
- Sioux County 6.8
- Median Iowa town on this site 0.5
Hail days 2006–2025
- Rock Valley 10
- Sioux County 66
- Median Iowa town on this site 7
Share 2 in or larger of sized reports
- Rock Valley 0%
- Sioux County 6%
- Median Iowa town on this site 6%
Hail over time
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026 | 1 | 1 | 2 | ||||||||||
| 2025 | 0 | ||||||||||||
| 2024 | 0 | ||||||||||||
| 2023 | 1 | 1 | |||||||||||
| 2022 | 0 | ||||||||||||
| 2021 | 1 | 1 | |||||||||||
| 2020 | 0 | ||||||||||||
| 2019 | 0 | ||||||||||||
| 2018 | 2 | 2 | |||||||||||
| 2017 | 0 |
Hail days since Nov 3, 2021
| Date | Reports | Largest | Storm page |
|---|---|---|---|
| Jun 28, 2026 | 1 | 0.75 in | — |
| May 17, 2026 | 1 | 0.75 in | — |
| Apr 19, 2023 | 1 | 1.00 in | — |
Largest hail on record
| Date | Size | Location | County | Time · source |
|---|---|---|---|---|
| Jul 9, 2009 | 1.75 ingolf ball | 3.32 WSW Rock Vly | Sioux | 18:15 local · NCEI |
| Jul 9, 2009 | 1.75 ingolf ball | Rock Vly | Sioux | 13:05 local · NCEI |
| Jun 10, 2007 | 1.75 ingolf ball | Rock Vly | Sioux | 15:08 local · NCEI |
| Jun 10, 2007 | 1.75 ingolf ball | 4 N Rock Vly | Sioux | 15:00 local · NCEI |
| Jun 12, 2001 | 1.75 ingolf ball | Rock Vly | Sioux | 18:15 local · NCEI |
Size of every report
- Under 1 in 10 29%
- 1–2 in 24 71%
- 2 in + 0 0%
Most recent reports
| Date | Size | Location | County | Damage | Time · source |
|---|---|---|---|---|---|
| Jun 28, 2026 | 0.75 inpenny | Rock Vly | Sioux | — | 04:24 local · NCEI |
| May 17, 2026 | 0.75 inpenny | Rock Vly | Sioux | — | 16:51 local · NCEI |
| Apr 19, 2023 | 1.00 inquarter | 0.5 E Rock Vly | Sioux | — | 20:11 local · NCEI |
| Aug 27, 2021 | 1.00 inquarter | 2.13 SSE Rock Vly | Sioux | $10K | 00:05 local · NCEI |
| Aug 28, 2018 | 0.88 innickel | 0.5 E Rock Vly | Sioux | — | 03:37 local · NCEI |
| Aug 28, 2018 | 1.00 inquarter | Rock Vly | Sioux | — | 03:36 local · NCEI |
| Jun 16, 2014 | 1.25 inhalf dollar | Rock Vly | Sioux | — | 12:30 local · NCEI |
| May 4, 2012 | 1.00 inquarter | 2.44 NW Perkins | Sioux | — | 20:45 local · NCEI |
| May 4, 2012 | 1.25 inhalf dollar | Rock Vly | Sioux | — | 20:36 local · NCEI |
| Sep 22, 2010 | 1.00 inquarter | Rock Vly | Sioux | — | 14:14 local · NCEI |
| Sep 22, 2010 | 1.00 inquarter | 3.74 SW Rock Vly | Sioux | — | 12:00 local · NCEI |
| Aug 19, 2009 | 0.75 inpenny | 3.77 SSW Rock Vly | Sioux | — | 16:40 local · NCEI |
Hail history near Rock Valley
- Doon 10 km · 17
- Hull 13 km · 12
- Sioux Center 17 km · 27
- Inwood 17 km · 13
- Boyden 23 km · 13
- Rock Rapids 27 km · 29
- Hawarden 27 km · 26
- Lester 27 km · 16
Questions about hail in Rock Valley
How often does it hail in Rock Valley, Iowa?
34 hail reports have been logged in and within about 5 km (3 miles) of Rock Valley since 1996. Over the 20 years 2006–2025 that averages 1.0 reports a year. That ranks #56 of 483 Iowa places by number of reports.
When is hail season in Rock Valley?
Most reports come in June, August, July. June alone accounts for 35% of all reports.
What is the largest hail recorded in Rock Valley?
1.75 in (golf ball size) on July 9, 2009 near 3.32 WSW Rock Vly. 0% of reports here were 2 inches or larger.
When did it last hail in Rock Valley?
The most recent report in this data is from June 28, 2026 (0.75 in). Final NOAA data runs to July 31, 2026; preliminary NWS reports run to November 3, 2026.
How many hail storms has Rock Valley had in the last five years?
3 separate days with hail reports since November 3, 2021, adding up to 3 reports. The most recent was June 28, 2026.
Where does this hail data come from?
Hail reports come from the NOAA NCEI Storm Events Database, which the National Weather Service compiles from spotter, public, law enforcement and media reports. Recent days use preliminary NWS Local Storm Reports via the Iowa Environmental Mesonet until NOAA publishes final data. Only reported hail is counted, so areas with fewer people tend to have fewer reports.