Hail History

Hail history for Alton, Iowa

NOAA hail reports in and within about 5 km (3 miles) of Alton since 1979, with preliminary reports to November 3, 2026.

Readout · Alton

Last hail
Aug 28, 2018
1.50 in, ping pong ball size
Hail days, last 5 years
0
since Nov 3, 2021 · 0 reports
Largest ever
1.75 in
golf ball · Aug 27, 2018

21 reports on 14 days since 1979 · #144 of 483 Iowa places

Hail map · Alton

Alton Orange City Granville Hospers Sioux Center Boyden Sheldon 10 mi
  • Under 1 in
  • 1–1.75 in
  • 1.75–2.5 in
  • 2.5–4 in
  • 4 in +
  • No size
21 most recent reports with a location; Sioux County is shaded. Open street map

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What the record says about Alton

The latest hail report in and around Alton is from August 28, 2018, 1.50 in (ping pong ball size). There has been no hail report here in the five years since November 3, 2021.

Over the 20 years 2006–2025, Alton logged 12 reports on 7 hail days, about 0.6 reports a year. That is 33% more than the median Iowa town on this site (0.5 a year) and ranks #144 of 483 Iowa cities and towns on this site for all-time reports. Alton accounts for 8% 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 August 27, 2018 near 1.22 NW Granville.

Reports were down 50% in 2016–2025 (4) compared with 2006–2015 (8). The busiest year was 2012, with 5 reports on 2 days. Hail here peaks in July (33% of reports); 29% fall between April and June.

Reports a year 2006–2025 average

  • Alton 0.6
  • Sioux County 6.8
  • Median Iowa town on this site 0.5

Hail days 2006–2025

  • Alton 7
  • Sioux County 66
  • Median Iowa town on this site 7

Share 2 in or larger of sized reports

  • Alton 0%
  • Sioux County 6%
  • Median Iowa town on this site 6%

Hail over time

0246 1979: 1 reports, largest 1.75 in 1980 1983: 1 reports, largest 1.75 in 1990 2000: 1 reports, largest 0.88 in 2000 2001: 2 reports, largest 1.75 in 2002: 1 reports, largest 0.75 in 2004: 3 reports, largest 0.88 in 2007: 1 reports, largest 1.00 in 2010: 1 reports, largest 0.75 in 2010 2012: 5 reports, largest 1.75 in 2014: 1 reports, largest 1.00 in 2018: 4 reports, largest 1.75 in 2020
Reports per year, 1979–2026. Bar colour shows the largest hail that year. Reporting grew sharply after the mid-1990s, so early decades undercount.
02468 Jan Feb Mar April: 1 reports (5%) Apr May: 1 reports (5%) May June: 4 reports (19%) Jun July: 7 reports (33%) Jul August: 7 reports (33%) Aug September: 1 reports (5%) Sep Oct Nov Dec
All 21 reports by calendar month.
Reports per month, 2017–2026. Darker cells had more reports.
YearJanFebMarAprMayJunJulAugSepOctNovDecTotal
2026 0
2025 0
2024 0
2023 0
2022 0
2021 0
2020 0
2019 0
2018 4 4
2017 0

Largest hail on record

Largest hail reports in Alton
Date Size Location County Time · source
Aug 27, 2018 1.75 ingolf ball 1.22 NW Granville Sioux 14:39 local · NCEI
Jul 25, 2012 1.75 ingolf ball 2.31 NNE Alton Sioux 16:18 local · NCEI
Jun 11, 2001 1.75 ingolf ball Granville Sioux 20:05 local · NCEI
Sep 5, 1983 1.75 ingolf ball — Sioux 17:05 local · NCEI
Aug 20, 1979 1.75 ingolf ball — Sioux 16:20 local · NCEI

Sizes filed before 1996 are often rough estimates (round numbers like 7.00 or 8.00 in) without an exact spot; they are shown as NOAA filed them.

Size of every report

Most recent reports

Most recent hail reports in Alton
Date Size Location County Time · source
Aug 28, 2018 1.50 inping pong ball 1.67 WNW Granville Sioux 04:15 local · NCEI
Aug 27, 2018 1.25 inhalf dollar 1.67 ENE Alton Sioux 14:39 local · NCEI
Aug 27, 2018 1.75 ingolf ball 1.22 NW Granville Sioux 14:39 local · NCEI
Aug 27, 2018 1.00 inquarter 1.47 SSW Alton Sioux 14:33 local · NCEI
Jun 16, 2014 1.00 inquarter 0.51 E Alton Sioux 12:35 local · NCEI
Aug 8, 2012 0.75 inpenny 0.86 NW Alton Sioux 10:07 local · NCEI
Jul 25, 2012 1.00 inquarter 2.05 NW Granville Sioux 16:22 local · NCEI
Jul 25, 2012 1.50 inping pong ball 2.57 NW Granville Sioux 16:20 local · NCEI
Jul 25, 2012 1.75 ingolf ball 2.31 NNE Alton Sioux 16:18 local · NCEI
Jul 25, 2012 1.25 inhalf dollar 3.15 NNE Alton Sioux 16:15 local · NCEI
Apr 24, 2010 0.75 inpenny 0.86 NW Alton Sioux 17:44 local · NCEI
Jul 26, 2007 1.00 inquarter Alton Sioux 18:15 local · NCEI

Hail history near Alton

Questions about hail in Alton

How often does it hail in Alton, Iowa?

21 hail reports have been logged in and within about 5 km (3 miles) of Alton since 1979. Over the 20 years 2006–2025 that averages 0.6 reports a year. That ranks #144 of 483 Iowa places by number of reports.

When is hail season in Alton?

Most reports come in July, August, June. July alone accounts for 33% of all reports.

What is the largest hail recorded in Alton?

1.75 in (golf ball size) on August 27, 2018 near 1.22 NW Granville. 0% of reports here were 2 inches or larger.

When did it last hail in Alton?

The most recent report in this data is from August 28, 2018 (1.50 in). Final NOAA data runs to July 31, 2026; preliminary NWS reports run to November 3, 2026.

How many hail storms has Alton had in the last five years?

None: there has been no hail report in and within about 5 km (3 miles) of Alton since November 3, 2021. The last one was on August 28, 2018.

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.