Tornadoes · United States · Iowa · 2026

EF1 tornado, Franklin County, Iowa, July 20, 2026

Name: EF1 tornado, Franklin County, Iowa, July 20, 2026
Start: 2026-07-20T20:35:00.000Z
Location: Franklin County, Iowa

This EF1 tornado ran 0.4 miles across Franklin County on July 20, 2026, touching down at 3:35 PM CDT and reaching 25 yards wide. It killed nobody.

Preliminary. This is NWS DMX's damage survey, filed in the Damage Assessment Toolkit. The rating, the path and the casualties are the survey's and can change while it is revised. The Storm Prediction Center compiles the official record of 2026 from these surveys and publishes it in the spring of 2027; this page moves to that tornado's permanent address when it does.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 mph
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 mph
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The survey

Rating, as surveyed: EF1, preliminary
Date: July 20, 2026
Touchdown: 3:35 PM CDT (20:35 UTC)
Path length: 0.4 miles (0.6 km)
Path width: 25 yards (23 m)
Deaths: 0
Injuries: 0
County: Franklin County
Touchdown point: 42.834, -93.222
Lift-off point: 42.834, -93.215
Highest wind the damage implies: 110 mph
Surveyed by: NWS DMX
Survey last edited: July 24, 2026
Record number: None yet. SPC numbers 2026 in the spring of 2027.

What the survey found

Intermittent tornado path that produced damage to roof of home along with convergent signature in the corn field.

Written by NWS DMX in the NWS Damage Assessment Toolkit. A survey is revised as better evidence arrives.

The damage survey

3 damage points were recorded along this path by NWS DMX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EFU. The highest wind the damage implies is 110 mph.

Convergent pattern in corn field.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

The county was under a tornado watch, issued at 20:05 UTC and running to 23:17 UTC.

Issued (UTC)	Expired	Product	Office
17:00 UTC	21:00 UTC	Heat Advisory	DMX
19:51 UTC	20:30 UTC	Severe Thunderstorm Warning	DMX
20:05 UTC	23:17 UTC	Tornado Watch	DMX
20:23 UTC	21:30 UTC	Severe Thunderstorm Warning	DMX
20:24 UTC	21:08 UTC	Severe Thunderstorm Warning	DMX
20:57 UTC	21:10 UTC	Tornado Warning	DMX

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The forecast that day

The Storm Prediction Center had this point in a Enhanced Risk, with a 0.05 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:57 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

What forecasters said that day

The local office's own words before the tornado touched down, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Des Moines, IA wrote its last area forecast discussion before the tornado touched down at Jul 20, 2:34 PM CDT, 1 hour 1 minute earlier. Its key messages:

A Heat Advisory is in effect this afternoon with heat indices from 100-110F expected.
Strong to severe storms are forecast from this afternoon through the overnight, beginning in northern Iowa and making it to southern Iowa by early Tuesday morning. All severe hazards are possible.
Relief from the heat starts Tuesday and lasts through the work week before another warmup this weekend.

Area forecast discussion, Jul 20, 2:34 PM CDT, 1 hour 1 minute before

Area Forecast Discussion
National Weather Service Des Moines IA
234 PM CDT Mon Jul 20 2026

.KEY MESSAGES...

- A Heat Advisory is in effect this afternoon with heat indices
  from 100-110F expected.

- Strong to severe storms are forecast from this afternoon
  through the overnight, beginning in northern Iowa and making
  it to southern Iowa by early Tuesday morning. All severe
  hazards are possible.

- Relief from the heat starts Tuesday and lasts through the work
  week before another warmup this weekend.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 226 PM CDT Mon Jul 20 2026

A classic July NW flow severe weather setup is in store for todays
enhanced risk across Iowa. A stacked 500mb trough and surface low is
currently approaching Lake Superior and the trailing cold front
through Minnesota to South Dakota will be our main storm initiation
mechanism today.

To the dismay of most of the recent CAMs, a few storms are already
forming along the cold front in southern Minnesota, though these are
elevated and the main show is likely to hold off until the boundary
layer continues to destabilize. Speaking of destabilizing, the heat
today is well underway as the grand finale of the past week of heat.
Between the expected highs in the mid 90s and dewpoints in the mid
70s, heat indices across a large part of the state are expected
to be between 100-110F. Many stations across central Iowa
already have an index over 100F, but mixing out of moisture may
keep them from surging too much higher. This will lead to a
large zone of 3500+ J/kg of CAPE across north central Iowa as
the cold front crosses the state. Hodographs are generally
supportive of supercells, particularly further east near the
warm front, with decent mid level shear and low level turning.
Around mid to late afternoon, early convection along the cold
front will have the best chance at briefly supercell mode,
capable of large hail and gusty winds. 3CAPE, 0-1 SRH, and
vorticity will all be most favorable for a tornado or two near
the warm front (likely in or near ARX's CWA), though a powerful
updraft sitting on the cold front could be capable of producing
a tornado. The relatively large T/Td spreads and strong DCAPE
could transition the threat quickly to a more linear mode, and
damaging wind would then be the main threat. There is still
large uncertainty in storm coverage across the cold front this
afternoon. There is a scenario where initiation holds off until
mid evening, and another where elevated convection in MN
continues to intensify and establishes itself early as it
crosses into Iowa.

Storms into this evening and overnight will be dependent on how cold
pools are established this afternoon. Convection will likely
continue to develop this evening as the increasing LLJ overruns any
remnant cold pools and the cold front meanders over central Iowa. A
mainly damaging wind threat and perhaps large hail threat will be
associated with these storms through the evening and overnight.
Additionally, PWATs near 2" and some potential for training
thunderstorms would make for a higher flash flooding threat, though
this threat will be muted by the low soil moisture and mature crops.

Any remaining storms will likely clear out of southern Iowa by early
morning and give way to dry conditions on Tuesday. Relief from the
heat will finally arrive Tuesday with highs in the low to mid 80s.
Winds will stay quite breezy behind the cold front with gusts up to
30-35 mph in the afternoon. Additionally, the HRRR smoke guidance is
forecasting smoke to linger through the day tomorrow, even at the
surface, though it likely will be a bit improved from this morning.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 226 PM CDT Mon Jul 20 2026

More mild conditions are expected through the end of the work week
with highs in the upper 70s and 80s across the state. Continued
ridging out to our south and west will continue, but there is decent
signal for more shortwaves Wednesday into Thursday that could bring
in additional chances for showers and storms. Severe weather is less
likely with these storm chances, as moisture will be limited, but
more details will be sorted out in the coming days. The ridge is
again expected to intensify over the central plains during the
weekend and heat will likely return by Saturday and Sunday.
Continued NW flow could bring in a marginal chances for smoke
haze since wildfires are still ongoing in Canada.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1234 PM CDT Mon Jul 20 2026

VFR TAFs are occurring across all TAF sites with the 18Z
issuance. This morning's showers have moved off to the east but
lingering low clouds still exist across the eastern terminals.
There's forecast to be a lull in activity before a cold front
drops southeast through Iowa later this afternoon through the
overnight. Beginning at KMCW roughly 20Z and working south
through the TAF period. The fast moving front will bring
categorical reductions to TAF sites for a couple hours before
moving out. Expect gusty and erratic winds and category
reduction due to showers and storms. The front is forecast to be
through KOTM by 10Z. Behind the departing front, wildfire smoke
is progged to move back into the area bringing potential for
VSBY reductions through the rest of the TAF window. Also, strong
northwesterly winds are expected to develop late Tuesday
morning.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM CDT this evening for IAZ004>007-
015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097.

&&

SHORT TERM...De Bruin
LONG TERM...De Bruin
AVIATION...Vorst

Hazardous weather outlook, Jul 20, 2:38 PM CDT, 57 minutes before

Hazardous Weather Outlook
National Weather Service Des Moines IA
238 PM CDT Mon Jul 20 2026

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-
081>086-092>097-211945-
Emmet-Kossuth-Winnebago-Worth-Palo Alto-Hancock-Cerro Gordo-
Pocahontas-Humboldt-Wright-Franklin-Butler-Bremer-Sac-Calhoun-
Webster-Hamilton-Hardin-Grundy-Black Hawk-Crawford-Carroll-Greene-
Boone-Story-Marshall-Tama-Audubon-Guthrie-Dallas-Polk-Jasper-
Poweshiek-Cass-Adair-Madison-Warren-Marion-Mahaska-Adams-Union-
Clarke-Lucas-Monroe-Wapello-Taylor-Ringgold-Decatur-Wayne-
Appanoose-Davis-
238 PM CDT Mon Jul 20 2026

This Hazardous Weather Outlook is for portions of central Iowa.

.DAY ONE...This afternoon and tonight

A Heat Advisory is in effect for the area today. Please refer to
the National Weather Service website at weather.gov/desmoines for
further details.

Strong to severe thunderstorms are possible this afternoon into
tonight with an Enhanced Risk (level 3 of 5) for severe storms.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Additional thunderstorms are possible Wednesday night into
Thursday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed today.

67

In the hours before

Local storm report, Jul 20, 3:01 PM CDT, 34 minutes before

Preliminary Local Storm Report
National Weather Service Des Moines IA
301 PM CDT Mon Jul 20 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0248 PM     Tstm Wnd Dmg     Algona                  43.08N 94.24W
07/20/2026                   Kossuth            IA   Emergency Mngr

            Emergency manager reports tree branch
            snapped in Algona. Time estimated from
            radar.

&&

67

Local storm report, Jul 20, 3:04 PM CDT, 31 minutes before

Preliminary Local Storm Report
National Weather Service Des Moines IA
304 PM CDT Mon Jul 20 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0248 PM     Tstm Wnd Dmg     Algona                  43.08N 94.24W
07/20/2026                   Kossuth            IA   Emergency Mngr

            Emergency manager reports tree limbs down
            across residential street. Time estimated
            from radar.

&&

67

Local storm report, Jul 20, 3:11 PM CDT, 24 minutes before

Preliminary Local Storm Report
National Weather Service Des Moines IA
311 PM CDT Mon Jul 20 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0246 PM     Tstm Wnd Gst     4 SW Burt               43.16N 94.29W
07/20/2026  M63 MPH          Kossuth            IA   Mesonet

            Measured from personal weather station.

&&

67

Local storm report, Jul 20, 3:12 PM CDT, 23 minutes before

Preliminary Local Storm Report
National Weather Service Des Moines IA
312 PM CDT Mon Jul 20 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0311 PM     Tstm Wnd Gst     4 NW Lone Rock          43.26N 94.37W
07/20/2026  M63 MPH          Kossuth            IA   Mesonet

            Measured from personal weather station.

&&

67

Local storm report, Jul 20, 3:25 PM CDT, 10 minutes before

Preliminary Local Storm Report
National Weather Service Des Moines IA
325 PM CDT Mon Jul 20 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0252 PM     Tstm Wnd Dmg     7 SSE Rock Falls        43.12N 93.03W
07/20/2026                   Cerro Gordo        IA   Law Enforcement

            Report of a semi tractor trailer and pickup
            trick with attached trailer flipped on US-18
            along Cerro Gordo/Floyd Co. lines. Time
            estimated from radar.

&&

67

The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Minneapolis, MN (KMPX), 12:00Z

8.6 hours before the tornado, 226 km from the path. July 20, 2026.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.

Mixed-layer CAPE: 982 J/kg
Mixed-layer CIN: -242 J/kg
Surface CAPE: 222 J/kg
Mixed-layer LCL: 1013 m above ground
0-6 km bulk shear: 50 kt
0-1 km bulk shear: 24 kt
0-1 km storm-relative helicity: 299 m²/s²
0-3 km storm-relative helicity: 288 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.2
0-3 km lapse rate: 3.2 K/km

Open this sounding in Storm Lab

Minneapolis, MN (KMPX), 00:00Z

3.4 hours after it, 226 km from the path. July 21, 2026.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.

Hodograph

Mixed-layer CAPE: 256 J/kg
Mixed-layer CIN: -208 J/kg
Surface CAPE: 948 J/kg
Mixed-layer LCL: 1707 m above ground
0-6 km bulk shear: 62 kt
0-1 km bulk shear: 15 kt
0-1 km storm-relative helicity: 50 m²/s²
0-3 km storm-relative helicity: 139 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4
0-3 km lapse rate: 6.4 K/km

Open this sounding in Storm Lab

The surface observations

Hampton (HPT), 13 km from the path, in the two hours either side.

Time (UTC)	Temp (°F)	Dew point (°F)	Wind	Gust (kt)	Pressure (mb)	Weather
18:35 UTC	80.6	73.4	170° 9 kt		1009.5
18:55 UTC	80.6	75.2	170° 12 kt	15	1008.8
19:15 UTC	82.4	77	160° 7 kt		1008.8
19:35 UTC	84.2	77	200° 10 kt	15	1008.5
19:55 UTC	86	78.8	190° 13 kt	20	1006.8
20:15 UTC	84.2	77	190° 12 kt	18	1005.4
20:35 UTC	82.4	77	240° 8 kt	18	1007.8
20:55 UTC	64.4	64.4	10° 12 kt	23	1009.8	+RA
21:15 UTC	68	66.2	270° 8 kt	22	1007.5	-RA
21:35 UTC	68	68	220° 13 kt		1007.1
21:55 UTC	69.8	69.8	240° 10 kt	16	1007.8
22:15 UTC	71.6	71.6	240° 6 kt		1007.8

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Des Moines radar (KDMX), 129 km away, was scanning. The volume nearest the touchdown began at 20:34 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)	Report	Where	County	Remark
19:52 UTC	TSTM WND DMG	7 Sse Rock Falls	Cerro Gordo, IA	Report of a semi tractor trailer and pickup trick with attached trailer flipped on US-18 along Cerro Gordo/Floyd Co. lines. Time estimated from radar.
19:54 UTC	TSTM WND GST 65	Nora Springs	Floyd, IA
20:01 UTC	TSTM WND DMG	2 Sse Nora Springs	Floyd, IA	* 1 INJ * Updates previous tstm wnd dmg report from 2 SSE Nora Springs. Multiple vehicles and tractor trailers blown over on Avenue of the Saints/ US-18 between MM 195 and 196. EM reported 1 injury.
20:01 UTC	TSTM WND DMG	2 Sse Nora Springs	Floyd, IA	Multiple vehicles and tractor trailers blown over on Avenue of the Saints/ US-18 between MM 195 and 196.
20:03 UTC	TSTM WND DMG	3 Sw Britt	Hancock, IA	Emergency manager shared photos of power pole damage along 210th st. in Hancock county. Time esatimted from radar.
20:25 UTC	TSTM WND DMG	Belmond	Wright, IA	Multiple trees down via slack. Time estimated via radar.
20:35 UTC	TSTM WND GST 62	6 Wnw Belmond	Wright, IA	Measured by personal weather station.
20:38 UTC	TSTM WND DMG	4 S Sheffield	Franklin, IA	Several trees down along with roof damage. Time estimated via radar.
20:40 UTC	TSTM WND GST 80	4 S Sheffield	Franklin, IA	Relayed by emergency manager. Time estimated from radar.
20:41 UTC	TSTM WND DMG	3 Wnw Hampton	Franklin, IA	Numerous branches and a tree down in the campgrounds.
20:41 UTC	TSTM WND GST 60	Hampton	Franklin, IA	Measured from personal weather station.
20:43 UTC	TSTM WND GST 65	3 Nnw Galt	Wright, IA	Measured from personal weather station.
20:45 UTC	TSTM WND DMG	Galt	Wright, IA	Multiple grain bins heavily damaged. Time estimated via radar.
20:50 UTC	TSTM WND DMG	Ackley	Hardin, IA	Delayed report - emergency manager relayed photos of tree damage via NWSChat. Time estimated via radar.
20:51 UTC	TSTM WND DMG	5 Ne Ackley	Butler, IA	Delayed report. Farm outbuildings damaged. One destroyed. Will assess drone overflight and satellite in the coming days for the possibility of a tornado.
21:11 UTC	TSTM WND DMG	2 Nnw Holland	Grundy, IA	Received report via social media of tree damage around 199th and L Ave near Dike, IA. Time estimated from radar.
21:15 UTC	TSTM WND DMG	Eldora	Hardin, IA	Delayed report - emergency manager sent photos of tree damage in Eldora. Time estimated via radar.
21:39 UTC	HAIL 1.75	4 N Kamrar	Hamilton, IA

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the track Every 2026 tornado in Iowa Every tornado in Iowa since 1950 Warnings in force in Iowa now The forecast where you are

The other tornadoes of July 20, 2026

13 more have been surveyed in the United States that day, so far.

Date	Time	Rating	Where	Path (mi)	Width (yd)
July 20	3:49 PM CDT	EF1	Butler, IA	3.1	25
July 20	3:56 PM CDT	EF1	Butler, IA	4.4	25
July 20	4:00 PM CDT	Unrated	Grundy, IA	2.0	0
July 20	6:31 PM EDT	Unrated	Marquette, MI	2.8	0
July 20	6:47 PM CDT	EF1	Menominee, MI	0.1	35
July 20	6:48 PM CDT	EF0	Wabasha, MN	2.3	20
July 20	7:58 PM EDT	EF1	Delta, MI	0.3	0
July 20	7:03 PM CDT	Unrated	Marathon, WI	2.0	0
July 20	7:11 PM CDT	EF0	Trempealeau, WI	0.9	20
July 20	7:15 PM CDT	EF0	Marathon, WI	8.2	25
July 20	7:47 PM CDT	EF0	Jackson, WI	2.3	50
July 20	7:57 PM CDT	EF0	Menominee, WI	7.8	20
July 20	8:26 PM CDT	Unrated	Shawano, WI	8.8	0

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. A survey can be revised, so the rating, the path and the casualties can all still change.

Sources

NWS Damage Assessment Toolkit, the record the survey teams file from the damage, and NOAA Storm Prediction Center storm reports. Neither is the official database for 2026, which SPC publishes in the spring of 2027.