Grundy County tornado history

39 tornadoes touched Grundy County, Iowa between 1950 and 2025 — about 0.5 a year. The strongest was rated EF5 (May 25, 2008). Tornadoes here killed 10 and injured 78 people.

39tornadoes since 1950

EF5strongest rating

10killed · 78 injured

41 milongest path · 2008

(E)F0(E)F1(E)F2(E)F3(E)F4(E)F5· dots = start point only

By rating

(E)F012

(E)F115

(E)F26

(E)F31

(E)F41

(E)F51

unrated3

By month

JFMAMJJASOND

Peak month: May.

By decade

’50’60’70’80’90’00’10’20

Strongest tornadoes

Date	Rating	Path	Width	Injured	Killed
May 25, 2008	EF5	41 mi	2,100 yd	70	9
May 30, 1989	F4	11 mi	200 yd	3	0
Apr 16, 1960	F3	29.8 mi	800 yd	5	1
Mar 22, 1991	F2	20 mi	50 yd	0	0
Jul 2, 1999	F2	8.5 mi	50 yd	0	0
May 10, 2001	F2	8 mi	875 yd	0	0
Oct 14, 1966	F2	2.7 mi	100 yd	0	0
Apr 19, 1966	F2	2.3 mi	200 yd	0	0
May 10, 2001	F2	1.7 mi	200 yd	0	0
Jul 2, 1973	F1	30.3 mi	10 yd	0	0
Jun 28, 1990	F1	5.5 mi	30 yd	0	0
Mar 31, 2023	EF1	4.1 mi	80 yd	0	0

Most recent tornadoes

Date	Rating	Path	Width
Aug 18, 2025	unrated	1.4 mi	50 yd
Aug 18, 2025	unrated	0.6 mi	35 yd
Aug 18, 2025	unrated	4.5 mi	50 yd
Mar 31, 2023	EF1	3.5 mi	80 yd
Mar 31, 2023	EF1	4.1 mi	80 yd
Nov 28, 2016	EF0	5.7 mi	50 yd
Nov 28, 2016	EF0	1.5 mi	25 yd
Aug 31, 2014	EF0	1.6 mi	75 yd
Jul 6, 2014	EF1	3.2 mi	100 yd
Jul 6, 2014	EF0	1.5 mi	20 yd
Jun 29, 2014	EF1	1.9 mi	50 yd
Jun 21, 2009	EF0	0.4 mi	30 yd

Deadliest: May 25, 2008, EF5, 9 killed.

Nearby counties

Butler County, IA30 Hardin County, IA47 Black Hawk County, IA40 Tama County, IA47 Marshall County, IA39 Franklin County, IA29 Bremer County, IA29 Story County, IA66

Questions

How many tornadoes has Grundy County, Iowa had?

39 tornadoes touched Grundy County, Iowa between 1950 and 2025 in the NOAA Storm Prediction Center database — about 0.5 per year.

What was the strongest tornado in Grundy County?

The strongest rating recorded was EF5 on May 25, 2008, with a 41-mile path and 9 deaths.

When is tornado season in Grundy County?

Most of its tornadoes happened in May (13 of 39). Tornadoes can occur in any month, so keep alerts on year-round.

Right now: live tornado warnings map · alerts for your location. Dates link to that day’s full storm reports where available (2004 onward).