Tornado History Map

Delaware County, Iowa tornado history

48 tornadoes recorded in or across Delaware County from 1954 to 2025, coloured by rating on the map.

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Years1950 to 2025
Rating (F or EF scale)

Shows tornadoes that started in, or crossed, the chosen state. To see how many have passed near you, search a town or ZIP code, or tap the map.

Key
  • F0 / EF0 Light damage
  • F1 / EF1 Moderate damage
  • F2 / EF2 Considerable damage
  • F3 / EF3 Severe damage
  • F4 / EF4 Devastating damage
  • F5 / EF5 Incredible damage
  • Unknown Not rated (2007 onwards)

How to read the lines. Each line is one tornado, drawn from where it started to where it ended, coloured and sized by its rating. A dot means the record has no end point. Tap a line for its details, or tap anywhere else to see how many tornadoes have passed nearby. Weaker tornadoes appear as you zoom in. Ratings use the Fujita (F) scale before 1 February 2007 and the Enhanced Fujita (EF) scale from then on.

Tornadoes in Delaware County

The Storm Prediction Center records 48 tornadoes whose paths touched Delaware County, Iowa between 1954 and 2025. None of them is recorded as having killed anyone. The busiest month is May, with 10 tornadoes. The strongest was an F4 on 30 April 1954. The most recent was on 11 July 2025.

  • 48tornadoes
  • 0deaths
  • 26injuries
  • 831per 10,000 sq mi of land

A tornado that crossed several counties counts in each one, so county counts add up to more than the state's.

How strong were the tornadoes in Delaware County?

RatingTornadoesShare
F0 / EF01225%
F1 / EF11735%
F2 / EF21021%
F3 / EF348%
F4 / EF436%
F5 / EF500%
Unknown rating24%

Delaware County tornadoes over time

Tornadoes by decade
Bar chart of tornadoes by period. The most is 9 in 1990s.1950s31960s41970s41980s61990s92000s82010s82020s6

The 2020s only run to 2025, so that bar is for a shorter period. The record starts in 1950.

Show the numbers
PeriodCount
1950s3
1960s4
1970s4
1980s6
1990s9
2000s8
2010s8
2020s6
Tornadoes by month
Bar chart of tornadoes by period. The most is 10 in May.Jan0Feb0Mar6Apr5May10Jun10Jul9Aug5Sep1Oct0Nov2Dec0
Show the numbers
PeriodCount
Jan0
Feb0
Mar6
Apr5
May10
Jun10
Jul9
Aug5
Sep1
Oct0
Nov2
Dec0

Records for Delaware County

Notable tornadoes in Delaware County

Many of these tornadoes killed or injured people. The numbers are the official record's, and they may be revised.

More in Iowa

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