Here is a summary of record highs as reported by the NWS


Waterloo          86    85(1931)
Moline, IL        86    83(1941)
Cedar Rapids      86    84(1931)
Spencer           88    84(1931)
Lamoni            87    80(1941)
Mason City        85    83(1931)
Ottumwa           87    86(1908)
Atlantic          88    86(1908)
Sioux City [1]    91    87(2003)
Des Moines        89    89(1883) TIED
St Joseph, MO     92    88(1936)
Rochester, MN     82    80(1941)
Mankato, MN       84    84(1985) TIED
Minneapolis, MN   84    78(1976)

[1]  This was the fourth earliest date in the year for the 
     first 90 degree reading.  The earliest date was 
     30 March 1968 for Sioux City.