 Now, from your 24-hour weather station, here's Southern Iowa's most accurate forecast on Ottumwa Radio. I'm meteorologist Megan Mulford with a look at your forecast. Mainly clear overnight with a low of 56. East winds 5 to 10 miles an hour. Slight chance of rain showers Monday. High temperatures reach up to 75. Cloudy skies expected. Chance of thunderstorms Monday night, 66. Currently, 63.