Thursday is expected to be the warmest, most humid day of a brief heat wave. There was heat and high humidity on Wednesday as the warmest temperature on the day in Marshalltown was 87. Thursday`s high according to the National Weather Service should hit 89. They are predicting a 60% chance of precipitation in the evening time and overnight tonight. But much better weather for the weekend. Around the state on Wednesday Vinton and Mount Pleasant had the high temperatures for the day reaching 89.