For mid April, humidity levels do not get much higher than they were on Monday over most of Iowa. The heat and humidity again helped to fire afternoon thunderstorms with many of them producing severe weather over eastern Iowa. Based on hourly reports, Des Moines topped out at a dew point temperature of 66°F. The featured chart presents the observed max dew point for the year to date period ending 14 April for Des Moines. The 66°F value yesterdays ties for second place behind a 69°F reading back in 1981 (note, that value is somewhat suspect after some review, but alas). Historical archives of dew point temperatures are not really official data nor is the IEM accounting of it, so more caveats to be had with such metrics.