Rains reached into parts of central and eastern Kansas where drought has been an issue. Did you notice the smell of the rain? It is an odor that has been mentioned many times, including the line from OKLAHOMA: "And the waving wheat can sure smell sweet when the wind comes right behind the rain." As it happens, there is a scientific name for that scent – petrichor. From Greek, the term was first used by Australian scientists Isabel Baer and Richard Thomas in a 1964 Nature article. The article described how oils from certain plants are released during dry conditions. During rain events, the oils are released into the atmosphere together with other compounds to produce the distinctive scent. After a long dry spell, it is certainly a welcome odor!
Mary Knapp, Weather Data Library