We will lose another hour and 13 minutes of daylight in October which will lead to much cooler temperatures by the end of the month. The 30 year average high starts at 72, cooling to 62 by the 31st. Average low temperatures fall to near 40 by the end of the month.
The jet stream usually drops farther south more consistently as we head through October sending storm systems and rain through Missouri more frequently. Looking at 30 years of data, the average rainfall comes in at 3.31″ for the month. However, in 1952 we only got .16″ rain which is the driest October on record. The wettest October occurred in 1941 with 13.44″ rainfall.
The growing season usually comes to an end by the end of October with the average date of the first freeze around October 25th. There is a 50% chance of a freeze before October 16th and a 90% chance by November 1st.