Central Oklahoma swings between hot, sticky summers (highs above 33°C / 92°F from June to August) and short, sharp winters with the odd ice storm. Spring and autumn are the comfortable seasons, with the bonus that storm season in April–May can produce dramatic skies — and, occasionally, tornadoes; check a NOAA radar app if dark clouds build in the afternoon.
Time a visit to Sorghum Day in late September, a one-day festival celebrating the sweet syrup once boiled down on local farms. There's a parade, a fiddle competition, vendors and a sorghum-tasting tent. It's small and unselfconscious — a real small-town American festival.