There is one obvious time to come to Okemah: the four days of the Woody Guthrie Folk Festival in mid-July, around Guthrie's birthday on 14 July. The town's population doubles, the Crystal Theatre is packed, and there is music in the streets till the small hours. Outside of WoodyFest, Okemah is very quiet.
Oklahoma summers are hot — daytime highs regularly clear 35 degrees Celsius — so festival-goers come prepared with hats, sunscreen, and water. Spring and autumn are pleasanter but the town has little to offer outside the festival. Winter is cold and grey; skip it unless you are passing through.