March to May and October–November are the best months: warm enough for the desert sites around Madaba but not blistering. Spring is especially attractive — the high plateau around the city briefly turns green, and the wild flowers in the gorges are spectacular.
Summer (June–September) is hot but dry, with daytime temperatures often above 35°C. Mount Nebo can be unpleasant in the middle of the day; aim for an early start. Winter (December–February) is cool to cold, with occasional snow on the higher ground, but the churches and Archaeological Park stay open. Christmas in Madaba is genuinely festive — the town has been a major Christian centre for 1500 years and the streets fill with carols and processions on Christmas Eve.