Het weer in Isfahan (Esfahan) in september

Forum posters consistently rate October among Iran's best travel windows weather-wise, alongside late March through May, describing conditions as still very nice - not cold, and not the intense heat of summer even in the country's warmer southern regions. Posters specifically flag October's added logistical benefit: school holidays have just ended, meaning noticeably fewer domestic crowds at popular sites than during the summer or early-autumn peak. Posters note Isfahan itself can turn a bit chilly at certain points in the season, though overall the balance stays comfortable. Posters generally rate October as one of the best, most balanced months to visit Isfahan, pairing pleasant temperatures with lighter crowds.

Early April to the end of May is the window the Iran forum agrees on, and April is high season for good reason: Isfahan runs near 24°C by day, rain down to about three days, and humidity the forum puts in the 30s. The nights are the surprise — an average low near 9°C, so a sweatshirt earns its place even in a warm, dry month. Regulars add a timing note that has nothing to do with weather: late March is Nowruz, when Iranians travel domestically and sites fill up, so April is both warmer and calmer than the fortnight before it.