Het weer in Petra (Wadi Musa) in september

Regulars describe this as transitional - early in the month still unbearably hot for children or older visitors, while the back half brings falling temperatures and a genuinely comfortable window for hiking, neither too hot nor too cold. Our row backs the dry heat, 31.1C reading as a real 31C, over 19.6C nights, with rain essentially absent, 0.2mm and effectively zero rainy days, and humidity down to 46 percent. Regulars are consistent on one practical tip regardless of exactly which week a visit falls in: the site opens at 6am, and arriving early is the standard way to see the most before the day's heat builds. Dry desert heat rather than the humid version found in Aqaba is what regulars say makes even the hot stretch more bearable than the number alone suggests. The record: 11.2 hours of sun, a 15.4 kph wind and AQI 55.

March and October are the two months regulars name as Jordan's best, and March comes with a catch in both directions. The wildflowers run from now to May, which is why the country fills and hotel and camp prices climb. And it is still inside the wet half of the year: our 19.5mm across 3.1 days is nothing in itself, but rain upstream can close this site for the day, which is the risk to check rather than the forecast. Days reach 18.9C and feel like 16C; nights fall to 8.1C and feel like 5C, a ten-degree drop on very dry air - 50 percent humidity, a dew point of 1.2C. Layers rather than a coat. The record: 10.7 hours of sun, a 17.4 kph wind and AQI 52.

Regulars call early November one of the best weeks of the Jordanian year and then add the altitude: this site sits high, so mornings and shaded rock stay cold long after the sun is up, and the night wants a jacket rather than a jumper. Our row gives 20.5C by day reading as 18C and 11C at night reading as 9C, at 53 percent humidity with a dew point of 4.6C. Rain is almost nothing, 5.8mm across 1.4 days - but the one thing to check before walking is whether any has fallen upstream, because this is a canyon and flash flooding has closed the site in wet years. Sightseeing starts early and finishes in daylight at 10.6 hours. The record: 9.4 hours of sun and AQI 50.

May at Petra is before the worst of the heat and already hot enough to organise the day around. The standing advice is to be at the entrance around six, seven at the latest: you miss the midday sun, you get the site with fewer people in it, and you have time for the walk out. There is very little shade anywhere inside. What regulars recommend wearing is counter-intuitive - cotton, long sleeves and long trousers, to keep the sun off arms and legs - plus a hat, sunscreen and more water than you think you need. The Monastery climb takes an hour to an hour and a half. The record: 28.4C days that feel like 27C, 15.9C nights, humidity 34 percent, 1.2 precipitation days and 12.6 hours of sun.

Petra forum threads describe December and January as the coldest months here, with typical daytime highs around 10-15C dropping to near freezing overnight - real winter given Petra's elevation, with the occasional snow event, though posters called it roughly a once-a-year occurrence that can disrupt plans for a few days when it happens. Conditions swing meaningfully day to day too, from sunny and mild one day to cold and windy the next, and real rain is a genuine possibility. Visitors who entered before dawn to catch sunrise consistently described needing hats, gloves and layered jackets early on, then stripping down to a single long-sleeve shirt once the sun climbed and the hiking warmed them up.