The city receives 238.5 millimetres of precipitation a year, a semi-arid figure, and sits at around 800 metres on a plateau. Those two facts together produce an unusual calendar for the region: dry, bearable summers and winters considerably more uncomfortable than almost anyone expects.
01 Zero millimetres
The distribution is clear-cut. From November to March, 216.4 of the annual 238.5 millimetres fall, with January leading (60.6 mm over eleven days) and February just behind (57.9 over almost eleven). From April to October, by contrast, the seven months together do not reach 17 millimetres.
02 Winter surprises people
Here is the mistake most people make. This part of the world is associated with desert and winter is assumed to be mild, and it is not: January has an average high of 12.6 degrees and a low of 4.2, and the absolute record is −4.5. At 800 metres on an open plateau, the cold is real.
And there is a practical consequence worth anticipating: at that altitude, with those lows, snow is possible. It is not frequent, but when it falls it paralyses a city built on steep gradients, which means closed roads and impossible journeys for a day or two. December and January are the months at risk.
July: 0.0 millimetres of rain and 387 hours of sun. January: 60.6 millimetres, eleven rainy days and a record of −4.5 degrees.
03 A thousand metres further down
And now the part no climate table for the capital records. A little over half an hour by car to the west, the ground collapses: the city sits at around 800 metres above sea level and the Dead Sea shore lies some 400 below. That is more than 1,200 metres of drop over a very short distance.
The effect on temperature is precisely what you would expect: it is considerably hotter down there than up here, all year and at any hour. In practice that turns a disadvantage into a tool. In winter, when the city is at 12 degrees and raining, the valley is the plan; in mid-August, at 32.8 up top, the valley is exactly what to avoid.
04 Two windows, not one
The calendar has two good seasons, symmetrical around summer. The spring one is April and May: highs of 23.6 and 28.1 degrees, 8.2 and 3.0 millimetres of rain, and 267 and 329 hours of sun. The autumn one is September and October: highs of 30.9 and 27.2, with 0.1 and 5.4 millimetres.
Between the two there is a difference that settles many trips: spring brings green to the plateau after the winter rains, and autumn brings the brown landscape of late summer. If the trip includes going out into the country, April and May win; if it is a city-and-ruins trip, September and October are just as good and usually cheaper.
05 The verdict
April, by a clear margin. It combines a high of 23.6 degrees and a low of 11.2 — the perfect range for walking all day in a city of slopes — only 8.2 millimetres of rain and 267 hours of sun, and it arrives just as the plateau still holds its winter green. October is the second option and not far behind.
And a rule that saves grief: do not write summer off for the heat. At a high of 32.8 degrees, humidity of 44 to 51 % and no rain, the plateau in August is perfectly bearable if you start the day early. What you should avoid in summer is going down into the valley, where the same day is something else entirely.
