Morocco, located between the middle positions of the two permanent discontinuity fronts of the northern hemisphere, is alternately subjected to the influence of one and the other. In winter, the trade winds front is in the Sahara, the polar front in the northern sector of the Mediterranean: the winds from the west and south-west predominate more frequently, the further towards the north; these atmospheric currents, charged with all the humidity acquired in the long maritime journey, encountering the cold lands of northern Africa, which have mountainous barriers, normal to their direction, condense the humidity in the form of significant rains. In summer, the trade winds front is transported to the North. in the northern Sahara at the edge of the Atlas; the polar front follows the same movement; the warming of the soil of northern Africa repels the high pressures towards the NW: the winds no longer head towards the low Mediterranean pressures, but flow towards the center of attraction of the Sahara and therefore the dominant currents are those of the NE. AND. and of the N., more and more prolonged and regular as one advances towards the S. The weakness of the barometric gradient, the predominance of descending and increasingly distant winds; from their point of saturation, they explain the scarcity of rains in this season, the clarity of the sky, the dryness of the atmosphere. but they flow towards the calling center of the Sahara and therefore the dominant currents are those of the NE., E. and of the N., more and more prolonged and regular as one advances towards the S. The weakness of the barometric gradient, the predominance of descending and increasingly distant winds; from their point of saturation, they explain the scarcity of rains in this season, the clarity of the sky, the dryness of the atmosphere. but they flow towards the calling center of the Sahara and therefore the dominant currents are those of the NE., E. and of the N., more and more prolonged and regular as one advances towards the S. The weakness of the barometric gradient, the predominance of descending and increasingly distant winds; from their point of saturation, they explain the scarcity of rains in this season, the clarity of the sky, the dryness of the atmosphere.
The temperature varies greatly according to latitude, altitude, orientation, proximity to the Atlantic or the Mediterranean. The influence of the trade winds and cold waters that bathe the west coast is all the more noticeable the further you advance south: the temperature is more constant in Casablanca than in Tangier, in Mogador than in Casablanca. In Mogador the average of the coldest month (January) is 16 °, 4, that of the hottest month (August) of 22 °, 6; in Rabat the averages are respectively 12 °, 6 and 23 °, 9; in Tangier by 11 °, 7 and 24 °. Moving away from the sea, maritime influences become less sensitive, to yield to the continental ones that prevail; seasonal and daytime excursions are becoming increasingly accentuated towards the interior: summer is very hot in Fez and
Rainfall is of capital importance for Morocco; it is generally a region with little rainfall, but distinctions must be made between one place and another. From the sea towards the Sahara there is a gradual decrease in rainfall, with recrudescences above the high massifs and the most advanced coastal parts of the sea, and a decrease in the plains and in the regions more or less sheltered from maritime influences. The rains are conducted by the winds of the O. and their quantity decreases from N. to S. from Tangier to Mogador and Agadir, as the action of the winds of the O decreases. and increases that of the winds of East. The annual sum of rainfall reaches 829 mm. in Tangier, 494 in Rabat, 391 in Casablanca, 360 in Mogador, 207 in Agadir. The width of the coastal area well watered by the rains narrows towards the S. The average annual rainfall is between 400 and 200 mm. on the Atlantic highlands (Settat, 371 mm.; Mechra Ben Ahbou, 265 mm.; Morocco, 304 mm.); the regions of Meknès and Fez collect the humid currents coming from the OR like a funnel. through the Sebou valleys and its tributaries, which are condensed by the walls of the coastal and Atlantic massifs (Meknès, 555 mm.; Fez, 537 mm.; Taza, 545 mm.). Eastern Morocco, on the other hand, is devoid of rains, starting from Taza, due to the presence of the high chains that shelter it to S. (Oudida, 357 mm.). In the mountainous regions most of the precipitation falls in solid form (above 1000 m. Snow falls from November to May); and the snows, melting at the beginning of summer, feed the rivers and irrigation canals. In the coastal massifs there is a difference between the well watered regions of the O. (Ouezzane, 683 mm.) And the eastern region much drier (Melilla, 335 mm.), Since the western mountains, with their greater heights and the more pronounced advance of the coast to the North., prevent the rains from reaching the region Oriental. The same phenomenon occurs in the Atlas; while the northern side of the Middle Atlas is well watered (el-Hadjeb, 664 mm; Azrou, 803 mm.), the High Atlas, despite the considerable altitude and the proximity of the Atlantic, receives much less rainfall due to the latitude already very southern and due to the influence of the trade winds and the Sahara. However, it is true that snow accumulates there in the cold season, constituting a moisture reserve for the hot season: over 3000 m. the snow mantle lasts about seven months of the year, from November to May inclusive. In the Quaternary period glaciers were formed in the High Atlas at S. di Marocco; In fact, there are glacial cirques that are easily recognizable by their vertical walls and flat bottoms, but currently there are no snowfields or glaciers in the Atlas. Due to the altitude of the mountains that feed the rivers, there are relatively watery regions in Morocco, even if the atmosphere is dry and it rarely rains; such are the oases of Sous, Dra, Tafilelt. In the eastern High Atlas the same phenomenon occurs as in the coastal massif; the further you advance towards the East, the more rainfall becomes scarce and the Saharan character is accentuated. For Morocco 2008, please check payhelpcenter.com.
The rainy season runs from November to May, with two peaks, one at the beginning of the cold season, another at the end, that is, in November and March. The rains generally fall in the form of short and violent downpours; sometimes they fall for a few days to a few hours a day. As in the rest of northern Africa they are very irregular, both in quantity and in terms of the period of the year in which they fall; if they are too late, or if they stop too soon, they can do much harm to agriculture.