Spring (March to May) and autumn (September to early November) are by far the best months. The almond blossom peaks in February in the lower gorge; the rose harvest in the nearby Vallée des Roses runs through May; the dates ripen in September and October. Temperatures are mild — daytime highs in the mid-20s, cool nights — and the river runs full enough to be photogenic.
Summer (June to August) is hot, with daytime temperatures over 35°C and very little shade in the upper gorge. Winter brings sharp nighttime cold (down to freezing), short days, and possible snow on the passes north of Msemrir, though the lower valley itself remains driveable.
The annual Festival of Roses in Kelaa M'gouna, 30 km west, runs over one weekend in early May with parades, music, and rose-water tastings — worth timing a visit around.