Spring (March to mid May) and Autumn (mid Sept to Dec) are the best seasons for the Annapurna Circuit Trekking. The weather is sunny and warm, with outstanding views but the nights are cold and can fall to freezing in higher elevations. Winter (Dec, Jan, Feb) is also good for Annapurna Circuit trek, except the weather and ice and snow which could probably obstruct the pass. The trekking routes are normally very crowded during spring and autumn but during the monsoon and winter the routes are less crowded.