Annapurna Circuit Weather: Month-by-Month Guide

When the Circuit Actually Works

The Annapurna Circuit has two peak seasons: October to mid-November (autumn) and mid-March to mid-May (spring). Both windows give reliable Thorong La openings, clear mountain views, and warm-enough nights. The remaining months either bring monsoon rain to the lower half, snow that shuts the pass, or both.

Two climate quirks shape the trek: the Manang side is dry (in the rain shadow behind Annapurna, so even monsoon is drier there than on the southern approach), and Thorong La is a windy col that closes to snow more predictably than the elevation alone would suggest.

Temperatures Across the Circuit

The trek starts in the subtropics and finishes above 5,000 m, so pack for three seasons in one trip. Typical seasonal averages:

Even in October the Thorong La crossing usually starts at 4 am, when the summit is well below -10 °C with a stiff, unrelenting wind. A -15 °C or -20 °C rated sleeping bag is worth it if you have any doubt.

Month-by-Month Breakdown

January and February — Pass usually closed

Cold on the lower trek, and Thorong La is almost always snowed shut from late December through late February. Some trekkers do a one-way lower Circuit as far as Manang, but doing the full loop is not realistic in these months. Lodges above Chame get patchy.

March — Early spring, pass usually opens

Thorong La typically becomes crossable again in mid-to-late March, but early March is still risky. Days on the lower Circuit are pleasant, nights cold at altitude, some snow on the pass approach. Confirm the pass status locally in Manang before committing.

April — Peak spring

The best of spring: rhododendrons blooming through the Marsyangdi valley, warm days, still cold nights at Thorong Phedi. Views become slightly hazier as the month progresses. Lodges are busy but not October-busy.

May — Warm and hazier

Days are warm even at Manang. First half is a good window; the last week sees pre-monsoon storms and afternoon cloud. Thorong La is still fine but views are less crisp than in April.

June, July, August — Monsoon

The lower Circuit (Besisahar to Chame) is wet, leech-infested and prone to landslides on the road, though the Manang and Mustang sections stay much drier. Some hardy trekkers do this window specifically for the Mustang half, but the classic full loop is not the plan in monsoon.

Mid-September to mid-October — Autumn opens

The monsoon retreats and the skies clear. Early autumn can still bring afternoon cloud but nights are pleasant. From late September the trail is reliably in shape.

Mid-October to mid-November — Peak autumn

The single best window of the year. Clear skies, warm-enough days at Manang, cold but survivable nights at Thorong Phedi, and Thorong La reliably open. Book teahouses at Manang, Yak Kharka and Thorong Phedi ahead — they fill up.

Late November and early December — Cold and quiet

Views still sharp, crowds much thinner, but nights bite. Thorong La can close abruptly to a big snowfall — check conditions in Manang. A great window for experienced trekkers who want the trail to themselves.

Thorong La: The Pass That Defines Timing

The 5,416 m Thorong La is the single biggest weather variable on the Circuit. It closes to fresh snow, high wind, or both. Guides at Manang and Thorong Phedi have the current picture and will delay your crossing rather than send you into a whiteout.

• Pass usually open: mid-March to late November.
• Pass usually closed by snow: late December through late February.
• Cross at dawn (3–4 am start) because winds and cloud build through the morning. Aim to be over the pass and dropping toward Muktinath by 11 am.
• 2014 blizzard: on 14 October 2014 a freak Cyclone Hudhud-driven storm dumped 1.8 m of snow and killed dozens of trekkers on the pass. It was a hundred-year event, not a season-defining one, but the lesson is that October is not immune, and you should carry a shelter option and warm gear beyond what you think you need.