The best time to trek the Annapurna Circuit is spring (March to May) and autumn (September to November), when skies are clear, Thorong La at 5,416 m stays open, and daytime trail temperatures sit between 10 and 20 degrees Celsius. Autumn offers the most stable weather of the year, spring adds rhododendron blooms, while winter brings snow risk on the pass and monsoon brings rain to the lower valleys. Each season changes one variable that decides whether the 5,416 m pass is actually crossable: snow load, wind, rain, or crowding.
The Annapurna Circuit is a 160 to 230 km loop around the Annapurna massif in north-central Nepal, dropping from subtropical valleys near 800 m to the high alpine crossing at Thorong La. Elevation swings that wide put weather in charge of the calendar: the trek works well only when the pass is clear of snow and the lower valleys are clear of monsoon rain, and spring and autumn are the two windows when both conditions line up.
Autumn, September to November: the most reliable window
Skies over the Annapurna massif clear fastest in autumn, once the monsoon has washed the dust and haze out of the air and left sharp views of Annapurna and Dhaulagiri. Daytime temperatures in the mid-valley run 15 to 20 degrees Celsius, nights drop below freezing above 4,000 m, and Thorong La stays open with firm, dry footing through the season. October draws the largest number of trekkers on the whole Annapurna Circuit, so lodges and permits are worth booking weeks ahead.
That stability has a price: Manang and Thorong Phedi tea-houses fill fast by mid-October, and latecomers sometimes end up sharing rooms or walking an extra hour to find a bed. Pass-day success rates are highest in this window regardless, so most of our fixed departures cluster here, matching the staged plan in our Annapurna Circuit itinerary.
Spring, March to May: blooms and warming trails
Rhododendron forests between 2,000 and 3,000 m turn the lower trail red and pink through late March and April, spring's signature draw. Daytime temperatures climb steadily from cool in March to warm by May, the pass stays open the whole season, and the longer daylight allows for more relaxed daily stages. Haze tends to build by afternoon, so early starts still capture the sharpest mountain panoramas.
Warm lower valleys come with a trade-off: afternoon cloud builds steadily as May approaches the monsoon, thickest in the final two weeks of the month. April is the sweet spot for trekkers who want the blooms with fewer crowds than October brings, and packing for the wide temperature swing between valley floor and pass is worth planning ahead, a task our Nepal trekking packing list covers in detail.
Winter, December to February: cold, quiet, and snow risk
Trail traffic drops to a trickle in winter, rewarding the prepared with crystal-clear views, though Thorong La at 5,416 m can close for days after a heavy snowfall. Daytime valley temperatures hover near 5 to 10 degrees Celsius while nights at altitude plunge to minus 15 degrees Celsius, and several high tea-houses around Thorong Phedi shut down for the season entirely. Crampons, a guide, and a flexible schedule are non-negotiable for anyone attempting the pass in these months.
Winter's snow risk buys real solitude on the trail, a fair trade for experienced groups who already know how to move on ice at altitude. Many winter visitors shorten the route or switch to a lower option like Poon Hill, while those set on the full pass track the forecast obsessively, the same caution our Thorong La pass crossing guide stresses.
Monsoon, June to August: rain below, rain-shadow above
Daily rain and leeches define the lower Annapurna valleys from June through August, yet the upper circuit beyond Manang sits inside a rain shadow that stays comparatively dry. Manang and the Mustang stretches receive a fraction of the rainfall that soaks the green foothills below, so a monsoon circuit is walkable for trekkers who can tolerate wet lower stages and muddy jeep roads. Landslides occasionally block the road section, a hazard our Annapurna Circuit cost guide factors into transport planning.
Empty trails and the lushest scenery of the year are the upside, and this window doubles as prime season for the rain-shadow trek into Upper Mustang. Late-August departures catch the tail end of the rains just as autumn clarity starts to arrive, bridging straight into peak season.
Thorong La pass conditions by season
Thorong La at 5,416 m is the deciding factor in timing, since the pass alone determines whether the full circuit is walkable in a given month. It stays reliably open through spring and autumn with firm footing and manageable wind, while winter snow can bury the route for days and force a turnaround at Thorong Phedi. Afternoon winds build hard at the pass in every season, and that alone is reason enough to start walking from High Camp well before dawn.
Every month, the crossing itself is the hardest day on the circuit: a pre-dawn departure from High Camp at 4,925 m followed by a long descent to Muktinath at 3,760 m. Snow conditions change that calculation entirely, so winter and early-spring trekkers carry crampons and check the forecast daily, a precaution our Thorong La pass crossing guide details in full. Even peak-season weather is not fully risk-free here: an unexpected pre-winter storm buried the pass on 14 October 2014, killing at least 43 trekkers and guides across the Thorong La, Manang, and Mustang area. Our guides treat any sudden pressure drop or cloud build-up at the pass as an automatic turnaround signal, a standing rule shaped directly by that disaster.
Matching crowds and cost to your dates
Crowds peak in October and April, which raises lodge competition at Manang and Thorong Phedi but also means more fixed departures and easier socialising on the trail. The quietest months are December through February and the monsoon, when tea-houses have space and prices soften, though some high lodges close for winter. Choosing a shoulder window like late September or early May balances good weather against thinner crowds.
Cost shifts with the season, too: peak-month lodges fill fast and transport demand rises, a pattern our Annapurna Circuit cost guide breaks down in numbers. Booking early secures the best rooms for an October departure, while a flexible monsoon or winter trekker finds lower prices and open beds without trying. Departure month shapes both the experience and the budget, so fixing the date is usually the first planning decision once the route itself is settled.
Spring versus autumn: which peak to choose
Autumn and spring are both peak seasons, but they deliver different experiences that suit different trekkers. Autumn from September to November wins on view clarity and weather stability, with the post-monsoon air giving the sharpest panoramas of Annapurna I at 8,091 m and the firmest pass conditions of the year. Spring from March to May wins on colour and warmth, with rhododendron forests in full bloom and longer daylight that eases the stages.
The choice often comes down to crowd tolerance and what you most want to see, since autumn draws the largest numbers while spring spreads trekkers more thinly across the same trail. Photographers and first-time pass-crossers tend to lean toward October for its reliability, while nature lovers and anyone wanting warmer nights pick April instead. Both peaks deliver a high success rate on Thorong La, so both anchor our fixed-departure calendar, and packing correctly for the chosen window still matters, as the Nepal trekking packing list sets out.
How weather shapes the daily stages
Daily weather on the circuit follows a predictable rhythm in the peak seasons: clear mornings, building cloud by early afternoon, and cold, clear nights. Guides use that rhythm deliberately, starting soon after dawn so the group reaches each day's destination before afternoon cloud rolls in and swallows the mountain views. The lower valleys near Besisahar feel subtropical and warm, while the upper sections past Manang at 3,540 m turn alpine and cold within a single day's climb.
Understanding this altitude-driven shift lets you plan layers and timing for each stage rather than for the trek as a whole. A warm 20-degree morning at Chame can become a sub-zero evening at Thorong Phedi, so the same day demands both a sun hat and a down jacket. Reading the weather alongside the staged altitude gain is the practical skill that makes a peak-season circuit comfortable, and the full day count sits in our Annapurna Circuit itinerary.
Month-by-month temperature and conditions
| Month | Valley day temp | Pass condition | Crowds |
|---|---|---|---|
| March | 10–15°C | Open, some snow | Moderate |
| April | 15–18°C | Open | Busy |
| May | 18–22°C | Open, hazy | Moderate |
| Jun–Aug | 20–25°C | Open, wet below | Quiet |
| September | 15–20°C | Open | Building |
| October | 12–18°C | Open, dry | Peak |
| November | 8–15°C | Open, cold nights | Busy |
| Dec–Feb | 5–10°C | May close, snow | Very quiet |
October and April top most trekkers' plans for a reason: the table shows both months pairing stable pass conditions with manageable temperatures, a combination no other window matches as closely. Shoulder weeks just before or after those two months are the practical compromise for trekkers chasing thinner crowds without gambling on winter snow or monsoon rain.
Pick your month with Annapurna Trekking
Annapurna Trekking runs fixed departures across the spring and autumn peaks and tailors private dates for winter and monsoon trekkers who want the quiet trail. Our TAAN-certified guides track the Thorong La forecast and keep groups to a maximum of twelve so we can adapt the schedule to the weather. To choose the best month for your Annapurna Circuit and lock in a departure, message our team on WhatsApp at +977 984 159 5962 or use our contact page.
