Primary Trekking Seasons in Nepal

Autumn (September to November)

  • Considered the best trekking season overall
  • Stable weather with clear skies
  • Daytime temperatures: 15-20 degree celsius at 3,000m
  • Night temperatures: 0-10 degree celsius at 3,000m
  • Excellent mountain visibility
  • Trails in good condition after monsoon
  • Popular trails can be crowded

Spring (March to May)

  • Second best trekking season
  • Pleasant temperatures and blooming rhododendrons
  • Daytime temperatures: 15-25 degree celsius at 3,000m
  • Night temperatures: 0-10 degree celsius at 3,000m
  • Some pre-monsoon haze may develop in May
  • Fewer crowds than autumn

Other Trekking Periods

Winter (December to February)

  • Cold but possible for lower altitude treks
  • Daytime temperatures: 10-15 degree celsius at 3,000m
  • Night temperatures: -10 to 0 degree celsius at 3,000m
  • Clear skies but very cold at high elevations
  • Some high passes may be snowed in
  • Few tourists and discounted rates

Monsoon (June to August)

  • Generally not recommended for most treks
  • Heavy rainfall and leeches on trails
  • Clouds obscure mountain views
  • Landslide risk on some routes
  • Rain-shadow areas like Upper Mustang remain dry

Best Months for Popular Treks

Trek Best Months Alternative Months Months to Avoid
Everest Base Camp Oct-Nov, Mar-Apr Sep, Dec, Feb Jun-Aug
Annapurna Circuit Oct-Nov, Mar-Apr Sep, Dec Jun-Aug, Jan-Feb (pass)
Langtang Valley Oct-Nov, Mar-Apr Sep, Dec Jun-Aug
Upper Mustang May-Oct Apr, Nov Dec-Mar (cold)

Monthly Weather Conditions

Month Avg Temp (3,000m) Rainfall Trekking Conditions
September 15 degree celsius day / 5 degree celsius night Decreasing Improving after monsoon
October 18 degree celsius day / 2 degree celsius night Low Excellent
November 15 degree celsius day / -3 degree celsius night Very low Excellent, colder nights
March 16 degree celsius day / 3 degree celsius night Moderate Good, warming up
April 20 degree celsius day / 5 degree celsius night Moderate Excellent
May 22 degree celsius day / 8 degree celsius night Increasing Good, some pre-monsoon haze

Special Considerations

Altitude Factors

  • Higher altitudes (above 4,000m) have shorter optimal seasons
  • Passes like Thorong La are usually only open March-November
  • Winter brings extreme cold at high elevations

Festival Impacts

  • October festivals (Dashain, Tihar) may affect availability
  • Teahouses may be closed or full during major holidays
  • Local services reduced during festival periods

Recommended Preparation

  • Book popular treks 2-3 months in advance for peak seasons
  • Check current weather forecasts before departure
  • Pack appropriate gear for expected temperatures
  • Be flexible with itineraries in shoulder seasons