Nepal Kathmandu Weather in September — Climate Guide
September in Kathmandu is moderate
September is moderate for Kathmandu.
September is the transition out of the monsoon, which usually retreats by late month — warm days near 28°C, mild nights around 19°C, and steadily decreasing rain (about 200mm). Early September is still wet; the back half clears noticeably.
The air stays clean from the rains, and as skies clear late in the month the mountains begin to reappear, making the last week or two a promising lead-in to the autumn peak season. Crowds and prices start to build accordingly.
Travel score
Kathmandu September Weather Stats
Avg High
28°C
Avg Low
19°C
Rainy Days
13
200mm total
Sunshine
5.5h
Daily avg
Humidity
78%
muggy
UV Index
7
High
Wind
6 km/h
Gusts 15
Crowds
Moderate
At attractions
September Sunrise & Sunset
Air Quality
PM2.5
26 μg/m³
PM10
55 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
30°C
Nighttime
19°C
Humidity and wind affect how the actual temperature feels.
Wind
6 km/h
Max gust 15 km/h
Activities Recommended for September
September Travel Pros & Cons
Pros
- Indra Jatra in Kathmandu Durbar Square
- Clean post-monsoon air
- Mountains reappear late in the month
- Lush green valley
Cons
- Early-September rain still heavy
- Mountains hazy until late month
- Crowds and prices building
- Lingering humidity
September Events & Festivals
- Monsoon retreats (usually late September)
- Indra Jatra (Sep) — masked dances & Kumari chariot in Kathmandu Durbar Square
- Air still clean post-monsoon
- Crowds building toward the autumn peak
Kathmandu in September — Full Picture
September is the transition out of the monsoon, which usually retreats by late month — warm days near 28°C, mild nights around 19°C, and steadily decreasing rain (about 200mm). Early September is still wet; the back half clears noticeably.
The air stays clean from the rains, and as skies clear late in the month the mountains begin to reappear, making the last week or two a promising lead-in to the autumn peak season. Crowds and prices start to build accordingly.
The cultural highlight is Indra Jatra, one of Kathmandu's great festivals, centered on Kathmandu Durbar Square — masked dances, the chariot procession of the living goddess Kumari, and days of celebration. It's a superb time to be in the old city.
Pack for the tail of the monsoon: light clothes, an umbrella for lingering afternoon showers, and a light evening layer. Late September onward is when the year's best stretch for clear skies, mountain views, and trekking begins.
What to Wear & What to Pack
Monsoon winding down (retreats by late month). Warm days around 28°C, mild nights near 19°C, decreasing rain. Light clothing, an umbrella for lingering showers, and a light layer for evenings. Air still clean; mountains start to reappear late in the month.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
27.3°C
12°C
7.7/mo
Summer (Jun·Jul·Aug)
28°C
19.7°C
18.3/mo
Autumn (Sep·Oct·Nov)
Current25.7°C
13.7°C
6.3/mo
Winter (Dec·Jan·Feb)
20°C
3°C
2/mo
Kathmandu Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| 19° | 2° | 2d·15mm | 7h | 70% | 5 | Moderate | Shoulder | |
| 21° | 4° | 3d·20mm | 7.5h | 65% | 6 | Moderate | Shoulder | |
| March (Best) | 25° | 8° | 4d·35mm | 8h | 60% | 8 | Busy | Peak |
| April (Best) | 28° | 12° | 7d·60mm | 8h | 60% | 9 | Very busy | Peak |
| 29° | 16° | 12d·120mm | 7h | 68% | 10 | Moderate | Shoulder | |
| 28° | 19° | 16d·240mm | 5h | 78% | 9 | Quiet | Low season | |
| 28° | 20° | 20d·365mm | 4h | 82% | 8 | Quiet | Low season | |
| 28° | 20° | 19d·330mm | 4.5h | 82% | 8 | Quiet | Low season | |
| 28° | 19° | 13d·200mm | 5.5h | 78% | 7 | Moderate | Shoulder | |
| October (Best) | 26° | 14° | 5d·50mm | 8h | 68% | 6 | Very busy | Peak |
| November (Best) | 23° | 8° | 1d·10mm | 7.5h | 65% | 5 | Very busy | Peak |
| 20° | 3° | 1d·10mm | 7h | 68% | 4 | Moderate | Shoulder |
View Other Months
Kathmandu September Hotel Picks
Frequently Asked Questions
Is September a good time to visit Kathmandu?
Kathmandu in September is moderate. Tourist crowds are moderate and flight/hotel prices are shoulder.
What's the average temperature in Kathmandu in September?
Kathmandu September averages a high of 28°C and a low of 19°C.
Does it rain much in Kathmandu in September?
Kathmandu September averages 200mm of rainfall over about 13 rainy days.
What should I wear in Kathmandu in September?
Monsoon winding down (retreats by late month). Warm days around 28°C, mild nights near 19°C, decreasing rain. Light clothing, an umbrella for lingering showers, and a light layer for evenings. Air still clean; mountains start to reappear late in the month.
What time are sunrise and sunset in Kathmandu in September?
Kathmandu September sunrise is 05:35 and sunset is 18:05, with 12h 30min of daylight.
What's the air quality like in Kathmandu in September?
Kathmandu September air quality (AQI) averages 50, rated Good. PM2.5 averages 26μg/m³.
What activities are recommended in Kathmandu in September?
In September, Kathmandu is great for Indra Jatra festival (Kumari chariot), Durbar Squares + stupas, Late-month clear-sky mountain flights.
Is September peak season in Kathmandu?
Kathmandu September crowds are moderate and prices are shoulder. You can travel relatively comfortably without long queues.
Best Months to Visit Kathmandu
View Other Months
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.