Kathmandu Weather in September
Nepal · Subtropical Highlands climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
September in Kathmandu sees average temperatures ranging from a low of 18.7°C (65.7°F) to a high of 26.1°C (79.0°F), with a mean of 21.6°C (70.9°F). Compared to the annual average of 17.7°C (63.9°F), this month is 3.9°C warmer than the yearly norm. Precipitation averages 403.3mm, making it approximately 154.0mm wetter than the monthly average of 249.0mm. The city receives an average of 8.7 hours of sunshine per day during September, with relative humidity averaging 89.3%. Wind speeds reach an average maximum of 7.4 km/h. For travelers, this month offers a temperature experience in Kathmandu, with wetter-than-average conditions compared to the rest of the year.
Kathmandu's subtropical highland climate is shaped by its position in the Kathmandu Valley. I've studied the data and found that the city experiences mild temperatures year-round, with a monsoon season from June to September. The best time for visiting is October to May, when the weather is dry and the Himalayan views are clearest.
September vs Adjacent Months
| Metric | August | September | October |
|---|---|---|---|
| Mean Temp | 22.5°C (72.5°F) | 21.6°C (70.9°F) | 18.9°C (66.0°F) |
| Rainfall | 691.6mm | 403.3mm | 103.4mm |
| Sunshine | 8.1 hrs | 8.7 hrs | 9.7 hrs |
| Humidity | 90.1% | 89.3% | 82.9% |
| Wind | 7.2 km/h | 7.4 km/h | 8.4 km/h |
| Rainy Days | 31.0 | 29.8 | 21.2 |
Seasonal Context
September falls in Autumn in the Northern Hemisphere. Autumn sees temperatures gradually cooling from summer highs. For travelers visiting Kathmandu in September, the data indicates mixed conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Kathmandu in September?
The average temperature in Kathmandu during September ranges from 18.7°C (65.7°F) to 26.1°C (79.0°F), with a mean of 21.6°C (70.9°F).
How much does it rain in Kathmandu in September?
Kathmandu receives an average of 403.3mm of precipitation in September, spread across approximately 29.8 rainy days.
What should I pack for Kathmandu in September?
Based on September weather data, pack layers including light jackets and t-shirts, plus an umbrella. Rain gear is essential — this month averages 403.3mm of precipitation.
Is September a good time to visit Kathmandu?
September is a month with challenging conditions. Plan activities carefully and stay hydrated.
Other Months for Kathmandu
Cities with Similar September Climate (Subtropical Highlands)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 27.72°, 85.32°. Timezone: Asia/Kathmandu. Last updated: 2026-07-30.