Summer in Kathmandu means warm temperatures, heavy rainfall, and those long daylight hours that really shape daily life. You’ll find average highs hovering around 28°C (82°F), and nights stay mild, so the warmth feels pretty steady. But honestly, it’s the monsoon that stands out most, bringing frequent, sometimes intense downpours that turn the valley lush and green.
The rain tends to define summer weather in Kathmandu, but it also keeps the air feeling fresh and the scenery looking vibrant. Humidity climbs during this time, and you’ll see fewer sunny hours under those cloudy skies. Still, when the rain lets up, you get these amazing mountain views and much more comfortable conditions for exploring.
If you want to make the most of these months, it helps to understand how temperature, rainfall, and humidity work together. Whether you’re packing, planning outdoor adventures, or just trying to figure out what to expect, knowing Kathmandu’s summer climate definitely smooths out the experience.
Overview of Kathmandu Climate
Kathmandu’s climate owes a lot to its valley location, its elevation, and its subtropical setting. You’ll go through warm summers with heavy rainfall, mild autumns, cool winters, and a clear wet-dry rhythm that shapes the year.
Geographical Location and Elevation
Kathmandu sits in central Nepal, right in the Kathmandu Valley, surrounded by hills that soar over 2,000 meters. The city itself sits at about 1,337 meters (4,386 feet) above sea level, so temperatures stay more moderate than in Nepal’s lowlands.
Because the valley is shaped like a bowl, air circulation doesn’t always work in your favor. Sometimes, humidity and haze get trapped, especially when it’s raining a lot. Nights feel noticeably cooler compared to daytime, and that’s thanks to the altitude.
The mountains around the valley also play a big role in rainfall. Moist air from the south gets pushed up, which leads to those heavy monsoon showers in summer. This unique geography is a big reason Kathmandu’s seasons feel so distinct.
Köppen Climate Classification
Kathmandu falls under the Cwa Köppen climate classification, so that’s a humid subtropical climate with dry winters. You get warm, wet summers and cooler, drier winters.
From May to September, most of the year’s rain falls. July usually takes the crown for wettest month, with more than 360 mm of rain on average. December and January? Much drier, often below 15 mm.
Temperatures follow a pretty clear pattern. Summer highs often hit 28–29°C (82–84°F), while winter lows can dip to 2–4°C (36–39°F) at night. So, Kathmandu stays cooler than much of South Asia, but it’s still warm enough for subtropical plants.
Annual Weather Patterns
The year divides into four seasons.
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Spring (March–May): Mild to warm, some rain, days get longer.
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Summer/Monsoon (June–August): Heavy rain, high humidity, warm temperatures.
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Autumn (September–November): Clear skies, nice temperatures, not much rain.
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Winter (December–February): Cool days, cold nights, barely any rainfall.
Sunshine hours really swing throughout the year. In July, you might get 4–5 hours per day, but in February, it jumps to 9–10 hours. Humidity also shifts a lot—summer is sticky, winter feels much drier.
Average Summer Temperatures in Kathmandu
Summer in Kathmandu means warm days, mild nights, and humidity that just keeps rising. The temperature range stays pretty tight, but things like cloud cover and rainfall make early and late summer feel a bit different.
Monthly Daytime and Nighttime Averages
From June through August, daytime highs usually sit between 77°F and 89°F (25°C–32°C). Mid-June is the warmest, with average highs at about 84°F (29°C).
Nights stay comfortable, averaging 62°F to 71°F (17°C–22°C). July nights are usually the warmest, with lows around 69°F (20°C). This combo of warm days and mild nights makes Kathmandu’s climate feel more moderate than Nepal’s hotter lowlands.
Here’s a quick look at the averages:
| Month | Avg High | Avg Low |
|---|---|---|
| June | 83–84°F (28–29°C) | 67°F (19°C) |
| July | 82–83°F (28°C) | 69°F (20°C) |
| August | 81–82°F (27–28°C) | 68°F (20°C) |
Temperature Extremes and Variability
You won’t see wild temperature swings in Kathmandu’s summer. Highs above 89°F (32°C) are rare, and lows below 62°F (17°C) don’t really happen. The city’s valley location and elevation of about 4,250 feet (1,300 m) keep things stable.
The hottest day usually lands in mid-June, and the coolest summer nights show up at the season’s start. By late August, more clouds and rain pull daytime highs down a bit.
Unlike tropical climates where temperatures can jump around each day, Kathmandu’s summer changes are gradual, mostly because of the monsoon and humidity. So, the weather stays pretty predictable.
Comparison With Other Seasons
If you stack summer against winter in Kathmandu, it’s a big contrast. January highs average about 64°F (18°C), and nights can drop to 37°F (3°C). That’s almost a 30-degree difference from the warmest summer days.
Spring and autumn bring more sun and less humidity, with highs between 70°F and 80°F (21°C–27°C). These “in-between” seasons feel drier and more comfortable, especially if you’re not a fan of muggy summer weather.
Summer is the warmest, but it’s also wetter and cloudier because of the monsoon. If you want clearer skies, late spring or early autumn might suit you better than the middle of summer.
Summer Rainfall and Monsoon Impact
Most of Kathmandu’s yearly rain falls during summer, and heavy rains really shape how people get around and plan their days. The monsoon brings frequent downpours, high humidity, and not much sunshine.
Monthly Rainfall Totals
Rainfall jumps sharply from June through August. June usually sees about 230–240 mm, and July peaks around 360 mm. August keeps things wet, often topping 300 mm.
Winter months barely get 15 mm, so the difference is huge. Nearly 80% of Kathmandu’s annual rain falls during this short summer stretch. That much rain impacts agriculture, water supply, and pretty much anything outdoors.
| Month | Average Rainfall (mm) |
|---|---|
| June | ~236 mm |
| July | ~363 mm |
| August | ~331 mm |
Summer is by far the wettest time of year.
Number of Rainy Days
Rainy days pile up too. In July, expect 23 to 29 days with measurable rain. June and August aren’t far behind, usually seeing 20 to 25 rainy days each.
December, on the other hand, averages fewer than 5 rainy days. The weather in Kathmandu really flips between the dry and wet seasons.
Most rain falls in the late afternoon or evening, but overnight storms happen too. You’ll get some sunny breaks, but clouds usually win out in summer. This can make mountain views rare and might mess with outdoor sightseeing.
Monsoon Season Characteristics
The summer monsoon shapes Kathmandu’s climate more than anything else. Moist air from the Bay of Bengal moves north, dumping heavy rain as it hits the valley.
Humidity often climbs above 75%, and daytime temps hover around 28–29°C. The muggy air can feel pretty oppressive if you’re out and about for long.
But the monsoon isn’t all bad. Farmers depend on it to grow rice and other crops. Reservoirs and groundwater refill during these months, making sure there’s enough water when it dries up later.
Still, heavy downpours can cause flooding, landslides, and travel delays. Roads might get muddy or blocked, and flights can face disruptions. If you’re coming during this season, pack rain gear and expect plans to change.
Humidity and Sunshine During Summer
Kathmandu’s summer means high humidity and lots of cloud cover, thanks to the monsoon. Rain peaks in July, and the mix of moisture and limited sunshine really shapes what it’s like to be in the city.
Average Humidity Levels
Once the monsoon starts in June, humidity shoots up. Average relative humidity ranges from about 70% to over 80% during the summer. July and August are usually the stickiest, with high humidity day and night.
This much moisture makes the air feel heavy, especially when highs sit near 28°C to 29°C (82°F to 84°F). Evenings don’t offer much of a break, since humidity stays high after dark.
For comfort, lightweight clothes that dry fast and breathe well are a lifesaver. If you’re planning outdoor stuff, keep in mind that things dry slowly and gear might stay damp for a while.
| Month | Avg. Humidity | Conditions |
|---|---|---|
| June | ~70% | Humidity rising, monsoon starts |
| July | ~80%+ | Peak humidity, lots of rain |
| August | ~80%+ | Still humid, starts to ease up later |
Sunshine Hours and Cloud Cover
Daylight stretches over 13 hours in early summer, but don’t expect lots of sun. In July, you might only get 4–5 hours of direct sun per day, while winter can bring over 9 hours.
Clouds move in fast from June—by July and August, skies are overcast more than 70% of the time. This blocks mountain views and can change your sightseeing plans.
Even if there’s less sunshine, the long days mean you still have plenty of time for travel. Just be ready for rain showers and cloudy weather to interrupt outdoor plans. Bringing rain gear and having backup indoor activities is a smart move.
Wind, Air Pressure, and Additional Weather Factors
During Kathmandu’s summer, the monsoon season really takes over the atmosphere. Wind, pressure, and visibility all shift with the heavy rain, high humidity, and cloud cover, and that affects both comfort and travel.
Typical Wind Patterns
Winds in Kathmandu during summer usually stay light to moderate, averaging 5–15 km/h. They mostly blow in from the south and southeast, bringing moist air from the Bay of Bengal. That’s what drives the monsoon across the valley.
You might notice breezes picking up in the afternoon when the heat builds and convection gets going. These winds can bring some relief from the humidity, but they also pull in thick clouds that block the sun.
Kathmandu doesn’t get strong gales or cyclones like coastal areas do. The hills around the valley slow things down, so the air often feels heavy and still—especially before a rainstorm.
Air Pressure Changes
Air pressure in Kathmandu usually stays pretty steady compared to lowland tropical places, but you’ll notice it drop when the monsoon gets going. In summer, pressure averages around 1000–1010 hPa, just a bit lower than what you get in winter.
You might sense this shift as storms roll in. When the pressure drops, rain showers or thunderstorms often follow—especially in July and August. The valley’s shape can make this more intense since it traps moisture and keeps the clouds hanging around.
Kathmandu sits at about 1,400 meters (4,600 feet) above sea level, so its baseline pressure is naturally lower than at sea level. Most people don’t find this extreme, but if you’re sensitive to pressure changes, you might feel a little tired or get a headache when the weather turns stormy.
Visibility and Air Quality
During summer, visibility in Kathmandu often drops because of heavy rain, mist, and cloud cover. On rainy mornings, fog can hang in the valley, and you might only see a few kilometers ahead.
But here’s the upside—air quality usually gets better than in winter. Rain washes away dust and pollution, leaving the air fresher. Breathing feels easier, though the humidity can still weigh you down.
Catching clear views of the Himalayas in July and August doesn’t happen often. If the sky does clear after a rain, you might get a quick, stunning look at the mountains. For most city days though, expect hazy skies and not much sunshine.
Travel Tips for Visiting Kathmandu in Summer
Summer in Kathmandu means warm days, frequent rain, and sticky humidity. You’ll need to work around the monsoon, pack smart, and pick activities that suit the weather. A bit of planning goes a long way for a comfortable trip.
Best Months to Visit
Summer runs from June to August in Kathmandu. Daytime highs usually hit 26–28°C (79–82°F), while nights cool down to about 18–19°C (64–66°F).
July brings the heaviest rain, with over 500 mm of precipitation and showers almost every day. June and August aren’t as wet, but you’ll still get plenty of rain.
If you want to dodge the worst downpours, try early June or late August. Those times give you warm weather with a little less rain, though skies stay mostly cloudy.
You’ll notice fewer crowds in summer than in spring or autumn, so hotels are cheaper and attractions feel quieter. Just keep in mind—hiking trails near the city can get muddy and pretty slippery after rain.
What to Pack for Summer Weather
You’ll want to be ready for both heat and rain. Go for lightweight, breathable clothes on warm days. A quick-dry shirt, comfortable pants, and sandals or walking shoes work well for getting around the city.
Since the monsoon is in full swing, waterproof gear is a must. Bring a compact rain jacket, umbrella, and a water-resistant backpack cover. Streets can get muddy, so sturdy shoes that can handle wet ground will definitely help.
Humidity runs high, so pack extra sets of clothes to stay dry. Don’t forget a hat, sunscreen, and insect repellent—sunny breaks and mosquitoes often pop up.
If you’re planning to visit temples or cultural spots, bring clothes that cover your shoulders and knees. It’s more comfortable and shows respect for local customs.
Weather-Related Activities and Events
Heavy rain can put a damper on long treks, but honestly, Kathmandu still offers plenty to do in summer. You might wander through indoor spots like Durbar Square museums, poke around art galleries, or visit religious sites such as Swayambhunath Stupa.
If you’re itching to get outside, you can try short day hikes around the valley. Just stick to routes with paved paths, and always check the forecast—those trails get pretty slippery.
Summer rolls in with lively festivals, too. Events like the Ropain (Rice Planting Festival in June) let you experience traditional farming celebrations up close.
Even when the rain stops, the hills around Kathmandu turn incredibly lush and green. If you love photography, you’ll spot some amazing scenes with clouds, rain, and those bright, vivid landscapes.