The temperature of Biratnagar swings from mild winter mornings to scorching summer afternoons. As the largest city in the eastern Terai, Biratnagar sits low on the plains and feels the full force of the subtropical heat.
So what should you expect across the year? Below, I explain the seasons, the monsoon, the humidity, and why nearby Nepalgunj often records higher peaks than Biratnagar.
What is the temperature of Biratnagar through the year?
Biratnagar has a humid subtropical climate. In practice, that means hot, sticky summers and gentle, dry winters. Daytime readings generally range from the mid-teens in the coldest months to the high 30s Celsius at the peak of summer.
April and May bring the hottest, driest heat. During this pre-monsoon stretch, afternoons climb into the high 30s and sometimes brush 40°C. By contrast, January stays mild, with comfortable days and cool nights. Therefore the city never sees snow or frost, unlike Nepal's hill towns.
Because the city lies in the plains, the heat feels heavy. Humidity adds to that. For more on the city's setting, see where Biratnagar is located on the map of Nepal, which explains its low Terai elevation.
Summer, monsoon and winter seasons
The year splits into clear phases. First comes a hot, dry summer from roughly March to May. Then the monsoon arrives. Finally, a mild winter settles in from late November.
Summer is the toughest season for visitors. Strong sun, dry winds, and rising humidity make midday outdoor work hard. Locals often start early and rest through the hottest hours. Even so, evenings can offer a little relief.
Winter, on the other hand, is pleasant. Days feel warm in the sun, while mornings turn cool and sometimes foggy. As a result, December and January are the most comfortable months to walk the city. The famous Biratnagar Jute Mill, a landmark of the region's industrial history, sits in this same warm plain.
When will it rain in Biratnagar?
Rain in Biratnagar follows the monsoon. The wet season runs roughly from June to September, when moist air sweeps in from the Bay of Bengal. July is typically the wettest month, bringing heavy downpours and the highest rainfall of the year.
During the monsoon, streets can flood quickly and humidity stays high. Importantly, the rain also cools the fierce pre-monsoon heat. For official forecasts and seasonal outlooks, you can check the Department of Hydrology and Meteorology, Nepal's national weather authority.
After September, the rain fades fast. October and November turn dry and clear. Generally, the driest stretch falls between November and February, with very little rainfall and bright skies.
How humid does Biratnagar get?
Humidity (आर्द्रता) is the defining feature of Biratnagar's weather. The eastern Terai receives more moisture than the far west, so the air stays damp for much of the year.
Relative humidity climbs sharply during the monsoon and remains noticeable even in the warmer dry months. Consequently, a 36°C day in Biratnagar can feel hotter than the same reading in a drier town. Winter, by contrast, brings lower humidity and that crisp, foggy morning air the plains are known for.
Why is it hotter in Nepalgunj than Biratnagar?
People often ask why Nepalgunj records higher temperatures than Biratnagar. Both cities sit low in the Terai, yet Nepalgunj regularly tops the national heat charts. In recent years, Nepalgunj has hit around 44°C, while Biratnagar's peaks have stayed closer to 41°C.
The main reason is location. Nepalgunj lies in the drier far-western plains, where the air holds less moisture. Dry heat builds faster and pushes the thermometer higher. Biratnagar, in the more humid east, traps moisture instead, which slightly caps the maximum reading.
Still, do not mistake lower peaks for comfort. Because Biratnagar is so humid, its heat can feel just as draining. To understand the region better, read about which province Biratnagar sits in and which district covers the city. Both shape its place in the eastern Terai.
Best time to visit Biratnagar
The best time to visit Biratnagar runs from October to March. During these months, the weather stays dry, the skies clear, and temperatures feel comfortable for travel and outdoor work.
October and November are ideal. The monsoon has passed, the plains turn green, and the air feels fresh. February and early March also suit visitors well, just before the summer heat returns. By contrast, April to June can be uncomfortably hot, and July to September brings heavy rain.
If you are travelling from the capital, plan around the seasons. You can see how long the trip takes in this guide on how far Biratnagar is from Kathmandu. There is plenty to explore once you arrive, as covered in what Biratnagar is famous for.
Why local climate matters for daily life and work
The weather shapes how Biratnagar lives and works. Court hearings, business meetings, and document signings all bend around the seasons. During peak summer and the monsoon, schedules often shift to cooler hours.
As a lawyer in Biratnagar, I see this rhythm every day. Whether you are a resident or a visitor, knowing the climate helps you plan around it. From property dealings to court appearances, timing matters in this part of Nepal.
I am Rupesh Koirala, an advocate practising in Eastern Nepal and the principal of Sulav Legal Services. If you need clear, reliable legal help in Biratnagar, from property law to dispute resolution, get in touch with our team today. Reach out and we will guide you through every step.