KATHMANDU, JUNE 21 The southwest monsoon has finally entered Nepal, arriving six days later than its usual schedule, the Department of Hydrology and Meteorology (DHM) said in its first Monsoon Onset Bulletin. According to the bulletin, the monsoon system entered parts of eastern Koshi Province on June 19, marked on the department's monsoon map as a blue zone covering the province's eastern belt. The average date for monsoon onset over eastern Nepal is June 13, meaning this year's arrival has been delayed by six days. The DHM said the monsoon currently remains weak and will take several more days to advance and cover the rest of the country. The Meteorological Forecasting Division said it will continue to monitor the system closely and issue regular updates, including its routine three-day weather bulletins, as the monsoon progresses westward across Nepal. The onset comes as much of the country continues to experience a mix of pre-monsoon weather patterns. According to DHM's 24-hour forecast issued Sunday morning, generally cloudy conditions are expected across the hilly and mountainous regions of the country, along with the Terai belt of Koshi Province, while Madhesh Province and the Terai areas of Bagmati and Gandaki are likely to see partly cloudy skies. The Terai regions of Lumbini and Sudurpaschim, meanwhile, are expected to remain mainly fair, with heat wave conditions forecast in Dhangadi and Nepalgunj, where maximum temperatures could touch 41 degrees Celsius. Thunderstorms with moderate rain are expected at several places in the hilly and mountainous areas of Koshi, Bagmati and Gandaki provinces, with isolated heavy rainfall likely in the hilly and Terai areas of Koshi Province. Kathmandu is forecast to see moderate rain with thundershowers through the day and into the night, with a 60 percent chance of rainfall after dark and minimum temperatures expected to dip to 19-21 degrees Celsius. The DHM said parts of Koshi Province are currently under the influence of monsoon winds, while the rest of the country remains under the influence of westerly and local wind patterns. The department has urged the public to follow its regular weather bulletins for updates as the monsoon continues its advance across Nepal in the coming days.