An upcoming surge of cooler air is expected to affect Taiwan, bringing a temperature drop to parts of the region. The shift follows a period of lingering heat that prompted official warnings across multiple regions, marking a sharp transition toward autumn weather conditions.
The Central Weather Administration issued high-temperature orange alerts for seven administrative districts, including Taipei City, New Taipei City, Changhua County, Nantou County, Yunlin County, Tainan City, and Pingtung County. Forecasters warned that ultraviolet radiation levels remained high around midday, while localized areas faced a chance of temperatures reaching 36 degrees Celsius.
Central University atmospheric sciences adjunct associate professor Wu Derong noted via a weather commentary column that daytime conditions across central and southern regions remained hot under partly cloudy skies, with isolated afternoon brief showers appearing only over mountain areas. However, that pattern is about to break as seasonal shifts take hold across the island.
Monsoon Shifts and Temperature Drops
A sequence of weather systems will alter conditions significantly over the coming days, starting with a weak initial surge of northerly winds. Taiwan Disaster Management Engineering Technology Consulting Company director Jia Xinxing reported that the first weak cool air mass arrives, bringing slightly lower temperatures and increased precipitation probabilities to areas from Taoyuan northwards alongside Yilan.
A stronger northeast monsoon will follow, with forecasters tracking its arrival to drive a profound drop in thermal readings across northern regions. Taipei’s daytime highs are projected to slide from recent peaks down to 25 to 27 degrees Celsius, while nighttime and early morning lows retreat toward 20 degrees Celsius. In open northern terrain, thermometers could dip as low as 18 degrees Celsius.
Precipitation is expected to ramp up correspondingly across northern and eastern sectors, including Keelung North Coast, Yilan, and Hualien. Forecasters highlighted Yilan as a zone requiring heightened attention for localized heavy downpours, prompting recommendations for commuters and evening travelers to start preparing light jackets.
Typhoon Choi-Wan Development
While domestic conditions transition toward cooler and wetter patterns, maritime activity in the western Pacific has produced the 26th tropical storm of the season. The Central Weather Administration confirmed that a tropical depression situated over ocean waters northeast of Guam intensified into a mild typhoon named Choi-Wan.
European forecasting model ensemble simulations suggest the system will expand in scale and strength as it tracks westward before turning northward toward the ocean waters southeast of Japan. Forecasters emphasized that direct impact upon Taiwan remains extremely low, though meteorological teams continue monitoring its trajectory.
Weekly Weather Outlook
The transition spans several distinct phases, bringing shifting conditions from high heat to crisp, clear air:
| Timeframe | Weather Phenomenon | Temperature & Regional Impact |
|---|---|---|
| Today (Oct 1) | Partly cloudy; isolated mountain afternoon showers | 7 areas under orange heat alerts; 36C possible locally |
| Oct 2 – Oct 4 | Moisture increases; north and east turn rainy | Temperatures edge down; central and south stay hot |
| Oct 5 – Oct 6 | Northeast monsoon strengthens; windward rain peaks | Northern Taiwan cools notably; air dries gradually |
| Oct 7 | Skies clear nationwide; morning radiation cooling | Wide diurnal temperature range; crisp morning lows |
By October 7, weather conditions across the island are expected to improve as skies clear. Clear overnight conditions will encourage radiation cooling, resulting in crisp morning lows and a pronounced expansion in daily temperature ranges.
