Sara and John say...
Taiwan is a tropical island of mild winters and hot, steamy summers. Rainfall is quite abundant, especially in the summer months, with northern areas (including the capital Taipei) seeing most rainfall through the year as a whole.
The summer months, particularly June to September, tend to be most humid and uncomfortable for visiting, with daytime temperatures ranging between the mid-20s Celsius at night to the mid-30s by day. Cloudy skies prevail, bringing downpours most days. However, even during the wet season, several days remain dry, with some breaks in the cloud allowing spells of hot sunshine. So sunscreen is a ‘must’.
The winter is drier and cooler, the former most notably in the south. Meanwhile, the cooler winters are most marked further north across Taiwan, where daytime temperatures fall back to the high teens Celsius.
The Penghu Islands are a popular summer beach destination, as rainfall tends to be less abundant than on the mainland.
In contrast, the more mountainous mainland settlements are a good deal cooler than low-lying areas. Indeed, some mountain valleys experience frost and snow during the coldest winter spells.
A word about typhoons. Taiwan is exposed to these storms in the period June to October, bringing the threat of damaging wind and rain. However it should be noted that the risk in any one place and time is still low for most of the year.