Climate Insights for Formosa

The climate in Formosa is warm and mild. The average annual temperature is 20°C and approximately 101mm of precipitation falls per year. August is the wettest month, receiving around 33mm of rainfall. Formosa is in the Southern Hemisphere. The seasons are reversed — summer runs from December to February, while winter falls between June and August. The summer months are: October, November, June. The coldest months are December, August, July, when temperatures can drop to -2°C.

Formosa has a wide annual temperature range, spanning 39°C from the coldest to warmest months. October is the hottest month, with daytime highs reaching 37°C and an average of 31°C. The coldest month is December, when overnight lows fall to -2°C and the daily average is 6°C. On average, daily temperatures fluctuate by about 9°C between overnight lows and afternoon highs. The sharpest temperature change occurs between November and December, with a 18°C shift in average temperatures.

Formosa is a quite dry location, receiving approximately 101mm of precipitation annually, which averages out to around 8mm per month. The wettest month is August, averaging 33mm of rainfall. July and September also tend to see above-average precipitation. The driest month is May, with just 0mm. That's 33mm less than August, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.

Formosa is relatively calm, with an average annual wind speed of 3km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is January, averaging 5km/h, though still comfortable for most outdoor activities. The calmest conditions occur in December, with average winds dropping to 1km/h, making it an ideal period for wind-sensitive activities. Wind speeds vary significantly across the year, with a 4km/h difference between the calmest and windiest months. This level of variation is worth factoring into travel plans.

It is currently winter in Formosa, which began on June 21, 2026. Formosa is in the Southern Hemisphere, where the seasons are reversed — spring starts in September, summer in December, autumn in March, and winter in June. The warmest period peaks in October at around 37°C, while the coldest stretch bottoms out in December near -2°C. Spring is next, beginning on September 23, 2026 — 16 days from now.

The best time to visit Formosa is during January, February, March, April, May, June, July, September and November, when the weather is most comfortable for travellers. During these months, average temperatures hover around 20°C with modest rainfall averaging 7mm per month. By contrast, October can be uncomfortably hot with highs reaching 37°C, while December is the coldest period with lows dropping to -2°C. With minimal rainfall expected, you can pack light and plan outdoor activities with confidence.

The table below shows monthly climate averages for Formosa based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.