Climate Insights for Formosa

The climate in Formosa is warm and mild. The average annual temperature is 23°C and approximately 1352mm of precipitation falls per year. Formosa receives a notable amount of rainfall throughout the year, including during its driest month. 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: January, February, December. The coldest months are July, June, August, when temperatures can drop to 13°C.

Temperatures in Formosa vary considerably across the year, with a 21°C difference between the coldest and warmest months. The warmest month is January, when average highs reach 34°C and the mean temperature sits around 28°C. July is the coolest month, with minimum temperatures around 13°C and an average of 17°C. On average, daily temperatures fluctuate by about 10°C between overnight lows and afternoon highs. The sharpest temperature change occurs between April and May, with a 4°C shift in average temperatures.

Formosa is a fairly wet location, receiving approximately 1352mm of precipitation annually, which averages out to around 113mm per month. The wettest month is November, averaging 189mm of rainfall. October and December also tend to see above-average precipitation. The driest month is July, with just 54mm. That's 136mm less than November, the wettest month. Precipitation varies noticeably between seasons, with the second half (July to December) of the year generally seeing more rainfall.

Formosa is mildly breezy, with an average annual wind speed of 19km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is August, averaging 21km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in February, with average winds dropping to 16km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 5km/h between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 20km/h in winter, 21km/h in spring, 18km/h in summer, 17km/h in autumn.

It is currently autumn in Formosa, which began on March 20, 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 January at around 34°C, while the coldest stretch bottoms out in July near 13°C. Winter is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Formosa is during June, July, August and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 19°C with modest rainfall averaging 64mm per month. By contrast, January can be uncomfortably hot with temperatures reaching 34°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.

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.