Climate Insights for Castelo Branco

The climate in Castelo Branco is temperate. The average annual temperature is 17°C and approximately 515mm of precipitation falls per year. October is the wettest month, receiving around 81mm of rainfall. Castelo Branco is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, July, June. The coldest months are January, February, December, when temperatures can drop to 5°C.

Temperatures in Castelo Branco vary considerably across the year, with a 29°C difference between the coldest and warmest months. The warmest month is August, when average highs reach 34°C and the mean temperature sits around 26°C. January is the coolest month, with minimum temperatures around 5°C and an average of 9°C. On average, daily temperatures fluctuate by about 11°C between overnight lows and afternoon highs. The sharpest temperature change occurs between October and November, with a 5°C shift in average temperatures.

Castelo Branco is a relatively dry area, receiving approximately 515mm of precipitation annually, which averages out to around 43mm per month. The wettest month is October, averaging 81mm of rainfall. December and March also tend to see above-average precipitation. The driest month is August, with just 2mm. That's 79mm less than October, 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.

Castelo Branco is mildly breezy, with an average annual wind speed of 15km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is March, averaging 17km/h, though still comfortable for most outdoor activities. The calmest conditions occur in September, with average winds dropping to 14km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 3km/h between the calmest and windiest months.

It is currently spring in Castelo Branco, which began on March 20, 2026. Castelo Branco is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in August at around 34°C, while the coldest stretch bottoms out in January near 5°C. Summer is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit Castelo Branco is during April, May, June, September and October, when the weather is most comfortable for travellers. During these months, average temperatures hover around 19°C with modest rainfall averaging 44mm per month. By contrast, August can be uncomfortably hot with highs reaching 34°C, while January is the coldest period with lows dropping to 5°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 Castelo Branco 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.