The climate in Castelo Branco during September can be summarized as warm and reasonably dry.
September is in the fall / autumn in Castelo Branco and is typically the 3rd warmest month of the year. Daytime maximum temperatures average around a comfortable 28°C (82°F), whilst at night 16°C (61°F) is normal.
| Daytime temperature | 28°C 82.3°F | 
|---|---|
| Nightly temperature | 16.3°C 61.3°F | 
| Average temperature | 22.1°C 71.8°F | 
| Daily sunshine | 8.7 hrs | 
| Avg rainfall | 33 mm 1.3 ins | 
| Rainy days | 7 days | 
| Sea temperature | 19.9°C 67.8°F | 
| Humidity | 57% | 
| Windspeed | 11.2kph 7 mph | 
On average September is the 3rd driest month of the year in Castelo Branco with around 33mm 1.3 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 7 days, although this may vary considerably.
On the flip side this corresponds to an average of 8.7 hours of sunshine per day.
 
				 
						 
						The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Castelo Branco in September 2025.
Best places to visit in September
| Hottest month: | July | 30.5°C 86.9°F | 
|---|---|---|
| Driest month: | July | 3mm 0.1ins | 
| Sunniest month: | August | 11.6hrs | 
| Coldest month: | January | 13.1°C 55.6°F | 
| Wettest month: | February | 101mm 4ins | 
 
	 
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