Castelo Mendo Weather in September
September in Castelo Mendo typically sees daytime highs of 26°C (79°F) and nighttime lows of 13°C (55°F). Expect some rainfall during the month.
Rainfall in Castelo Mendo in September
Past climate data indicates that roughly 8 days will see rain, totalling around 43 mm (1.7 in) for the month. Neither particularly heavy nor particularly frequent, the rain this month is about average. A light jacket should be enough on most wet days.
Temperature in Castelo Mendo in September
September tends to be one of the perfect months in Castelo Mendo, with 26°C (79°F) in the afternoon and 13°C (55°F) overnight. This kind of day-to-night contrast is typical for this time of year. Nights cool down to 13°C (55°F), so a light jacket or extra layer is useful once the sun goes down. On the plus side, the cooler nights make for comfortable sleeping conditions.
Sunshine in Castelo Mendo in September
The month enjoys around 228 hours of sunshine, creating mostly sunny days with good weather conditions.If your ideal day consists of dry skies and pleasant temperatures, May, June, September and October typically offer the best circumstances for Castelo Mendo.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Portugal, check out our Castelo Mendo's climate page.
Castelo Mendo Temperature in September
Min Temperature
13°C (55°F)
Max Temperature
26°C (79°F)
Chance of Rain
27%
Precipitation
43 mm (1.7 in)
Rainy days
8 days
Humidity
63% *
Sunshine
228 hours *
Percentage Sunshine
*
Daily Historical Temperatures
44-year average (1976-2025)
Based on our historical records, temperatures in Castelo Mendo typically drop from around 23°C (73°F) at the start of September to approximately 19°C (66°F) by the end. Nights are cool, with lows typically ranging from 11°C (52°F) to 15°C (59°F).
Average temperatures in September
Daily Historical Precipitation
44-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Castelo Mendo in September
Browse day-by-day weather records for Castelo Mendo spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Castelo Mendo historical weather extremes in September
Based on weather observations in Castelo Mendo between 2001 and 2025, these are the recorded extremes during September.
- The warmest day in September was on September 6, 2016, with a maximum of 38°C (100°F).
- The coldest September day was on September 25, 2012, with a maximum of 11°C (52°F).
- Nighttime temperatures dropped to 3°C (37°F) on September 30, 2022, marking the coldest September night on record.
Best Places in Portugal in September
Find out more about the weather in Portugal and which places have the best travel conditions in this month. See all of Portugal in September →
perfect weather
pleasant
tolerable
unpleasant
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What to Wear in Castelo Mendo in September
Warm weather calls for comfortable, breathable clothing in September. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). Rain is likely on several days, so bring a good rain jacket. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.What To Do in Castelo Mendo in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Portugal, check out our Castelo Mendo's climate page.
Temperature Rainfall Sunshine Humidity
See the full Castelo Mendo climate overview or explore weather in Portugal.
