Alter do Chão Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Alter do Chão, Alentejo, Portugal. These values are calculated using 30 years of data (1990–2020) to ensure accuracy. Let's now guide you through the details for a complete overview.

Generally, Alter do Chão has a moderate amount of precipitation, averaging 615 mm (24 in) of rainfall annually. However, it does experience a distinct dry season during certain months. Take a look at our detailed charts below to see the seasonal variation.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

Significant seasonal changes in precipitation occur throughout the year. During the wettest month, October receives substantial rainfall, averaging 84 mm (3.3 in) of precipitation, recorded across 11 rainy days.

In contrast, the driest month, July brings less rainfall, with 4.3 mm (0.2 in) over 3 rainy days.

October, the wettest month, has a maximum daytime temperature of 24°C (75°F). During the driest month July you can expect a temperature of 33°C (91°F). For more detailed insights into the city's temperatures, visit our Alter do Chão Temperature page.

Alter do Chão's average annual precipitation is 615 mm (24 in). Let's compare this to some popular worldwide tourist destinations:

New York City, USA, receives 1276 mm (50 in) of rainfall annually, with precipitation evenly distributed throughout the year.

Beijing, China, receives 560 mm (22 in) of annual precipitation, concentrated in the summer months.

Perth, Australia, receives 565 mm (22 in) of rainfall annually, mostly during the winter months.

Singapore, situated near the equator, gets 2581 mm (102 in) of rainfall annually, with no distinct dry season and consistent monthly precipitation.

Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.

Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.

The proximity of a location to a large body of water can significantly affect its rainfall patterns:

• Ocean Influence: Coastal regions typically receive more rainfall due to the presence of moisture-laden winds from the ocean. These regions tend to have more humid climates and experience more frequent precipitation, especially in winter.
• Continental Climates: Areas further from the sea, such as inland or continental regions, experience less frequent rainfall and more extreme seasonal variations in precipitation.

• Mawsynram in India is noted as being the wettest place on earth, with over 11 meters (36 feet) of rain falling every year.
• In contrast, Antofagasta in Chile is among the driest places on the planet, getting less than 0.1mm (0.004 inches) per year, with some years recording virtually no rainfall.
• Nearly 1,650 thunderstorm cells are estimated over the planet at any given time.

For more detailed information about Alter do Chão's weather, including sunshine hours, humidity levels, and temperature data, visit our Alter do Chão Climate page.