Country Overview For Portugal
The climate in Portugal is typically maritime temperate; cool and rainy in north, warmer and drier in south. The terrain: mountainous north of the Tagus River, rolling plains in south. For Lisbon in January the daily average maximum temperatures is 14°C with the average minimum 6°C, while in June the average maximum is 23°C with a minimum of 14°C. The wettest month for Lisbon is November with an average of 159.9mm of precipitation falling while the driest month is July with 17.4mm falling.
HISTORICAL MONTHLY AVERAGES FOR AUGUST
The information presented below gives detailed historical monthly average weather conditions along with exceptional weather occurrences. To maintain relevance to current weather trends the displayed information has been calculated using data collected over the past two decades. The climate profile is taken from closest available data source to Sintra.
Throughout the month of August daytime temperatures will generally reach highs of around 26°C that's about 79°F. At night the average minimum temperature drops down to around 17°C, that's 62°F.
In recent times the highest recorded temperature in August has been 42°C that's 107°F, with the lowest recorded temperature 11°C, about 53°F.
The average daily relative humidity for August is around 67%.
The Heat Index is a measure of how hot it feels when relative humidity is added to actual air temperature. From this a comfort level is calculated providing categories on how heat conditions might adversely affect someone.
Comfort Levels: Given average maximum temperatures and humidity levels generally you should not anticipate any discomfort from heat (see heat index for more information).
The average monthly amount of precipitation has been recorded at around 8 mm, that's 0 inches. Throughout the month you can expect to see rain or drizzle falling on 3 days of the month.
Estimated Hours of Sunshine per Day
We calculate sunshine hours per day using our past forecast data. For August expect the sun to shine for an average of 12 hours per day. This represents the average number of hours in the daytime that the sun is visible and not obscured by cloud e.g. the average number of hours the sun is actually out and shining. Note we calculate hours of sunshine per day using our past forecast data, not observation data, thus it is an estimate and not actual.
The average daily wind speed in August has been around 15 km/h, that’s the equivalent to about 10 mph, or 8 knots. In recent years the maximum sustained wind speed has reached 46 km/h, that’s the equivalent of around 29 mph, or 25 knots.
On average the month of August is affected by foggy conditions on 2 days.
SWIMMING AND WATER TEMPERATURE
The temperature of water an individual will feel comfortable in is very much personal preference. What feels unbearably cold to one person for a swim might be fine for another. We have created our own Swimming Water Temperature Index offering a guide to water temperature and comfort levels for swimming;
In August, for the nearest coastal location, the temperature of the sea averages around 21°C, that's 70° Fahrenheit. Our index indicates for swimming this is considered fairly warm and should be enjoyed by most, though some people may still find it a little too cool for their liking.
YEARLY TRENDS: WEATHER AVERAGES & EXTREMES
The following charts show yearly weather trends with information on monthly weather averages and extremes.
The chart below plots the average high and low temperature for each month of the year. It also shows the maximum and minimum recorded temperatures.
The chart below plots the average monthly precipitation amount.
The chart below plots the average number of days in any month that you can expect to see rain falling.
The chart below plots the average daily wind speed you can expect for any month. It also shows the maximum recorded sustained wind speed for each month.