Sintra Temperature by Month
The average annual maximum temperature in Sintra, Lisbon Region, Portugal is 19°C (66°F), with daytime highs ranging from 15°C (59°F) in January to 23°C (73°F) in August. This page covers monthly averages, day-night differences, and how Sintra compares to cities worldwide.
Sintra Monthly Temperatures
The weather in Sintra changes moderately throughout the year, offering enough variation to appreciate each season. Nights are cooler, with lows ranging from 18°C (64°F) to 11°C (52°F).
The chart below illustrates the average maximum day and minimum night temperatures in Sintra by month:
The coldest point of the day usually falls between 4 AM and 6 AM, with temperatures peaking around 3 PM. August, the city's warmest month, gets 355 hours of sunshine.
The chart below shows the average temperature throughout the year:
Daily Historical Temperatures
50-year average (1976-2025)
Average high and low temperatures for each day of the month based on long-term records.
Average temperatures in May
Historical Sintra Temperatures: 1976-2026
Browse day-by-day temperature records for Sintra spanning 51 years. Select any month and year to see actual high and low temperatures recorded on each day.
Temperature: Sintra vs Portugal
The map below shows the annual temperature across Portugal. You can also select individual months if you want to compare a specific time of year.
very warm
warm
pleasant
moderate
cold
very cold
Sintra vs World: Temperature Compared
Sintra's average annual maximum temperature is 19°C (66°F). To put that in context, here's how it compares to a few well-known destinations:
Athens, Greece sits at 23°C (73°F) on average, with hot dry summers and mild winters characteristic of the Mediterranean.
On the cooler end, Oslo, Norway averages just 10°C (50°F) annually, with pleasant summers but long, cold winters.
Beijing, China averages 20°C (68°F) annually, but with big seasonal swings — very cold winters and hot summers.
Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.
What Does the Temperature Feel Like in Sintra?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In Sintra, January is the coolest month, with average highs of 15°C (59°F) and humidity around 82% — considered very high. In August, the warmest month, temperatures average 23°C (73°F) with 73% humidity — conditions that feel high. For a full picture, see our humidity page.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
Land Temperature: The average surface temperature across the Earth's land is around 14°C, but that figure hides enormous variation. In the Sahara, daytime temperatures can exceed 50°C. At the poles, averages fall below -30°C. Deserts are also notable for how quickly they cool at night — without moisture in the air to retain heat, temperatures can drop 30°C or more in just a few hours, making desert nights surprisingly cold.
Sea Temperature: The oceans average around 17°C at the surface — generally cooler than land. Because water absorbs and releases heat slowly, the sea acts as a buffer, keeping coastal climates more stable than inland areas. The deep ocean is a different story: below the sunlit upper layers, water stays near-freezing regardless of surface conditions.
Equatorial Regions: Near the equator, the sun is overhead year-round, producing consistent heat and fuelling tropical rainforests in places like the Amazon and Congo basins. Seasonal temperature variation is minimal, but these regions do experience distinct wet and dry seasons that shape their ecosystems.
Desert Regions: Desert temperatures swing wildly between seasons and even between day and night. The Sonoran Desert in North America can drop to 0°C on winter nights yet exceed 40°C on summer days. What all deserts share is very low rainfall — typically under 250mm per year.
Polar Regions: The Arctic and Antarctic experience extreme cold, with long stretches of darkness in winter and continuous daylight in summer. Arctic winter temperatures average around -30°C. In Antarctica's interior, it gets far colder — sometimes below -80°C in the coldest recorded spots.
Temperate Forests: Across North America, Europe, and East Asia, temperate forests see proper seasons — warm summers and cold winters, with average temperatures roughly between 5°C and 22°C depending on the time of year.
Mountain Regions: Temperature drops by roughly 6°C for every 1,000 metres of altitude. In ranges like the Andes or the Himalayas, that means you can move from temperate forest at lower elevations to permanent snow and ice at the peaks, all within a relatively short distance.
For more on Sintra's weather — including monthly rainfall, sunshine hours, and humidity — visit our Sintra climate page.
