The warmest month of the year.
August in context
How it compares to the rest of the year in Lisbon.
One of the drier months.
Around the yearly average.
Among the windier months.
Near the middle of the yearly UV range.
One of the less humid months.
Monthly climate breakdown
A detailed look at the typical climate conditions for August.
Thermal profile
Temperature
Typical daytime high
- Nighttime low
-
- Feels like (avg)
-
Light window
Sunshine
13.6 h
Average daylight
- UV index (max)
- 8
- Typical sun hours
- 05:51 - 19:29
Wet-day pattern
Rain & Snow
Typical rainfall
- Rainy days
- 2 days
- Cloud cover (avg)
- 25%
Air feel
Humidity & Wind
70%
Average humidity
- Wind (avg)
-
- Wind (max gusts)
-
Historical daily baseline
Daily climate explorer
Pick a day to inspect the usual conditions through August in Lisbon. Based on a 30-year historical climate baseline, not a forecast.
Primary control
Select a day
Scroll to compare daily conditions. The summary updates with your selection.
Secondary context
Monthly trend
Median daytime highs across the month, with a softer low line.
Day 15 selected for August. Temperature 26.3°C.
Historical disruption baseline
Typical disruptions in August
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in August.
Hot days Measures: Hot days (>=30C). Observed about 19% of days (5.9 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
5.9 days / month
- Share of days
- ~19% of days
- Upper edge
- Up to ~37°C (P95)
Why this matters
Hot days are possible on ~6 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Hot feels-like days Measures: Hot feels-like days (>=32C). Observed about 19% of days (5.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
5.8 days / month
- Share of days
- ~19% of days
- Upper edge
- Up to ~39°C (P95)
Why this matters
Feels-like heat >=32C is possible on ~6 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Very hot feels-like Measures: Very hot feels-like days (>=35C). Observed about 6% of days (2.0 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
2.0 days / month
- Share of days
- ~6% of days
- Upper edge
- Up to ~40°C (P95)
Why this matters
Very hot feels-like conditions are possible on ~2 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Very hot days Measures: Very hot days (>=35C). Observed about 2% of days (0.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.5 days / month
- Share of days
- ~2% of days
- Upper edge
- Up to ~41°C (P95)
Why this matters
Very hot days are possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heatwave run Measures: Heatwave runs (>=3 hot days). Observed about 0.8 days/month in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.8 days / month
- Share of days
- —
- Upper edge
- Up to ~37°C (P95)
Why this matters
Heatwave runs are possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Feels-like heatwave Measures: Feels-like heatwave runs (>=3 days). Observed about 0.8 days/month in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.8 days / month
- Share of days
- —
- Upper edge
- Up to ~39°C (P95)
Why this matters
Feels-like heatwave runs are possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Show all disruptions (13 more)
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 1% of days (0.4 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.4 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~65km/h (P95)
Why this matters
Strong gusts are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Muggy days Measures: Muggy days (dew point >=20C). Observed about 1% of days (0.2 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.2 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~20°C (P95)
Why this matters
Muggy conditions are possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Gusty days Measures: Gusty days (>=40 km/h). Observed about 56% of days (17.3 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
17.3 days / month
- Share of days
- ~56% of days
- Upper edge
- Up to ~57km/h (P95)
Why this matters
Gusty conditions are possible on ~17 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Breezy days Measures: Breezy days (mean wind >=25 km/h). Observed about 12% of days (3.7 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
3.7 days / month
- Share of days
- ~12% of days
- Upper edge
- Up to ~32km/h (P95)
Why this matters
Breezy conditions are possible on ~4 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
High humidity Measures: High humidity days (RH >=80%). Observed about 12% of days (3.6 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
3.6 days / month
- Share of days
- ~12% of days
- Upper edge
- Up to ~87% (P95)
Why this matters
High humidity is possible on ~4 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 10% of days (3.1 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
3.1 days / month
- Share of days
- ~10% of days
- Upper edge
- Up to ~94% (P95)
Why this matters
Cloudy skies are possible on ~3 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humid days Measures: Humid days (dew point >=18C). Observed about 10% of days (3.1 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
3.1 days / month
- Share of days
- ~10% of days
- Upper edge
- Up to ~20°C (P95)
Why this matters
Humid conditions are possible on ~3 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Wet days Measures: Wet days (>=0.1mm). Observed about 9% of days (2.8 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
2.8 days / month
- Share of days
- ~9% of days
- Upper edge
- Up to ~4.8mm (P95)
Why this matters
Measurable rain is possible on ~3 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 5% of days (1.6 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.6 days / month
- Share of days
- ~5% of days
- Upper edge
- Up to ~11h (P95)
Why this matters
Several rainy hours are possible on ~2 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Warm nights Measures: Warm nights (min >=22C). Observed about 5% of days (1.5 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.5 days / month
- Share of days
- ~5% of days
- Upper edge
- Up to ~25°C (P95)
Why this matters
Warm nights are possible on ~2 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 3% of days (0.9 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.9 days / month
- Share of days
- ~3% of days
- Upper edge
- Up to ~98% (P95)
Why this matters
Mostly cloudy skies are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 2% of days (0.7 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.7 days / month
- Share of days
- ~2% of days
- Upper edge
- Up to ~12h (P95)
Why this matters
Wet-most-of-day conditions are possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heat stress risk Measures: High heat stress days. Observed about 1% of days (0.4 days/month) in August. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.4 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~41°C (P95)
Why this matters
Heat stress is possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Travel planning FAQ
Frequently asked questions
Quick answers to the weather questions you ask the most.
Is August a good time to visit Lisbon?
Typical August days in Lisbon reach highs of 27°C (81°F) with nights around 19°C (66°F). It usually feels warm by day and mild after dark. It is one of the drier months, which suits outdoor exploring and sightseeing.
What are temperatures like in August?
Daytime temperatures in August typically peak near 27°C (81°F), while nights drop to around 19°C (66°F). Expect warm afternoons and mild evenings.
How much does it rain in August?
Rainfall in August averages 4 mm (0.16 in) across roughly 2 days. Overall it is a mostly dry time of year, so showers are usually brief rather than all-day downpours.
How many hours of daylight are there in August?
You can expect about 14 hours of daylight in August. Sunrise is typically around 05:51 and sunset near 19:29. You get long days with comfortable amounts of daylight.
How strong is the sun in August?
UV levels frequently reach very high levels (around 8), so strong sun protection is essential, especially around midday.
Is it windy in August?
In August, average wind speeds are around 17 km/h (11 mph), with gusts on the windiest days reaching about 52 km/h (32 mph). On the ground, it is it can feel quite windy at times, particularly when weather systems move through.