Avg High
Lisbon in August
Avg Low
Rain
Daylight
14h
What to expect
In Lisbon, August sits in late summer, with a clear seasonal rhythm running through the month. Most days feel warm without being relentless, with evenings that ease back comfortably. You get long daylight windows for full-day exploring. Comfort is usually predictable, so a standard day plan works well.
August in context
How it compares to the rest of the year in Lisbon.
Hottest (avg)
#1 / 12
Wettest (avg)
#11 / 12
Daylight Hours
#4 / 12
Windiest (avg)
#2 / 12
Highest UV
#4 / 12
Most Humid
#12 / 12
Monthly climate breakdown
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight hours
- 13.6 h
- UV index (max)
- 8
- Typical sun hours
- 05:51 - 19:29
Rain & Snow
- Total rain
-
- Rainy days
- 2 days
- Cloud cover (avg)
- 25%
Humidity & Wind
- Humidity (avg)
- 70%
- Wind (avg)
-
- Wind (max gusts)
-
Daily climate explorer
Day 15 selected for August. Typical high 26.3°C and low 18.5°C.
Typical disruptions in August
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in August.
Heat High impact
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.
5.9 days / month
~19% of days
Why this matters
- Expected days 5.9 days / month
- Probability ~19% of days
- Intensity Up to ~37°C (P95)
Hot days are possible on ~6 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
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.
5.8 days / month
~19% of days
Why this matters
- Expected days 5.8 days / month
- Probability ~19% of days
- Intensity Up to ~39°C (P95)
Feels-like heat >=32C is possible on ~6 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
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.
2.0 days / month
~6% of days
Why this matters
- Expected days 2.0 days / month
- Probability ~6% of days
- Intensity Up to ~40°C (P95)
Very hot feels-like conditions are possible on ~2 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
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.
0.5 days / month
~2% of days
Why this matters
- Expected days 0.5 days / month
- Probability ~2% of days
- Intensity Up to ~41°C (P95)
Very hot days are possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat Minor
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.
0.8 days / month
Probability unavailable
Why this matters
- Expected days 0.8 days / month
- Probability —
- Intensity Up to ~37°C (P95)
Heatwave runs are possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat Minor
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.
0.8 days / month
Probability unavailable
Why this matters
- Expected days 0.8 days / month
- Probability —
- Intensity Up to ~39°C (P95)
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)
Wind Moderate
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.
0.4 days / month
~1% of days
Why this matters
- Expected days 0.4 days / month
- Probability ~1% of days
- Intensity Up to ~65km/h (P95)
Strong gusts are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Humidity Moderate
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.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~20°C (P95)
Muggy conditions are possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wind Minor
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.
17.3 days / month
~56% of days
Why this matters
- Expected days 17.3 days / month
- Probability ~56% of days
- Intensity Up to ~57km/h (P95)
Gusty conditions are possible on ~17 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Wind Minor
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.
3.7 days / month
~12% of days
Why this matters
- Expected days 3.7 days / month
- Probability ~12% of days
- Intensity Up to ~32km/h (P95)
Breezy conditions are possible on ~4 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Humidity Minor
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.
3.6 days / month
~12% of days
Why this matters
- Expected days 3.6 days / month
- Probability ~12% of days
- Intensity Up to ~87% (P95)
High humidity is possible on ~4 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Cloud Minor
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.
3.1 days / month
~10% of days
Why this matters
- Expected days 3.1 days / month
- Probability ~10% of days
- Intensity Up to ~94% (P95)
Cloudy skies are possible on ~3 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humidity Minor
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.
3.1 days / month
~10% of days
Why this matters
- Expected days 3.1 days / month
- Probability ~10% of days
- Intensity Up to ~20°C (P95)
Humid conditions are possible on ~3 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Rain Minor
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.
2.8 days / month
~9% of days
Why this matters
- Expected days 2.8 days / month
- Probability ~9% of days
- Intensity Up to ~4.8mm (P95)
Measurable rain is possible on ~3 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
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.
1.6 days / month
~5% of days
Why this matters
- Expected days 1.6 days / month
- Probability ~5% of days
- Intensity Up to ~11h (P95)
Several rainy hours are possible on ~2 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heat Minor
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.
1.5 days / month
~5% of days
Why this matters
- Expected days 1.5 days / month
- Probability ~5% of days
- Intensity Up to ~25°C (P95)
Warm nights are possible on ~2 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
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.
0.9 days / month
~3% of days
Why this matters
- Expected days 0.9 days / month
- Probability ~3% of days
- Intensity Up to ~98% (P95)
Mostly cloudy skies are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
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.
0.7 days / month
~2% of days
Why this matters
- Expected days 0.7 days / month
- Probability ~2% of days
- Intensity Up to ~12h (P95)
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 Minor
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.
0.4 days / month
~1% of days
Why this matters
- Expected days 0.4 days / month
- Probability ~1% of days
- Intensity Up to ~41°C (P95)
Heat stress is possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Frequently asked questions
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.