Monthly climate guide

Lisbon in August

In Lisbon, August sits in late summer, with a clear seasonal pattern 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.

Annual ranking snapshot

Ranked across 12 months

August in context

How it compares to the rest of the year in Lisbon.

Hottest (avg)
WARMEST
#1 / 12

The warmest month of the year.

Wettest (avg)
DRIER
#11 / 12

One of the drier months.

Daylight Hours
IN-BETWEEN
#4 / 12

Around the yearly average.

Windiest (avg)
WIND
#2 / 12

Among the windier months.

Highest UV
UV
#4 / 12

Near the middle of the yearly UV range.

Most Humid
HUMID
#12 / 12

One of the less humid months.

Climate normals

Four planning pillars

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

Day 15 selected

Median daytime highs across the month, with a softer low line.

Daily climate explorer for AugustMonthly trend chart for the selected climate metric, with the chosen day marked.152025303511631°C
Median temperatureMedian lowTypical range

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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)
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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 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.

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.

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