Your August weather guide
HotWeather in Istanbul in August
August is a good time to visit Istanbul if you want hot days, warm evenings and sea temperatures suited to swimming. Expect daytime highs around 28°C, nights around 22°C and sea temperatures of 24.4°C. The catch is that this is Istanbul's warmest month, so a packed schedule outdoors may feel tiring. It suits travellers happy to slow down at midday rather than those who prefer cool weather for exploring a city.
Long-term climate averages for Istanbul, not a forecast · 1991-2020
Istanbul, month by month
Your snapshot
At a glance
The useful details for Istanbul.
- Average daytime high
- 27.9°C
- 9 in 10 days stay below 31°C
- Average night-time low
- 21.8°C
- coldest 10% of nights: 20°C or lower
- Compared with London
- +6.5°C
- London averages 21.4°C in August
- Sea temperature
- 24.4°C
- year to year: 24°C to 25°C
- Sunshine per day (est.)
- 10.8h
- 79% of 13.6 h of daylight
- Rainy days (1 mm+)
- 3
- 20 mm over the month
- Humidity
- 70%
- Days over 25°C
- 91%
- 19% over 30°C
- Record high 1991-2020
- 34.9°C
- 2002-08-12
- Record low 1991-2020
- 16.0°C
- 2019-08-19
- Flight from London
- ≈ 3 h 54 min
- 2491 km, short-haul (estimate for a direct flight)
Records are observed extremes within 1991-2020, not typical holiday conditions. Warm-day percentages are shares of days, not day counts.
How August compares
August is the 1st warmest month of the year in Istanbul and ranks 87th of 134 destinations we compare for August - see where else is hot in August. Within Turkey it is 16th of 18 (Turkey in August). Against London's average high of 21.4°C in August, Istanbul is 6.5°C warmer by day and 8.3°C warmer at night.
Daytime and night-time in August
The typical August day in Istanbul peaks at 27.9°C, but that is an average: the warmest 10% of days reach 30.7°C or more. About 91% of days top 25°C and 1 in 5 pass 30°C. Nights average 21.8°C; one night in ten drops to 19.7°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest August day here reached 34.9°C (2002-08-12) and the coldest night 16.0°C (2019-08-19).
Rain in August
Some rain (4-8 rainy days): about 3 days with 1 mm or more, 20 mm in total. Year to year it varies a lot - the wettest August was 1997 with 144 mm, the driest 1998 with 0 mm. Humidity averages 70%.
Sea temperature in August
The sea averages 24.4°C - warm enough to swim (22°c+). Depending on the year it ranges from 23.6°C to 25.4°C. This is the warmest the sea gets here all year.
Sunshine and daylight
Around 10.8 hours of sunshine a day (estimated from cloud cover), 13.6 hours of daylight: the sun rises about 06:14 and sets about 20:03 local time in mid-August. Average cloud cover is 21%.
Is August a good time to visit Istanbul?
Yes - it is one of the better months: hot days, manageable rain and long sunny days. The best months for Istanbul on our scoring are August, July, June; months averaging 25°C or more: Jul, Aug.
Plan around the heat, not just the average
Light, breathable clothing is the sensible starting point, with comfortable footwear and sun protection for time outdoors. Highs around 28°C sound manageable, but 19% of August days reach 30°C, so leave room to change your plans when it feels hotter. Humidity of 70% can add to the sticky feeling, particularly if you are walking for long stretches. Put more demanding outings earlier in the day and use the midday heat for a shaded break or time indoors. Nights average around 22°C, so do not count on a sharply cooler evening to recover; accommodation with cooling is a sensible priority if you struggle to sleep in warmth.
Plenty of sunshine, with a small rain risk
August gives you plenty of scope for outdoor plans, with about 10.8 hours of sunshine a day. That is useful for spreading activities across the day instead of trying to fit everything into the hottest hours. Rain is a smaller concern than heat: there are about 3 rainy days during the month, so waterproof clothing need not dominate your packing. A compact umbrella is still sensible, and keeping an indoor option in mind avoids relying on an entirely dry trip. Choose light layers rather than heavy rainwear, and keep water and sun protection handy even when you are only heading out for a casual walk.
A little perspective
Istanbul through the year
August is highlighted. See how it compares with the rest of the year.
| Month | Day | Night | Sea | Sun/day | Rain mm | Rainy days | Days 25°C+ |
|---|---|---|---|---|---|---|---|
| January | 8.2°C | 4.1°C | 8.4°C | 3.1 | 85 | 12 | 0% |
| February | 8.8°C | 4.1°C | 7.3°C | 3.7 | 71 | 11 | 0% |
| March | 11.0°C | 5.6°C | 7.8°C | 4.8 | 72 | 11 | 0% |
| April | 15.1°C | 8.8°C | 10.2°C | 6.2 | 47 | 8 | 0% |
| May | 20.0°C | 13.6°C | 15.4°C | 7.8 | 36 | 6 | 6% |
| Junebest | 24.9°C | 18.4°C | 20.8°C | 10.4 | 35 | 6 | 50% |
| Julybest | 27.6°C | 21.1°C | 23.5°C | 11.8 | 19 | 4 | 88% |
| AugustSelectedbest | 27.9°C | 21.8°C | 24.4°C | 10.8 | 20 | 3 | 91% |
| September | 24.1°C | 18.5°C | 22.5°C | 8.2 | 45 | 6 | 42% |
| October | 19.2°C | 14.5°C | 18.9°C | 5.3 | 78 | 9 | 4% |
| November | 14.4°C | 10.0°C | 14.8°C | 3.9 | 72 | 10 | 0% |
| December | 10.2°C | 6.3°C | 11.1°C | 3.0 | 97 | 13 | 0% |
Day = average daytime high, night = average night-time low, 1991-2020.Sun is hours per day; rainy days count 1 mm or more.
Day, night and sea
Monthly average temperatures, 1991-2020
- Day
- Night
- Sea
Best months here
On warmth, low rainfall and sunshine, start with these.
Keep exploring
Similar in August
Closest matches on daytime temperature, sea temperature and sunshine, in other countries.
Bulgaria · 27°C by day · sea 25°C
Sunny Beach
Greece · 28°C by day · sea 26°C
Thassos
Spain · 29°C by day · sea 23°C
Malaga
Spain · 28°C by day · sea 23°C
Gran Canaria
Croatia · 29°C by day · sea 26°C
Dubrovnik
A little more detail
Istanbul in August FAQs
Plain answers, grounded in the averages.
Is Istanbul hot in August?
Istanbul is hot in August: the average daytime high is 27.9°C and nights average 21.8°C. About 91% of August days reach 25°C or more.
Can you swim in the sea in Istanbul in August?
The sea around Istanbul averages 24.4°C in August, which is warm enough for most people to swim comfortably. Between 1991 and 2020 it ranged from 24°C to 25°C depending on the year.
How much does it rain in Istanbul in August?
Istanbul sees about 3 rainy days (1 mm or more) and 20 mm of rain in a typical August. The wettest August between 1991 and 2020 was 1997 (144 mm) and the driest was 1998 (0 mm).
How sunny is Istanbul in August?
Istanbul gets around 10.8 hours of sunshine a day in August out of 13.6 hours of daylight (estimated from average cloud cover).
How does Istanbul compare with the UK in August?
Istanbul is on average 6.5°C warmer than London by day in August (27.9°C against 21.4°C).
What is the hottest August on record in Istanbul?
Between 1991 and 2020 the hottest August day in Istanbul reached 34.9°C on 2002-08-12, and the coldest night dropped to 16.0°C on 2019-08-19.
How much warmer is Istanbul than London in August?
Istanbul's average daytime high is 27.9°C, compared with London's 21.4°C, a difference of 6.5°C. That is enough to change how you plan a day outdoors: allow more shade breaks and favour lighter clothing than you might at home.
Is the sea warm enough for swimming?
Yes. The sea averages 24.4°C in August, with a year-to-year range of 24°C to 25°C. That puts it comfortably in the swimming category, making August a sensible choice if you want to include swimming alongside your city stay.
How long is the flight from London?
The flight from London is about 3 h 54 min, so Istanbul is a short-haul option for August warmth. The travel time may appeal if you want a hot-weather city break without committing to a long-haul flight.
About these averages
ERA5-Land climate reanalysis via Open-Meteo (11 km grid) and NOAA Coral Reef Watch 5 km sea temperatures, 1991-2020
Averages computed from daily values at Istanbul. Sea temperature from the nearest 5 km sea cell, 2.5 km from that point. Sunshine hours are estimated from average cloud cover.Records are the highest and lowest daily values in that 30-year period, not all-time records. These are climate averages, not a forecast for your trip. How we measure holiday weather
- Hot · 25°C+
- Warm · 20°C to below 25°C
- Mild · 15°C to below 20°C
- Cool · below 15°C