Istanbul in May
In May, Istanbul has 37.0 mm (1.46 in) of rain, a daily high of 21.6 °C (70.9 °F) and a daily low of 13.3 °C (55.9 °F), as 1991-2020 model estimates; figures in brackets are converted. The daily high is a model estimate, adjusted against station records.
Last updated : back, with ERA5-Land model estimates.
Best time to visit Istanbul: May meets our rule. Expect 5.0 rain days (model estimate) and days that grow by 56 min.
What May is like in Istanbul
- Redbud blossoms in pink, lilac and purple light up the Bosphorus shore in spring, past Beşiktaş, Kuruçeşme, Yeniköy and Rumeli Hisarı. Source: Go Türkiye (Türkiye Tourism Promotion and Development Agency), checked .
- Wisteria drapes the old lanes of Üsküdar on the Asian shore. It generally blooms April to June, and its scent finds you before you spot the flowers. Source: Daily Sabah, checked .
- Arnavutköy used to be known for its small Ottoman strawberries, less juicy than other kinds. Each spring, strawberry lovers crowd the local greengrocers. Source: Wikipedia, checked .
Key figures
Weather in May, 1991-2020 model estimates
- Daily high
- 21.6 °C (70.9 °F)
- Daily low
- 13.3 °C (55.9 °F)
- Rain
- 37.0 mm (1.46 in) in the month
- Sunshine
- no data
Model estimate 1991-2020, not a weather station: ERA5-Land model estimates (Copernicus), computed by City by Month for the grid cell nearest the city. Daily high and Days with rain: model estimate, adjusted against station records. Licence: CC BY 4.0. Checked . How we make and test model estimates
Model estimate for the ERA5-Land grid cell at 41.0° N, 29.0° E, 4 km from the city centre point.
How we define and convert these figures
Notes. Sunshine: Not in our ERA5-Land estimates.
Daylight on 15 May 2026
- Sunrise
- 05:47 local time
- Sunset
- 20:15 local time
- Day length
- 14 h 29 min
Day length 1-31 May: 13 h 58 min to 14 h 54 min, +56 min.
Source: NOAA Solar Calculator equations, checked .
Month by month
Each month: daily high in °C, then rain in mm, 1991-2020 model estimates.
ERA5-Land model estimates 1991-2020, as above, checked .
This month against the year
| Measure | May | Rank |
|---|---|---|
| Daily high | 21.6 °C | 5th warmest |
| Daily low | 13.3 °C | 6th warmest |
| Rain | 37.0 mm | 4th driest |
| Sunshine | no data | no data |
| Day length | 14 h 29 min | 3rd longest |
Equal values share a rank. How we rank months
Istanbul in May, on average: 5.0 rain days (1 mm or more). Model estimate, adjusted against station records.
ERA5-Land model estimates 1991-2020, as above, checked .
Day length: NOAA solar equations, checked .
Public holidays this month
| Date | Holiday |
|---|---|
| Friday | Labour and Solidarity Day |
| Tuesday | Commemoration of Atatürk, Youth and Sports Day |
| Tuesday | Eid al-Adha (from 1pm) |
| Wednesday | Eid al-Adha (Day 1) |
| Thursday | Eid al-Adha (Day 2) |
| Friday | Eid al-Adha (Day 3) |
| Saturday | Eid al-Adha (Day 4) |
| Date | Holiday |
|---|---|
| Saturday | Labour and Solidarity Day |
| Saturday | Eid al-Adha (from 1pm) |
| Sunday | Eid al-Adha (Day 1) |
| Monday | Eid al-Adha (Day 2) |
| Tuesday | Eid al-Adha (Day 3) |
| Wednesday | Eid al-Adha (Day 4) |
| Wednesday | Commemoration of Atatürk, Youth and Sports Day |
Typed from the official lists for 2026 and 2027 and re-checked, .
English names are from the holidays library where the official list gives none. How we check holidays
Source: Official public holiday list (vakithesaplama.diyanet.gov.tr) for 2026 and 2027, checked ; holidays Python library, checked . Library: holidays 0.105.
Same month in 8 model-estimate cities
Istanbul is warmer than 2 of our 8 model-estimate cities in May by mean daily high. How we rank cities
Closest high and low in May: Porto (0.6 °C apart), Sydney (0.8), Lisbon (1.2).
| City | Gap from Istanbul, °C | High, °C | Low, °C | Rain, mm | Sunshine, hours |
|---|---|---|---|---|---|
| Istanbul (this page) | — | 21.6 | 13.3 | 37.0 | no data |
| Porto (closest) | 0.6 | 21.8 | 12.4 | 98.1 | no data |
| Sydney (closest) | 0.8 | 20.7 | 12.7 | 72.7 | no data |
| Lisbon (closest) | 1.2 | 22.5 | 14.7 | 45.1 | no data |
| Melbourne | 4.2 | 17.6 | 9.0 | 50.5 | no data |
| Mumbai | 12.8 | 34.0 | 26.5 | no data | no data |
| Bangkok | 13.3 | 34.7 | 26.7 | no data | no data |
| Delhi | 15.9 | 41.2 | 25.4 | no data | no data |
Sources (1991-2020): ERA5-Land model estimates, checked . Each city's page names its grid cell. All sources in full on Methodology.
Sources
- Attribution: Copernicus Climate Change Service (2025): ERA5 Land hourly time-series data from 1950 to present. Copernicus Climate Change Service (C3S) Climate Data Store (CDS). DOI: 10.24381/ee82e357. Accessed on the check date shown. Generated using or contains modified Copernicus Climate Change Service information 2025. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains. Licence: CC BY 4.0. Checked .
- NOAA Solar Calculator equations, computed locally, NOAA Global Monitoring Laboratory (method); City by Month (computation). Attribution: Computed with the NOAA Solar Calculator method (no NOAA endorsement implied). Licence: Method, not data. Checked .
- holidays Python library, run locally. Attribution: holidays library, Vacanza team. Licence: MIT. Checked .
Official sources
Cite this page: City by Month. "Istanbul in May: weather, daylight, holidays". https://citybymonth.com/cities/turkey/istanbul/may/. Last updated 8 November 2026.