Heat in Brno by neighbourhood
On a hot day the gap between a baking street and a shady neighbourhood full of trees can be bigger than you would expect. Where Brno overheats in summer, where it stays cool and what to look for in a flat.
What a heat island is
A city warms up more than the countryside around it in summer: roofs, asphalt and concrete soak up the sun during the day and give the heat back slowly at night. This is called the urban heat island. You feel it most at night, when the hot streets don’t have time to cool down and it is hard to sleep in a flat. Trees, lawns and water do the opposite: they give shade and cool the air by evaporating water.
Which neighbourhoods overheat and which don’t
We compare the surface temperature on summer days from Landsat satellite images, as the difference from the city average, for 36 neighbourhoods. The coolest surface is in Soběšice (-7.4 °C), Bystrc (-5.9 °C) and Jundrov (-5.5 °C). The ones that overheat most are Zábrdovice (+4.5 °C), Trnitá (+4.4 °C) and Brno-město (+3.8 °C).
Brno’s coolest neighbourhoods in summer
- -7.4 °C against the city average Soběšice Brno-sever
- -5.9 °C against the city average Bystrc Brno-Bystrc
- -5.5 °C against the city average Jundrov Brno-Jundrov
- -4.2 °C against the city average Žebětín Brno-Žebětín
- -3.2 °C against the city average Obřany Brno-Maloměřice a Obřany
- -3.2 °C against the city average Řečkovice Brno-Řečkovice a Mokrá Hora
- -3.1 °C against the city average Kohoutovice Brno-Kohoutovice
- -3.0 °C against the city average Pisárky Brno-střed
- -2.4 °C against the city average Bosonohy Brno-Bosonohy
- -1.6 °C against the city average Komín Brno-Komín
This is the temperature of the surface (roofs, streets, lawns) at the moment of the image, not the air temperature. It still shows the differences between neighbourhoods well: where the surface is warmer, the air and above all the nights tend to be warmer too.
Trees cool the most
The largest share of land under tree and shrub canopy is in Jundrov (77 %), Soběšice (74 %) and Bystrc (73 %). A tree in front of a building shades the façade and the pavement and can cool a street noticeably in summer, so look at the greenery in the street itself, not just at a park a few blocks away.
Brno’s neighbourhoods with the most trees
- 77 % of the area under trees Jundrov Brno-Jundrov
- 74 % of the area under trees Soběšice Brno-sever
- 73 % of the area under trees Bystrc Brno-Bystrc
- 57 % of the area under trees Pisárky Brno-střed
- 55 % of the area under trees Žebětín Brno-Žebětín
- 54 % of the area under trees Kohoutovice Brno-Kohoutovice
- 53 % of the area under trees Obřany Brno-Maloměřice a Obřany
- 52 % of the area under trees Řečkovice Brno-Řečkovice a Mokrá Hora
- 40 % of the area under trees Medlánky Brno-Medlánky
- 39 % of the area under trees Nový Lískovec Brno-Nový Lískovec
What to look for in a flat
- Floor: a flat under a flat roof without insulation gets the hottest in summer. Attic and top-floor flats need a well-insulated roof.
- Windows: south- and especially west-facing windows catch the afternoon sun. Ask whether external blinds or shutters can be fitted: shading outside works much better than inside.
- Ventilation: a flat with windows on two sides of the building can be aired by a through draught at night. The courtyard side tends to be quieter and often cooler.
- Surroundings: trees in the street, a park or water nearby do more than the neighbours’ air conditioning. A hot car park or a large area of roofs under the windows gives the heat back at night.
- An older brick building with thick walls stays cool longer than a light structure; in new builds, ask about shading and heat-recovery ventilation.
Frequently asked questions
Where is it coolest in Brno in summer?
According to satellite images, the coolest summer surface is in Soběšice (-7.4 °C against the city average), Bystrc (-5.9 °C) and Jundrov (-5.5 °C). Trees, woods and water do most of the cooling.
Which part of Brno overheats the most in summer?
The warmest surface is in Zábrdovice (+4.5 °C against the city average), Trnitá (+4.4 °C) and Brno-město (+3.8 °C). What overheats are mainly roofs, asphalt and concrete without shade.
Where are the most trees in Brno?
The largest share of land under tree and shrub canopy is in Jundrov (77 %), Soběšice (74 %) and Bystrc (73 %), based on the satellite land cover map.
