The Complete Guide to European Climate Zones for Gardeners

A plant label tells you how much frost a plant survives. It does not tell you how long your season is, how hot your summer gets or when the rain falls. A Köppen climate code does. The codes you see across this blog – Cfb, Dfb, Cfa, Csa – all come from that system.

The map behind those codes has moved. Prague, Berlin and Vienna were continental Dfb on the 1961–1990 map. On the 1991–2020 map all three are oceanic Cfb.

Why a hardiness zone is not enough

Plant labels and catalogues often quote a USDA zone, the hardiness scale of the US Department of Agriculture. That number measures one thing. The USDA map is based on the average annual extreme minimum winter temperature, split into 10 °F bands from zone 1 to zone 13. In plain words, it records how cold the coldest night of an average winter gets.

The USDA says as much itself. Its guidance lists wind, soil moisture, humidity and snow among the things that decide whether a plant survives. It calls summer heat and moisture balance "particularly important".

Britain's Royal Horticultural Society (RHS) uses a similar scale. Its nine hardiness ratings run from H1a to H7 and give the lowest temperature a plant is likely to withstand:

Both scales answer one question: will this plant survive my coldest night? Neither tells you whether your summer is warm enough to ripen a pepper, or whether July brings rain or drought. A climate zone does. Use the two together. The Köppen zone plans your season, and the hardiness rating picks plants that survive your winter.

How to read a Köppen code

The Köppen-Geiger classification sorts climates by monthly temperature and rainfall. It has five major classes and 30 sub-classes, and each code is two or three letters long. These are the letters a European gardener meets, with the thresholds used for the current world maps:

So Cfb reads as temperate, no dry season, warm summer. Dfb has the same summer, but its coldest month averages 0 °C or lower. Csa is temperate with a dry, hot summer.

The arid codes use their own letters. BSk is cold steppe and BSh is hot steppe, split at a mean annual temperature of 18 °C.

One detail explains most disagreements between maps. The current maps draw the line between C and D at a coldest month of 0 °C. Other sources draw it at −3 °C. A town whose coldest month averages −1 °C is Dfb by the first rule and Cfb by the second. Warsaw is a good example. It is listed as Cfb or Dfb depending on which line is used.

Where European cities sit on the 1991–2020 map

We took the 1 km Köppen-Geiger map for 1991–2020 published by Beck and colleagues and read the class at each city centre. A garden higher up or in a cold valley can fall into the next class, so treat the table as a starting point.

A few cities straddle a boundary inside the city itself. Bratislava and Innsbruck are Cfb at the centre with Dfb within about two kilometres. Wrocław is Dfb at the centre with Cfb around it. Ljubljana mixes Cfa and Cfb, and Lisbon mixes Csa and Csb.

What changed since 1961–1990

The same dataset holds a map for 1961–1990. These are the main moves among the cities in the table:

• Dfb to Cfb: Berlin, Leipzig, Dresden, Nuremberg, Munich, Copenhagen, Malmö, Gothenburg, Prague, Vienna, Linz, Trnava and Szczecin.
• Dfb to Dfa: Budapest, Debrecen, Chișinău and Odesa.
• Dfb to Cfa: Belgrade, Novi Sad, Szeged, Pécs, Győr, Komárno and Timișoara.
• Cfb to Cfa: Lyon, Toulouse and Zagreb.
• Cfa to Csa: Florence, Bari and Tirana.
• Into the steppe classes: Madrid moved from Csa to BSk. Valencia and Alicante moved from BSk to BSh.

The authors estimate that about 5% of the world's land outside Antarctica moved to a different major class between 1901–1930 and 1991–2020. Older maps and books still file Prague and Berlin under Dfb, as an earlier version of this guide did.

The codes are built from monthly averages. They say nothing about the single coldest night of the winter. A move from Dfb to Cfb is no reason to plant less hardy shrubs.

When another source shows a different code

The city pages on climate-data.org list Warsaw as Cfb and Budapest as Cfa. The 1991–2020 map has them as Dfb and Dfa. Sources can differ in the years they average and in where they draw the line between C and D. When two sources disagree about your town, you garden near a boundary.

What each zone means in your garden

Many of our guides split their advice into three zones: Atlantic (Cfb), Continental (Dfb) and Mediterranean (Csa). The first letter of your code describes your winter. As a rule of thumb, follow the Atlantic advice with a C code other than Csa or Csb. With a D code, follow the Continental advice.

Cfb – oceanic

The coldest month stays above 0 °C, the warmest stays below 22 °C, and no season is dry.

• Check drainage first. Lavender needs fast-draining soil. The RHS warns that it will not thrive in heavy clay or in any soil that becomes waterlogged. On heavy soil, plant it on a 20–30 cm mound or in a raised bed. Rosemary also hates wet roots, especially in winter.
• Give heat lovers your warmest spot. Outdoors, tomatoes need a warm, sunny, sheltered site. Sweet peppers are usually grown under cover in the UK.
• Expect blight in damp summers. Tomato blight is most common in warm, wet weather. The RHS calls it a very serious disease on outdoor tomatoes and says greenhouse plants are less likely to be affected.

Dfb – humid continental

The summer matches Cfb. The difference is winter, when the coldest month averages 0 °C or lower.

• Wait for the last frost. Central European gardeners time tender plants by the Ice Saints. Germany's weather service, the DWD, puts them at 11–15 May. It notes that cold air in those days can still bring frost anywhere in Central Europe. In Poland, the Czech Republic and Slovakia the Ice Saints fall on 12–14 May, followed by St Sophia on 15 May. Our late frost guide covers what to do when a cold night is forecast.
• Buy for the winter you get. The RHS describes H6 plants (−20 to −15 °C) as hardy throughout the UK and northern Europe. H7 plants are hardy in the severest European continental climates.
• Keep borderline plants mobile. Well-established rosemary survives down to −8 °C. In cooler regions the RHS suggests keeping figs in a pot, so they can be moved indoors over winter.
• Stay out of frost pockets. Cold air flows downhill and collects at the lowest point or against a barrier. The RHS advice on frost damage is to choose planting positions that avoid those spots.
• Cover the soil. A mulch at least 5 cm thick protects roots in winter and helps the soil hold moisture in summer.

Cfa and Dfa – hot summers with rain

The warmest month averages 22 °C or more, and there is no dry season. Cfa keeps its coldest month above 0 °C. In Dfa it averages 0 °C or lower.

• Grow heat lovers in the open. Sweet peppers need lots of sun and consistent warmth. In the UK the RHS finds them only really successful outdoors in milder areas or in long, hot summers. A hot summer is what the letter "a" stands for.
• Water deeply, not often. The RHS rule for watering is less often but more thoroughly, until the soil is moist 15 cm down.
• In Dfa, treat winter as Dfb. The hardiness, frost-pocket and mulch rules above all apply.

Csa and Csb – Mediterranean

Summer is the dry season. The driest summer month brings under 40 mm of rain, and less than a third of the wettest winter month. Csa adds a hot summer and Csb a warm one. In our table, Csb is the Atlantic north-west of Iberia: Porto, Vigo, Santiago de Compostela and A Coruña.

• Plant for drought. Many drought-tolerant plants have silver or grey-green leaves. Lavender thrives in full sun and is drought tolerant, and so is rosemary.
• Plant small. The RHS guide to drought-resistant gardening recommends buying perennials in 9 cm pots, because young plants establish more quickly. Water down to the root zone after planting.
• Cover the soil here too. Use the same 5 cm mulch as in Dfb. Here its job is to keep moisture in the soil through summer.
• Use the cool season. Our November guide gives Csa the whole month for garlic, overwintering onion sets and hardy broad beans.

BSk and BSh – semi-arid

Madrid and Zaragoza are BSk. Valencia, Alicante and Murcia are BSh. Yearly rainfall stays below the arid limit, so the drought advice in the Mediterranean list matters even more here.

Dfc, Cfc and ET – short summers

Dfc has only one to three months that average above 10 °C. On the map that covers Rovaniemi, Oulu, Kiruna and Tromsø. It also covers high alpine resorts such as Davos, Zermatt and St. Moritz, and Štrbské Pleso in the High Tatras. In ET, the tundra class, even the warmest month averages 10 °C or lower. Reykjavík is Cfc, the cold-summer form of the oceanic climate.

Some places you might expect here sit elsewhere on the map. Stockholm, Oslo and Helsinki are Dfb. Inverness and Aviemore in the Scottish Highlands are Cfb.

• Choose the hardiest rating. H7 is the RHS rating for the severest European continental climates.
• Pick quick crops. With so few warm months, start with our list of fast-growing vegetables.

How to use your zone in three steps

1. Find your code. Start with the table above. For other towns, the city pages on climate-data.org state the Köppen-Geiger class. If two sources disagree, plan for the colder one.
2. Add the hardiness rating. The zone plans your season. The RHS rating or USDA zone on the label tells you whether the plant survives your coldest night.
3. Read your own plot. Cold air collects in frost pockets, and the RHS notes that tender plants survive winter better in a sheltered, sunny position. Altitude counts too: Poprad is Dfb, and Štrbské Pleso above it is Dfc.

Common mistakes

• Reading a hardiness zone as a climate zone. Zone 7 on a label is about winter nights. It says nothing about summer heat or rain.
• Trusting an old map. Thirteen of the cities in our table moved from Dfb to Cfb between the 1961–1990 and 1991–2020 maps.
• Reading the code as a frost date. The code is an average. The DWD still expects frost to be possible in mid-May.
• Planting Mediterranean herbs in wet soil. Lavender will not thrive in waterlogged ground, and rosemary hates wet roots in winter.

Sources and tools

• Köppen-Geiger maps: Beck et al. (2023), Scientific Data 10, 724. The maps for 1901–2099 are free to download at gloh2o.org/koppen.
• Hardiness: the USDA guide to its zone map and the RHS hardiness ratings.
• City lookup: climate-data.org.
• Plant search: the Plantory encyclopedia can be filtered by USDA hardiness zone, sun and water needs.

This guide was revised on 9 October 2026. The city lists and thresholds now follow the 1991–2020 map. The earlier version listed Prague, Berlin and Vienna as Dfb and filed the Mediterranean cities under Csb.

Plan with both numbers

A Köppen code describes your average year. A hardiness rating describes its coldest night. Plan with both, and check your code against the current map rather than the one in an old book.

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