Cool places in hot regions
Every warm wine region has a corner that stays cool. I mapped eight of them against a warm neighbour, to show what keeps them fresh: height, mountains, the sea or simply being further south.
A region's name tells you less than it seems. Sicily, the Languedoc and Mendoza all suggest warm, ripe wine, and much of what they make is exactly that. But each has a place where the vines sit higher, closer to the mountains or nearer cold water, and the wine from there is a different thing: more acidity, lower alcohol, more tension. As summers warm, these are the places I find myself buying again.
For each pair, I took 30 growing seasons, 1994 to 2023, from the ERA5-Land climate record: April to October in the northern hemisphere, October to April in the southern hemisphere. The maps show the average growing-season temperature on the same colour scale throughout, so a colour means the same temperature on every map.
How to read the maps
Grey-blue is sea; lakes such as Garda are part of the land grid, so they are labelled but not drawn. The thin lines are height contours, labelled in metres. The blue marker is the cool site, the red marker its warm neighbour, and the labels in the map name the mountains, seas and winds that make the difference.
The climate record comes in cells about 9 km across, too coarse to show a valley or a slope. So the maps combine it with a terrain model with detail down to about 150 m. Each cell's temperature is brought to sea level using the standard rate at which air cools with height, 6.5°C per 1,000 m, blended smoothly between cells, then brought back up to the height of every point on the map. Valleys come out warm and slopes cool, as they are. What this cannot add is anything smaller than a cell that does not follow height, such as a single foggy hollow or a sea breeze reaching a few kilometres inland.
The tables use the same idea. Each cell's height is an average, and where the cell takes in mountainside it sits well above the vines: the Etna cell averages 1,141 m, while the vines are around 700 m. So every table temperature is brought to the vineyards' typical height.
1Limoux: height and Atlantic air
Limoux and the Languedoc
Average growing-season temperature (Apr to Oct, 1994 to 2023) adjusted to the terrain, with height contours.
Limoux sits on the edge of the Languedoc, one of the warmest wine regions in France, yet it has made sparkling wine for centuries. The Haute Vallée is its highest and coolest corner, in the foothills of the Pyrenees.
Two things keep it fresh. Height, and Atlantic air that reaches it from the west through the gap between the Pyrenees and the Montagne Noire, rather than the warm Mediterranean air that bathes the Corbières plain.
| Haute Vallée | Corbières | |
|---|---|---|
| Vineyard height | 300–500 m | 50–150 m |
| Season average | 15.5°C | 18.7°C |
| Average daily high | 19.9°C | 23.3°C |
| Average night, harvest month | 12.0°C | 15.2°C |
| Rain in the season | 684 mm | 376 mm |
| Warming per decade | +0.64°C | +0.65°C |
3.2°C cooler over the growing season, at the vineyards' height. At its current rate of warming, Haute Vallée would reach where Corbières is today in about 50 years.
2Alto Adige: the Alps above the Veneto
Alto Adige and the Veneto
Average growing-season temperature (Apr to Oct, 1994 to 2023) adjusted to the terrain, with height contours.
Alto Adige is a narrow valley cut through the Alps, and the vineyards climb its sides. Valpolicella, 100 km south, sits on the edge of the hot Po plain, warmed further by Lake Garda.
The valley floor around Bolzano can be very hot in summer, so in Alto Adige the grower's choice of slope and height does a lot of the work. Mountain air flowing down the valleys at night cools the vines.
| Kaltern | Valpolicella | |
|---|---|---|
| Vineyard height | 250–600 m | 150–450 m |
| Season average | 17.0°C | 18.1°C |
| Average daily high | 21.2°C | 22.1°C |
| Average night, harvest month | 12.5°C | 14.8°C |
| Rain in the season | 758 mm | 668 mm |
| Warming per decade | +0.53°C | +0.52°C |
1.1°C cooler over the growing season, at the vineyards' height. At its current rate of warming, Kaltern would reach where Valpolicella is today in about 20 years.
3Etna: a mountain in the Mediterranean
Etna and southern Sicily
Average growing-season temperature (Apr to Oct, 1994 to 2023) adjusted to the terrain, with height contours.
Sicily is about as far south as Europe's classic vineyards go. Vittoria, in the south-east, makes warm, generous Frappato and Nero d'Avola close to the sea.
Etna is the exception. Its vines climb the volcano's slopes to around 1,000 m. Over the whole season the gain is modest once the data is brought to vineyard height, but the nights are where it shows: cooler nights in the run-up to harvest, which on Etna often runs into October, help keep Nerello Mascalese and Carricante fresh.
| Etna north slope | Vittoria | |
|---|---|---|
| Vineyard height | 600–800 m | 150–250 m |
| Season average | 20.0°C | 21.0°C |
| Average daily high | 24.2°C | 23.9°C |
| Average night, harvest month | 17.8°C | 19.8°C |
| Rain in the season | 514 mm | 163 mm |
| Warming per decade | +0.41°C | +0.50°C |
0.9°C cooler over the growing season, at the vineyards' height. At its current rate of warming, Etna north slope would reach where Vittoria is today in about 25 years.
4Mendoza: the Uco Valley against the plains
Mendoza: the Uco Valley and the east
Average growing-season temperature (Oct to Apr, 1994 to 2023) adjusted to the terrain, with height contours.
Mendoza is a desert. Eastern Mendoza, on the lower plains, makes most of Argentina's wine, much of it warm and generous.
The Uco Valley sits right under the Andes, with vineyards up to around 1,500 m. Cold air drains off the mountains at night, and the gap between day and night is large, which is what keeps Malbec from Gualtallary or Tupungato fresher and more structured.
| Uco Valley | East Mendoza | |
|---|---|---|
| Vineyard height | 900–1,500 m | 600–750 m |
| Season average | 15.0°C | 22.0°C |
| Average daily high | 21.0°C | 28.1°C |
| Average night, harvest month | 8.9°C | 16.1°C |
| Rain in the season | 650 mm | 313 mm |
| Warming per decade | +0.53°C | +0.59°C |
7.0°C cooler over the growing season, at the vineyards' height. At its current rate of warming, Uco Valley would reach where East Mendoza is today in about 130 years.
5Elgin: cooled by the sea
Elgin and Stellenbosch
Average growing-season temperature (Oct to Apr, 1994 to 2023) adjusted to the terrain, with height contours.
Elgin is the one place in this piece where height is not the main story: its vineyards are at much the same height as Stellenbosch's.
It is the sea. Elgin sits on a plateau a few kilometres from the cold water of False Bay, and the summer south-easterly wind brings cloud and cool air in off the sea. The difference is in the afternoons: Elgin's days are cooler, and it averages about 11 days a season at 30°C or more against 37 in Stellenbosch. It makes some of South Africa's best Chardonnay, Sauvignon Blanc and Pinot Noir, while Stellenbosch, a short drive away, is Cabernet country.
| Elgin | Stellenbosch | |
|---|---|---|
| Vineyard height | 200–450 m | 100–400 m |
| Season average | 18.3°C | 19.3°C |
| Average daily high | 23.1°C | 25.3°C |
| Average night, harvest month | 15.4°C | 15.4°C |
| Rain in the season | 273 mm | 258 mm |
| Warming per decade | +0.18°C | +0.23°C |
1.1°C cooler over the growing season, at the vineyards' height. At its current rate of warming, Elgin would reach where Stellenbosch is today in about 60 years.
6Hemel-en-Aarde: the ocean against the Breede
Hemel-en-Aarde and Robertson
Average growing-season temperature (Oct to Apr, 1994 to 2023) adjusted to the terrain, with height contours.
Robertson, in the Breede River valley behind the mountains, is warm, dry country, where the vines depend on the river for water.
Hemel-en-Aarde, “heaven and earth”, runs inland from Walker Bay near Hermanus, a few kilometres from the cold ocean. Sea air keeps its afternoons cool: about 8 days a season reach 30°C, against 65 in Robertson. It is Pinot Noir and Chardonnay country, and makes some of South Africa's most Burgundian wine.
| Hemel-en-Aarde | Robertson | |
|---|---|---|
| Vineyard height | 100–400 m | 150–250 m |
| Season average | 17.9°C | 20.6°C |
| Average daily high | 22.1°C | 27.8°C |
| Average night, harvest month | 15.5°C | 15.8°C |
| Rain in the season | 237 mm | 232 mm |
| Warming per decade | +0.19°C | +0.20°C |
2.7°C cooler over the growing season, at the vineyards' height. At its current rate of warming, Hemel-en-Aarde would reach where Robertson is today in about 140 years.
7Sta. Rita Hills: a valley open to the Pacific
Santa Barbara County
Average growing-season temperature (Apr to Oct, 1994 to 2023) adjusted to the terrain, with height contours.
Most of California's coast is walled off by mountains running north to south. In Santa Barbara County they run east to west, so the valleys open straight onto the cold Pacific, and fog and wind pour inland most afternoons.
The Sta. Rita Hills, at the ocean end of the Santa Ynez Valley, make Pinot Noir and Chardonnay, with average afternoon highs of about 19.8°C. Happy Canyon, some 40 km inland at the other end of the same valley, reaches 23.8°C and is warm enough for Cabernet. The Santa Maria Valley to the north, also open to the ocean, is just as cool.
| Sta. Rita Hills | Happy Canyon | |
|---|---|---|
| Vineyard height | 60–300 m | 200–450 m |
| Season average | 16.3°C | 19.4°C |
| Average daily high | 20.1°C | 24.2°C |
| Average night, harvest month | 15.2°C | 17.0°C |
| Rain in the season | 55 mm | 66 mm |
| Warming per decade | +0.21°C | +0.25°C |
3.1°C cooler over the growing season, at the vineyards' height. At its current rate of warming, Sta. Rita Hills would reach where Happy Canyon is today in about 145 years.
8Tasmania: the cool end of Australia
South-eastern Australia
Average growing-season temperature (Oct to Apr, 1994 to 2023) adjusted to the terrain, with height contours.
The Barossa is Australia's warm heartland, home of rich, ripe Shiraz. When Australian winemakers want somewhere cool, more and more of them look south, across Bass Strait.
Tasmania is the exception in this piece: not a cool corner next door but an island about 1,000 km south. Its coolness comes from latitude and the Southern Ocean all around it, and it has become Australia's source of fine sparkling wine, Pinot Noir and Chardonnay.
| Tamar Valley | Barossa | |
|---|---|---|
| Vineyard height | 20–200 m | 230–400 m |
| Season average | 14.2°C | 18.5°C |
| Average daily high | 19.3°C | 24.6°C |
| Average night, harvest month | 10.2°C | 13.5°C |
| Rain in the season | 434 mm | 198 mm |
| Warming per decade | +0.39°C | +0.38°C |
4.3°C cooler over the growing season, at the vineyards' height. At its current rate of warming, Tamar Valley would reach where Barossa is today in about 110 years.
What it means if you are buying
- Look past the region to the site. “Sicily” or “Mendoza” on a label tells you little. Etna, the Uco Valley or Elgin tell you a lot more about how fresh the wine will be.
- Big height differences make big gaps. The Uco Valley, several hundred metres above eastern Mendoza and right under the Andes, is 7.0°C cooler. Where the heights are closer, as in Alto Adige, on Etna and in Elgin, the season averages differ by about a degree, and the difference shows in the nights or the afternoons rather than across the whole season.
- Cold water works too. Elgin, Hemel-en-Aarde and the Sta. Rita Hills show that a cold sea nearby can take the edge off the hottest afternoons, much as a mountain does.
- Or go south. Tasmania, about 1,000 km south of the Barossa, is 4.3°C cooler through the season, with no mountain needed.
- The cool places are warming as well. The ten places here have warmed by about 0.40°C a decade on average since 1995. At that pace, a one-degree advantage lasts about two decades: Kaltern would reach where Valpolicella is today in about 20 years, the Uco Valley in more than a century.
What it doesn't show
- The terrain sharpens the maps, not the record. The temperatures still come from 9 km cells; the finer detail follows height alone. Sea breezes, fog and cold air pooling at smaller scales are not in it, and the height adjustment in the tables is an estimate based on typical vineyard heights, not a measurement at any one vineyard.
- Temperature is not everything. Wind, fog, soil, sunlight and the grower's choices all shape the wine. The maps show one strong influence, not all of them.
- The sea, lakes and winds are labelled, not measured. The labels point to the factors that explain the pattern; the record shows the temperatures, not the airflow itself.
Conclusion
The warmest regions all have places where wine stays fresher, and the climate record shows it: in every pair the cool site is cooler through the season, by 0.9 to 7.0°C at the vineyards' height. Some gaps are large and will last generations, others are a degree that a couple of decades of warming will use up. As summers warm, those places matter more, and I expect more of the wines I buy again to come from them: the high slopes, the valleys under the mountains, the plateaus by cold water. It also fits what I found in Do hot vintages really taste riper?: heat shows in the glass, and the places that escape it are worth knowing.
Climate: ERA5-Land reanalysis (Copernicus Climate Change Service), monthly mean 2 m temperature on a 0.1° grid for the maps, and hourly 2 m temperature and rainfall at each site's cell for the tables, 1994 to 2023; warming per decade is a linear trend over 1995 to 2025. Terrain: Mapzen Terrarium elevation tiles (AWS Open Data, built from SRTM, GMTED and other sources), about 150 m detail (about 1 km for the Australia map); map temperatures are each cell's 1994 to 2023 average brought to sea level with the ERA5-Land cell height, interpolated between cells, then raised to the terrain height at 6.5°C per 1,000 m. Cell heights: ERA5-Land surface geopotential. Vineyard heights are approximate typical ranges; table temperatures are moved from the cell's average height to the middle of that range at 6.5°C per 1,000 m. Harvest month: September in the northern hemisphere, March in the southern hemisphere.