Aspect & Sun Angle at Different Latitudes

WoSA names altitude, aspect and inclination of the slope as the three most important topographic attributes affecting viticulture, and says topographic effects can be direct, through the incidence of the sun's rays on the earth's surface, or indirect, through soil types and exposure to wind and ventilation. WSET notes that most vineyards are located on at least a gentle slope, that the angle of the slope affects how much sunshine the vines have access to, and that a vineyard facing towards the equator will be warmer and sunnier than one facing away from it. Oregon State University Extension puts it in site-selection terms: slope and aspect determine a site's sunlight exposure patterns and duration, heat accumulation, and air and water drainage.

• Aspect: a vineyard facing towards the equator is warmer and sunnier than one facing away from it (WSET)
• Slope angle: the angle of the slope affects how much sunshine the vines have access to (WSET)
• Three attributes: WoSA names altitude, aspect and inclination of the slope as the most important topographic attributes affecting viticulture
• Site selection: slope and aspect set sunlight exposure, heat accumulation, and air and water drainage (OSU Extension)

WSET places optimal grape-growing conditions generally between 30 and 50 degrees latitude on either side of the equator. The closer a vineyard is to the equator, the warmer it becomes, and cooling influences such as sea breezes or mountain air may be needed to prevent it from getting too hot. Further from the equator the reverse is true, and factors that maximise warmth and sunlight may be necessary to help ripen the grapes. Alongside latitude, WSET says, many other factors affect grape ripening, and the location and aspect of an individual vineyard can make a monumental difference to the final wine. In Germany, Wines of Germany names slopes exposed to the south or south-west in protected valleys as the best prerequisites for viticulture, because the sunshine on the slopes is much more intense than on the plain and south-facing slopes benefit from a longer sunshine duration overall. In the Southern Hemisphere, WoSA notes that northern and western slopes are warmer than southern and eastern ones because they receive more sunlight, and that eastern slopes warm up faster than western slopes and cool earlier.

• Latitude band: optimal conditions are generally found between 30 and 50 degrees either side of the equator (WSET)
• Nearer the equator: cooling influences such as sea breezes or mountain air may be needed (WSET)
• Further from the equator: factors that maximise warmth and sunlight may be needed to ripen the grapes (WSET)
• Southern Hemisphere: northern and western slopes are warmer than southern and eastern ones (WoSA)

Oregon State University Extension's table-grape guide advises choosing a sloping area, especially a south or southwest slope, because it generally has higher temperatures and is less likely to get frost. Slopes also help with frost in another way. WSET notes that cool air tends to tumble down a hill and collect at the bottom, so vineyards on slopes are less affected by frost than those on the valley floor. WoSA says that in the Southern Hemisphere preference is given to the cooler southern and eastern slopes, especially for more delicate varieties like Sauvignon Blanc and Pinot Noir. Soil can magnify the effect of the climate; WSET notes that light-coloured soils reflect sunlight, whereas dark, stony soils store and radiate warmth.

• South or southwest slopes: generally higher temperatures and less likely to get frost (OSU Extension, table grapes)
• Cold-air drainage: cool air collects at the bottom of a hill, so sloped vineyards are less affected by frost than the valley floor (WSET)
• Cooler exposures by choice: in the Southern Hemisphere, southern and eastern slopes are preferred for delicate varieties like Sauvignon Blanc and Pinot Noir (WoSA)
• Soil colour: light soils reflect sunlight; dark, stony soils store and radiate warmth (WSET)

In the Mosel, the Wines of Germany says half of the vineyards are on steep and terraced sites with a slope of over 30 degrees, some planted at a 70-degree gradient, and that the steep slate slopes above the rivers store the sun's heat during the day and release it again at night. A Weinland Mosel brochure explains that, because of the river's meanders, south-facing slopes are found sometimes on the right bank and sometimes on the left, and that thanks to favourable sunlight they offer ideal growing conditions for vines. The Bremmer Calmont, which the Wines of Germany calls the steepest sloped vineyard in all of Europe, has a gradient of up to 60%, and Wines of Germany says the steep slope causes an ideal angle of sun radiation for Riesling. In Burgundy, Bourgogne Wines describes Nuits-Saint-Georges exposures as mostly to the East or South-East, and Meursault's best soils at heights of 260 metres with exposures along an arc between East and South. In the Northern Rhône, Vins Rhône says most of the Hermitage slopes face south and enjoy good sun exposure, on granitic sand with a covering of mica-schists and gneiss. The Barolo DOCG production regulations allow hillside vineyards only, categorically exclude terrain at the bottom of a valley or that is damp, flat or with insufficient exposure to the sun, and exclude new plantings on north-facing slopes from -45° to +45°.

• Mosel: half of the vineyards are on slopes of over 30 degrees, some at a 70-degree gradient; the steep slate slopes store the sun's heat by day and release it at night (Wines of Germany)
• Burgundy: Nuits-Saint-Georges exposures mostly East or South-East; Meursault's best soils face an arc between East and South (Bourgogne Wines)
• Hermitage: most slopes face south; production area of 137 hectares in 2025 (Vins Rhône)
• Barolo: hillsides only, at 170 to 540 metres above sea level, with new plantings on north-facing slopes from -45° to +45° excluded (DOCG regulations)

WoSA explains that changes in altitude create different slopes and aspects, with resulting changes in solar radiation interception, temperature and wind exposure. Altitude also cools: WSET gives a drop of approximately 0.6 degrees Celsius for every 100 metres climbed above sea level, which in warmer climates can provide some relief from the heat. In the Cape, WoSA notes, many farmers have extended their plantings upwards to benefit from better drainage and cooler temperatures, with vineyards located from 50 m above sea level to over 600 m in the mountains. Mountains can also cut sunlight: in the Cape's mountainous terrain, WoSA says some vineyards only see the sun rising as late as 10:00 in the morning, and on the longest day of the year the prime Cape vineyards seldom receive more than 10 hours of sunlight. Soil stores heat as well; the Weinland Mosel brochure notes that one major feature of slate is its ability to store heat, which is particularly advantageous on cool autumn nights.

• Radiation interception: changes in altitude alter slope and aspect, and with them solar radiation interception, temperature and wind exposure (WoSA)
• Altitude: approximately 0.6 degrees Celsius cooler for every 100 metres above sea level (WSET)
• Mountain shade: some Cape vineyards only see the sun rising as late as 10:00 in the morning (WoSA)
• Thermal storage: slate's ability to store heat is particularly advantageous on cool autumn nights (Weinland Mosel)

Barolo's DOCG regulations make aspect a written vineyard requirement: exposure must be appropriate for ensuring suitable ripening of the grapes, and new plantings on north-facing slopes are excluded. In Burgundy, Bourgogne Wines describes the Climats as plots of land for growing vines that have been delimited by winemakers from generation to generation; there are more than a thousand of them, and some were identified as far back as the 7th century. Clos de Vougeot shows how conditions change within one classified site. Founded around 1110 by the monks of nearby Cîteaux, its 50.59 ha have never been broken up, and Bourgogne Wines describes an upper end at about 255 metres that is gently sloping with soil only some 40 cm deep, a centre at about 250 metres with shallow (45 cm), more clayey soil, and a lower portion at around 240 metres with deeper (90 cm) brown soil on a layer of marl rich in clay and alluvium. In the Mosel, the Wines of Germany notes that sundials were installed on sun-drenched southern slopes where grapes for premium wines also flourished, and that many of them gave their names to the surrounding vineyard sites.

• Barolo: aspect is a written requirement, with new plantings on north-facing slopes excluded (DOCG regulations)
• Burgundy: more than a thousand Climats, some identified as far back as the 7th century (Bourgogne Wines)
• Clos de Vougeot: 50.59 ha, of which 49.43 ha under production in 2022; soil depth rises from about 40 cm at the upper end to 90 cm in the lower portion (Bourgogne Wines)
• Mosel sundials: installed on sun-drenched southern slopes; many gave their names to the surrounding vineyard sites (Wines of Germany)

Primary sources: https://www.wsetglobal.com/knowledge-centre/blog/2021/august/24/how-does-geography-affect-a-wine-s-style, https://www.winesofgermany.com/our-wine/viticulture/viticulture/178/soil-sites, https://www.winesofgermany.com/our-regions/growing-area/72/mosel, https://www.winesofgermany.com/our-regions/highlight-of-wine-culture/159/der-calmont, https://www.weinland-mosel.de/media/File/WeinbroschuereMosel2010GB.pdf, https://www.winesofgermany.com/our-regions/highlight-of-wine-culture/361/weinbergs-sonnenuhren, https://www.bourgogne-wines.com/wine-and-terroir/our-natural-assets/climatology/an-ideal-climate-for-producing-great-wines,2483,9268.html, https://www.bourgogne-wines.com/wine-and-terroir/bourgogne-and-its-appellations/nuits-saint-georges,2458,9253.html?args=Y29tcF9pZD0yMjc4JmFjdGlvbj12aWV3RmljaGUmaWQ9MzYxJnw%3D, https://www.bourgogne-wines.com/wine-and-terroir/bourgogne-and-its-appellations/meursault,2458,9253.html?args=Y29tcF9pZD0yMjc4JmFjdGlvbj12aWV3RmljaGUmaWQ9MzQ5Jnw%3D, https://www.bourgogne-wines.com/wine-and-terroir/bourgogne-and-its-appellations/clos-de-vougeot,2458,9253.html?args=Y29tcF9pZD0yMjc4JmFjdGlvbj12aWV3RmljaGUmaWQ9Mjg2Jnw%3D, https://www.vins-rhone.com/en/cotes-du-rhone-cru-aoc-hermitage, https://www.langhevini.it/wp-content/uploads/2019/05/Disciplinare-BAROLO-EN.pdf, https://www.wosa.co.za/The-Industry/Terrior/Topography/, https://extension.oregonstate.edu/catalog/em-8973-establishing-vineyard-oregon-quick-start-resource-guide, https://extension.oregonstate.edu/sites/extd8/files/catalog/auto/EC1639.pdf. Last verified 2026-09-28