As temperatures rise, around a third of customers switch to cold drinks. More than half change their preferred coffee serve between the depths of winter and the height of summer.
We analysed coffee sales at Ensemble in King’s Cross, London, between January and June and found that for every 1°C increase in the daily maximum temperature, cold coffees increased their share of sales by 2.2 percentage points.
For example, during the coldest week of the year, commencing 5 January, the average daily maximum temperature was just 4.9°C, and only 1.6% of coffees sold were cold.
By contrast, during the week commencing 25 May, the average daily maximum reached 29°C, and more than 61% of coffees sold were cold.
As it turns out, people are remarkably predictable. The relationship between daily maximum temperature and the share of coffees served cold is exceptionally strong. Maximum daily temperature alone explains 92% of the variation in cold coffee sales.
We also tested average daily temperature, sunshine hours and total precipitation to see which best predicted customer behaviour. Maximum daily temperature had the strongest statistical relationship. People appear to make their coffee decision based on the warmest part of the day, rather than average conditions or sunshine alone.
Four temperatures every coffee shop should know
This means baristas and managers can confidently plan ahead. Warmer days require more ice, different workflows, and additional glassware and takeaway cups.
In London, several useful tipping points emerge:
- 15°C max temp = 20% cold coffee share
- 20°C max temp = 30% cold coffee share
- 24°C max temp = 40% cold coffee share
- 28°C max temp = over 50% cold coffee share
Changing preferences
We also found that around a third of customers change their regular coffee order across the seasons. Mapping purchases from January to June shows a gradual shift towards less milky and colder coffee serves as temperatures rise.
Most customers’ coffee preferences aren’t fixed; they’re contextual. That’s good news for cafés because the behaviour can be anticipated. By watching the 10-day weather forecast, operators can prepare their teams more effectively, improve service, reduce waste and ensure they have the right products available at the right time.
