Email marketing is still a critical channel for today’s marketers, with close to 60% looking to invest more this year. With levels of increased investment, there is also more focus on delivering ROI from email marketing campaigns. This heightened awareness for success, means analysis and optimisation become key to picking up on elements which create the backdrop for more engagement with your emails and, therefore, making your investment work even harder.    

In addition to factors that marketers can influence directly such as offer, content and frequency, there are also numerous contextual factors that can affect the success of your email campaign – the day and time of the send, the frequency, the recipient’s device and, believe it or not, the weather.

Big brands have been capitalising on warmer weather for years. Nuanced data analysis shows clear trends that map out broader marketing precedents. Take Coca Cola, who are well known for ramping up investments in advertising spend when the weather is forecasted to be warmer. In the UK, a country renowned for its unpredictable weather, a seasonal temperature of 1°C higher or lower than average typically leads to a one per cent change in sales, according to data from US-based The Weather Channel, a subsidiary of media conglomerate The Weather Company. In the £300 billion UK retail sector, this would equate to a loss, or gain, of around £3 billion. So evidently, weather conditions along with other contextual factors can have a substantial impact on marketing campaigns and overall sales figures as a whole. 

In this article we consider how weather affects email activity for three household brands – easyJet, Marks & Spencer and McDonald’s, both in the UK and France plus what solutions can be used to elicit the best performance from email optimisation.


Slightly counter-intuitively, warmer average temperatures are shown to increase the effectiveness of easyJet’s email promotions. The mental picture we might have of consumers shivering in the depths of winter and dreaming of summer holidays isn’t entirely correct and easyJet’s UK customers actually appear more pre-disposed to read their emails when the sun is shining.  This trend is even more clearly pronounced for easyJet’s French customers, who demonstrate a major uplift in read rates during warmer, sunnier months. 

Marks & Spencer

Marks & Spencer customers demonstrate a noticeably different set of behaviours. In the UK, there is a slight trend toward higher read rates during both wetter and drier periods. This suggests there is at least some seasonal correlation, perhaps connected with the arrival of new fashion ranges. Again, the behaviour of Marks & Spencer’s French customers is far more clearly pronounced and read rates increase noticeably as it gets wetter (note that France’s Mediterranean climate means many regions have more rain during the summer months). The constant across both regions are that spam complaints are lower when it’s raining and there is a distinct sense that any pre-disposition to respond negatively reduces when customers are stuck inside with nothing better to do!


In the UK, the solar cycle means near-24-hour daylight in the middle of summer and near-permanent twilight during winter. McDonald’s customers align with this cycle, but they are most engaged during the intermediate periods. There is a real sense that when sunshine is in short supply, they are simply less inclined to leave the house, whereas long, sunny evenings inspire them to take to their gardens, parks to socialise with friends and family – not reading emails or visiting fast food chains. Once more, the behaviour of McDonald’s French customers tells another tale. While read rate variances are less clearly defined compared with the other two brands, there is still a pronounced uplift as the days lengthen, so France’s fabled café culture has clearly embraced MacDonald’s too. These trends are corroborated by the user-marked spam metrics – highest in the UK during the sunniest periods and lowest in France.

Overall, there are some interesting differences between UK and French customers. While the former demonstrate some sensitivity to changes in climate change, they are not nearly as pronounced for their French counterparts – who are far more engaged with their emails when the days are long and the mercury is rising.

From our research into how weather effects can influence email marketing, the unexpected nature of the data and differences across geographies show there is a clear benefit to monitoring specific campaign trends as a tool to inform future activity. This research and data-led approach is key to the success of any email marketing campaign. Marketers should look out for email marketing software that integrates analytics into reporting and which can allow users to view relevant analytics reporting results for individual campaigns or data sets. As marketers, you may not be able to control the weather but you can use it to your advantage when ensuring the highest ROI for your email marketing come rain or shine.