According to Steele (1951) and Murray et al. (2010) four theories can be defined regarding the nature of weather effects on retail sales. According to the first theory, weather can create such conditions that consumers feel uncomfortable to leave their homes and go to the store. Cold temperatures and precipitation my hinder travel, keeping consumers away from stores. The results of a survey conducted among consumers show that snow acts as the strongest disincentive on consumers – 45% of respondents state they will not go shopping when snowing, 37% of respondents will not go shopping when raining, 35% will not go shopping in severe cold and 30% will not go shopping in excessive heat (Kirk, 2005). Starr-McCluer (2000) calls such impact of weather “the convenience effect” and states that excessive cold and heavy rain reduce sales of products purchase of which is easily deferrable, such as furniture and apparel. Moreover, research shows that rain has negative impact on shopping centre attendance (Parsons, 2001).
According to the second theory, weather can physically prevent consumers from going shopping. For example, heavy snowfall can result in such effects. Because certain weather hampers traffic mobility, the occurrence of adverse weather will not have the same impact on all stores but the impact will depend on the location of the store (Agnew and Thornes, 1995; Ryski, 2011). Poor weather can have adverse effect on the number of shoppers in large format food stores (supermarkets and hypermarkets) located on the edges of urban areas and, on the contrary, favorable effect on the small neighborhood stores (Agnew and Thornes, 1995).
The third theory suggests that weather has a psychological effect on consumers that causes changes in their shopping behavior. It is known that low levels of humidity, high levels of sunlight, high pressure and high temperature are associated with good mood and that people in positive mood are more likely to self-reward and to spend more money. Results of Murray et al. (2010) confirm that sunlight has positive effect on consumer spending, whereas Sun et al. (2009) found that bad weather characterized by low temperatures, decreasing sunlight and increasing precipitation has favorable effect on negative hedonic consumption (consumption of alcohol and cigarettes).
The forth theory suggests that weather does not affect the sale of all product categories in the same way but the impact depends on the special characteristics of the product category. Certain weather can have positive effect on sale of one group of products and simultaneously negative or neutral effect on other group of products. For example, temperature has positive effect on sales of ice creams and soft drinks, rainfall has positive effect on sales of umbrellas and raincoats, snow and frost have positive effect on sale of salt for gritting roads, etc. Thus it is incorrect to make deductive conclusions about weather sensitivity of certain types of stores (Starr-McCluer, 2000) or certain categories of products (Agnew and Thornes, 1995; Agnew and Palutikof, 1999) based on the weather sensitivity of the total national retail sales or total store sales.
The sales of weather sensitive products oscillate during the year depending on the season and weather. For example, food and drink products are largely purchased in the summer, whereas clothing products largely in the winter (Roslow et al., 2000). Parsons (2001) argues that the seasonal effect on sales is manifested as the product-based influence (e.g., sunscreen sales in the summer, heaters sale in the winter) and as the weather-based influence (if low temperatures enhance sales, the effect of weather will be stronger in winter because it is colder in winter). Results of empirical studies show that a large number of products entail seasonality in sales, such as soft drinks (Agnew and Thornes, 1995; Blom, 2009); beer (Silm and Ahas, 2004); clothing (Bahng and Kincade, 2012); car batteries (Kirk, 2005); herbs, vegetables and flowering annual plants (Behe et al., 2012) and building materials (Starr-McCluer, 2000). As the main causes of seasonality authors state weather and holidays.