I'm sorry, but I couldn't find any specific information regarding a record-setting cold temperature in Dalwhinnie, United Kingdom, during the summer of 1955. Dalwhinnie, located in the Scottish Highlands, experiences cold temperatures throughout the year due to its high elevation and northern latitude. However, extreme cold records can vary depending on specific sources and historical data. It's worth noting that temperature records can be localized and may not always reflect the overall climate or weather patterns of a region. For the most accurate and comprehensive information, it is recommended to refer to official meteorological sources or archives.