Royal Mail issues a warning that deliveries may be late today in parts of Wales and other areas of the UK. The company says the disruption is linked to the current heatwave, which affects parts of its delivery network and operations. WalesOnline reports that some Welsh postcodes could experience delays, attributing the problem to unusually hot conditions. The Mirror reports that 91 UK postcodes are affected, describing the situation as part of the record-breaking heatwave conditions. Together, the reports indicate that Royal Mail is proactively informing customers to expect possible late arrival times for certain addresses. The warnings are presented as temporary operational impacts rather than service cancellations. Customers are encouraged to allow additional time for mail and parcels heading to the affected postcode areas. Royal Mail’s message focuses on the potential for late deliveries and the role of extreme temperatures in causing the disruption.