summer greeting card; midsummer inquiry after someone's health
A seasonal greeting sent during the hottest part of summer (typically from early July to early August) to inquire after someone's health. Often a postcard, but can also refer to the act of sending such greetings.
See also: 暑中お見舞い
This year too, I sent summer greeting cards to those who have helped me.
The period for sending midsummer greetings is until the start of autumn (around August 7th).
I sent my grandmother a summer greeting card.
Every year I write summer greeting cards to my friends.
Last week a summer greeting card arrived from a business partner.