Since summer has officially begun, the deity to whom we turn today is one closely associated with the summer, the Babylonian Tammuz. The god was originally known as Dumuzi in Sumeria, but is much better known by his Semitic name, due to the month with that name. It was originally a Babylonian summer month, but the Jews came to use the name as well, and it’s now part of the Jewish calendar. It’s apparently also the name for the corresponding month in Iraqi and Levantine Arabic. The month received the name because it was when the people mourned for the god.
Tammuz was a god of vegetation, and his story was yet another example of the death and resurrection cycle that also showed up in the myths of Osiris, Attis, and Adonis, not to mention Jesus. It appears that the most popular version of the Tammuz myth shows the deity as a shepherd and the consort of Inanna, Queen of Heaven (or her counterpart Ishtar). Tammuz is somehow killed, and Inanna has to descend into the underworld to rescue him. Either that, or the sacrifice of Tammuz was part of a deal between Inanna/Ishtar and her sister Ereshkigal, ruler of the dead.
Regardless, Tammuz was restored to life, and he now divides his time between the world of the living and that of the dead, sort of like Persephone. His death is commemorated at the beginning of summer, when the days begin to grow shorter. While these vegetation deities who were killed and reborn were quite common, the time of year when these events took place varied, most likely depending on the climate in which the local myths were written.
The cult of Tammuz wept for the dead god in the month that bears his name, and the Bible even makes mention in Ezekiel 8:14 of women in Jerusalem weeping for the Babylonian deity. Not surprisingly, Yahweh and Ezekiel see this as an abomination, but another passage perhaps condones a Jewish equivalent of the practice (and no, I’m not talking about Jesus). I think it’s just speculation at this point, but I’ve seen suggestions (including one from Asimov’s Guide to the Bible, I believe) that there might be a connection to the story in Judges 11 about Jephthah sacrificing his own daughter in order to win a battle. The tale includes a bit about the women of Israel spending four days of every year mourning for Jephthah’s daughter, which might have simply been an attempt to bring to incorporate the already existing weeping for Tammuz into a developing monotheistic religion. If so, the practice must have fallen into disfavor by the time of the Babylonian conquest, hence Ezekiel’s condemnation.