of the L-rd which was at the north; and there were there women sitting, bewailing the Tammuz" (Yechezkel 8:14)
"Tammuz" is the Babylonian name of this month, as are all of the "official" names of the months in the Hebrew Calendar. In the Bible, however, the month is referred to as "the Fourth Month," with reference to Nisan, the First Month.
Biblical Significance of the Month
As mentioned above, the name which "came up" from Babylon with the Jewish People was Tammuz. In this case, consideration of the use of the name in Yechezkel would make it appropriate to say that the name "Tammuz" brought down the Jewish People. The verse in Yechezkel cited above speaks of the worship of a Babylonian idol, known as "Tammuz." And it seems most odd, at first glance, that this name would be chosen as the name of a Hebrew month.
However, in the context of the month that we are dealing with, a month of tragedies which would lead to still greater tragedies, the appropriateness of the name becomes clear. The Prophet Yechezkel was being shown by G-d the reasons for His great Anger against the Jewish People, namely, the various forms of idol-worship which had been adopted by them to replace the Divine Service. This behavior would result, if the Jewish People would not repent, in the Destruction of the Once-Holy, but now desecrated, Temple.
Earlier Biblical Significance
We read in the Book of Yehoshua (10:11-14) of the Battle of Yehoshua and the People of Israel against the five kings of the Emorite Nation. In the Biblical account, we find mention of "great stones" thrown, as it were, by G-d, upon the Emorites. This could refer to hail, as the verse itself mentions (Yehoshua 10:11).
But in light of the great astronomical miracle detailed in the following verses (12-14), in which the sun and the moon are pictured as having not advanced, until the People of Israel had achieved complete victory, there is here the suggestion of a tremendous suspension of the paths in Heaven, perhaps caused by a contact of the Solar System with an intense meteor, or asteroid, shower.
Whatever the case, according to Jewish tradition, this great miracle is supposed to have occurred on the third of Tammuz.
Zodiac Sign of the Month
The "sign" of the month is "Sartan," "Cancer," or "The Crab," because a constellation which is observed at this time of year has the appearance of a crab. Also, the season is summer, and the hot weather of summer causes crabs to multiply in the water.
Crabs pinch and hurt, and this month was basically a time in which the Jewish People were hurt.
• Significance of Astrology in Judaism
Chodesh Tammuz - In Relation to the Other Months of the Year
3 Sivan (30 days)
4 Tammuz (29 days)
5 Av (30 days)