or as the Scots say it:
If the hart and the hind meet dry and part dry on Rood day fair,
For six weeks of rain there'll be nae mair [no more].
If dry be the buck's horn on Holyrood morn,
'Tis worth a kist [chest] of gold;
But if wet it be seen ere Holyrood e'en
Bad harvest is foretold.
There are generally three consecutive windy days about the middle of September.
According to the story, the victorious Emperor carried the Cross back to Jerusalem, dressed (of course) in his best clothes. For some reason, though, he was stopped at the gate and could not move forward.
The Bishop (or an angel) then told him that even though he carried the Cross, he did not resemble Our Lord, who wore no costly robes or jewels. Heraclius divested himself of his attire, and barefoot, in penitential garb, carried the Cross into Jerusalem.
As recounted in the Golden Legend: And as he descended from the Mount of Olives and would have entered by the gate by which our Saviour went to his passion, on horseback, adorned as a king, suddenly the stones of the gates descended and joined them together in the gate like a wall, and all the people was abashed. And then the angel of our Lord appeared upon the gate, holding the sign of the cross in his hand, and said: When the king of heaven went to his passion by this gate, he was not arrayed like a king, ne on horseback, but came humbly upon an ass, in showing the example of humility, which he left to them that honour him. And when this was said, he departed and vanished away. Then the emperor took off his hosen and shoes himself, in weeping, and despoiled him of all his clothes in to his shirt, and took the cross of our Lord and bare it much humbly unto the gate. And anon the hardness of the stones felt the celestial commandment and removed anon, and opened and gave entry unto them that entered.
Several ways to celebrate this important feast can be found at Catholic Culture, including recipes for Hot Cross Buns (normally seen on Good Friday, but equally good today).
Gardening: The 'royal herb' Basil is associated with this day, as the story is that Saint Helena found the Cross after digging under a bed of basil. My recipes using basil are here.
Also, "On Holy Cross Day, vineyards are gay"
andThis is a traditional day to go nutting.
Chestnuts are starting to drop now, so roasting chestnuts would be a nice late-summer evening activity (go here and here for instructions on roasting). If you aren't near any chestnut trees (I'm so sorry), you can buy them fresh or in jars. And then, since 'vineyards are gay' today, enjoy the roasted chestnuts with a glass of port, a delightful tradition I picked up from a Portuguese neighbor.