As the bulk part of the "Summer Break" in the Northern Hemisphere, August feels like the height of summer. In reality, it is a time when the fruits ripen and the climate is already changing for Autumn.
August
Our name for August derives from the Roman name for the month -- Augustus. Originally, the month was named Sextilis, as it was their sixth month. It was renamed in 8 BC in honour of emperor Augustus. Having renamed Quintilis (July) after his predecessor, Julius Caesar, he chose Sextilis for himself, it is said, because it was a month when he had won many victories. Previously known as Octavian, Augustus is a name that the emperor assumed for himself in 27 BC. It was a clever political move on his part. Not wanting to associate himself with the previous, and unpopular, kings of Rome -- something the Roman republicans were highly suspicious of -- he instead chose a religious term that translates roughly as "illustrious one", "venerable" and "majestic." It was adopted by succeeding emperors, eventually becoming more of a title than a name.
As such a notable and historic name, it is not surprising that Augustus has many variants. Augustinus, Augusta and Augustina were adopted by the Romans themselves, while later variations include August, Augustin, Augustine, Austin, Auguste, Augusto and Agostino.
The Greek equivalent to the title Augustus was Sebastianos, the route of Sebastian. Many Greek-speaking Roman cities were given the name Sebastia or Sebaste in honour of Augustus, or a succeeding emperor.
Harvest
The Anglo-Saxons called August Weod-mónaþ. Weod is the word from which we get 'weed', but it could also simply mean grass or herbs. To the Germanic peoples it was known as Erntemond "harvest month," a theme reflected in the West Frisian (Rispmoanne) and Finnish (Elokuu) names for August. For centuries, the harvests have begun in August, as the plants ripen, and continue through September.
Many ancient gods, goddesses and demi-gods have been associated with harvest. The ancient Greeks connected Demeter, Carme, Carmanor, Linus and Chrysothemis with harvest. The Romans recognised Mercury, Ceres, Feronia and Consus as such. Rauni was a Finnish harvest-goddess, while Jarilo was a Slavic harvest-god.
Lughnasadh 
August 1 marks the ancient Celtic festival of Lughnasadh, an event that celebrates the first harvest. Lughnasadh is Irish in origin, though it matches up very nicely with the British Lammas. The name derives from the Irish god Lugh, an important deity, cognate with the Welsh Lleu, who ultimately descends from the ancient Celtic god Lugus. Sereval old Irish names are descended from Lugh, including: Lughaodh, Lugaid, Lughan, Lughna, Luithiarn and Luiseach.
The name is commonly believed to derive from the Proto-Indo-European *lewko- "to shine"* and is therefore a relative of the Latin lux derivatives -- Lucius, Lucan, Lucy, Luciana and the like. Lugus is thought to have been the Celtic version of the Norse god Odin. When the Romans came in to contact with Celtic tribes, they connected Lugus with Mercury.
Symbols
Peridot is the birthstone for August. It is a precious gemstone, known for its protective, healing and strengthening qualities. Peridot has been used on rare occassion as a feminine first name from the late 19th century. Peridot is a type of Olivine, which has also seen usage as a girls' name from the late 20th century. Its usage was higher than Peridot, no doubt due to its similarity with the popular Edwardian name Olive.
The Poppy is August's birth flower which, in Britain, is known as the flower of remembrance, an association used since the Victorian era. Poppy, currently, is very popular for girls in Britain, but has been in use as a name from the mid-19th century, occasionally for boys but more often for girls.
Leo, "the lion", is the astrological sign that runs from July 23 - August 22. Several names contain an element that translates as "lion", such Leon, Leonard, Leonardo, Leonidas, Leoline, Leontius, Leona, Leonie, Leontina and Leontine.
Leo, of course, is used as a name in its own right, but there are also several longer forms (such as Leopold, Leofric, Leocadia and Leonora) that, although they don't relate to "lion", can easily use Leo as a nickname.
The Welsh word for "lion" is llew, which is a possible source for Llewellyn. Alternatively, the name may instead be derived from Lleu (see above), still making it a highly appropriate August name.
Name Days
Many different countries have names associated with days of the year; most often they are the feast days of saints. Below are some of the names associated with the days in August around the world.
1 = Alphonso, Peter, Faith, Hope, Charity, Sophia
2 = Eusebius, Gustav, Julian, Karin(a), Lonán, Stephen
3 = August, Lydia, Nikodemus, Oliver, Stephen
4 = Arnold, Dominic, Rainer, Maximilian, Veera
5 = Afra, Oswald, Nieves, Nona
6 = Christi, Justus, Salvador, Sotiris, Sotiria
7 = Albert, Cajetan / Gaétan, Donata, Donatus
8 = Dominic, Emil, Emilia, Justin, Sylvia
9 = Edith, Lawrence, Roland, Roman
10 = Asteria, Astrid, Blane, Laurence, Lars, Lorenzo
11 = Clare / Klara, Herman, Philomena, Susanna
12 = Clare / Clarisse, Hilaria, Lech
13 = Cassian, Hippolytus, John, Marco
14 = Eusebius, Felix, Maximilian
15 = Johanna, Mac-Cartin, Maria, Stella
16 = Joachim, Rocco / Roch, Stephan, Stephanie, Theodore
17 = Gudrun, Hyacinth, Liberat, Miron / Myron
18 = Agapitus, Claudia, Flora, Helena
19 = John, Magnus, Sebald, Tekla, Timothy
20 = Amator, Bernard, Leontius, Samuel
21 = Jane / Joanna, Maximilian, Pia, Pius
22 = Hippolytus, Ivo, Regina, Sigfried
23 = Philip, Rose / Rosa, Signe, Zacchaeus
24 = Bartholomew, Bertold, Isolde, Michaela
25 = Ebba, Joseph, Louis, Louisa, Patricia
26 = Adrian, Ilma, Margaret, Natalia, Zephyrin
27 = Cesarius, Monica, Raoul, Rufus, Vivian
28 = Adelina, Augustine, Hermes, Julian
29 = Beatrice / Beatrix, John, Sabina
30 = Albert, Alexander, Benjamin, Felix, Herbert
31 = Aidan, Arvid, Paulina, Raymond
