Summary: The Finnish given name Jukka belongs to a very large and diverse group of names, such as English John, Russian Ivan, and Italian Giovanni, originating in Hebrew Johanan (Latinized form: Iohannes). It is relatively common especially among men born in the 1950s.
The Hebrew name Johanan (or Jochanan, or with initial Y instead of initial J, depending on the transliteration), originally meaning 'God (J*hw*h) is merciful/gracious', occurs frequently in the Bible (John the Baptist, John the Apostle, and others). Through its Greek or Latin form (Ioannes, Iohannes, Johannes), it has given rise to a very large set of first names (given names, Christian names) in countries affected by Christianity. See the description of the name John in Mike Campbell's Behind the name.
In English, the name John is often used as a generic male name, frequently with a more or less negative connotation. There doesn't seem to be anything similar to that in Finnish for the name Jukka or any other member of the group of names.
Due to various phonetic changes, the names are often difficult to recognize on first sight. To mention a few of them:
|Danish||Jens, Johan, Jan|
|Estonian||Jaan, Juhan, Ants|
|Gaelic||Iain (anglicized version: Ian)|
In Finnish, there are several names in this group: Johannes, Hannes, Juhani, Jussi, Janne, to mention just a few common names. They have been popular since the Middle Ages. The great variation in this group was partly caused by a person's name changing during his lifetime - the choice of a name variant might reflect age and esteem. In such a scale, Jukka was probably used about children mostly. Later modern society required fixed names.
In the current system of given names in Finland a person must have at least one and at most three given names. Typically, the first one is used in practice, although some people may start using their second or third given name if they don't like the first one. Sometimes the second or third name is a patronym, but much more typically they are selected from the same repertoire as the first given name.
Some names of this group such as Johanna are given to girls, but in such cases the female name as such has been adopted to Finnish from other languages. Then ending -a is not a feminine suffix in Finnish; in fact, Finnish lacks grammatical gender entirely. Almost all Finnish first names are either male or female, and Jukka is male.
The pronunciation of the word Jukka could be roughly characterized as "Yook-kah", with both vowels short however. You might check Kai Nikulainen's page How to pronounce Finnish names where he has a sound (WAV) file presenting "Jukka". See my notes on the pronunciation of Finnish. Although the double kk is to be read as a double consonant (a prolonged k), in most case forms, the consonant becomes single (both in spoken and written forms) according to the so-called consonant gradation in Finnish. Thus we have the forms Jukan 'Jukka's', Jukalle 'to Jukka' etc.
The form Jukka, with its double k, has differentiated rather much from its origin. One might assume that it is the product of the mere play with word forms which we so often apply to children's names, and comparable to Pekka which is a variant of Peter. But there are reports of names like Jogan and Joghan occurring in Sweden in the 13th and 14th century and assumably resulting from the previous form Jovan. Since the Finnish language lacks the voiced sound g, it is regularly replaced by k in loanwords. Thus, we would have the chain of consonant changes h > v > g > k > kk which are phonetically plausible. This is mostly just speculation. Anyway, there are written records of Jukka and Juko being in use in the 16th century in Karelia.
Among all first given names given to boys in 1880 - 1981, Jukka ranks the 20th. It was popular especially in the 50s (ranking the 8th) and 60s. In the 70s, other variants of the group of names became more popular, especially Jani, Janne and Juha. Yet, Jukka has still remained among the hundred most popular names in the 90s. .
The name day of Jukka and many other names of the same group is the 24th of June. The name day tradition in Finland is of Roman Catholic origin, originally related to memorial days of saints. Currently name days are at most small celebrations for people with the name in question, comparable to birthdays. The 24th of June was the original midsummer day, juhannus, in Finland, and the memorial day of John the Baptist; there is however very little that reminds of this in modern Finnish midsummer day festivities. The midsummer day was made a moving day in 1955; it is now the Saturday between 20th and 26th of June. However, the name day was not changed.