Sydäntalvella - In the middlewinter [a very old and strong word, directly translated "Heart winter"]
[This song is originally a poem of Saima Harmaja, a finnish poet from the early 1900's. According to the band itself she's been a great influence on their lyrical output, as one might guess from their name]
Luona lamppuni lämpöisen --- At my warm lamp
Kuluu hetkien kulta --- Passes the gold of the moments ["gold (of something)" in Finnish usually means the best or the dearest of something]
Vielä pimeys ahmaisten --- Yet didn't the darkness, by devouring, ["devour" as in swallow quickly with a single bite]
Ei sua ottanut multa --- Take you from me [pretty hard to translate the last two lines in this order, but you get the point]
Sadun puutarhan aukaiset --- You open the garden of (the) fairytale
Sinne kahden me jäämme --- There we stay twofold ["stay" or "are left", just the two of [bad word] kukkivat, tuliset --- The fiery roses bloom
Hetken ympäri päämme --- Around our head(s) for awhile [the direct translation would be "our head"] [bad word]  [bad word] ikkunaa --- Hear, lashing the window [as in whip lashes. The Finnish [bad word] directly from "whip"]
Viuhuu lumiset siimat --- Birr the snowy strings ["birr" as in go by or fly quickly with a windy sound, string as in something long and very thing. The same word is used in Finnish for a fishing line]
Meren aavalta raivoaa --- From the open (of the) sea rages
Sydäntalviset viimat --- The breezes of the middlewinter [directly translated "the middlewintery breezes"]

Vasten yötä ja pimeää --- Against/Into the night and the dark [can be understood as either one]
Täytyy lähteä miehen --- man must leave
Valo ikkunan häilähtää --- light of/(from) the window flashes ["flash" as in very gently and almost accidentally]
Vielä hetkeksi tiehen --- To the road for a (one last) moment
Luona lamppuni viipyen --- Staying by my lamp [can be translated also as staying without a reason or when you should for example be elsewhere]
Sitten muuta en tiedä --- After that I don't know (anything) else
Näen myrskyssä poikasen --- I see a boy/youngster in the storm
Käyvän kuilujen viertä --- Walking beside chasms/gorges