January is the first month of the year in theJulian andGregorian calendars. Its length is 31 days. The first day of the month is known asNew Year's Day. It is, on average, the coldest month of the year within most of theNorthern Hemisphere (where it is the second month of winter) and the warmest month of the year within most of theSouthern Hemisphere (where it is the second month of summer). In the Southern hemisphere, January is the seasonal equivalent ofJuly in the Northern hemisphere and vice versa.
Ancient Roman observances during this month includeCervula and Juvenalia, celebrated January 1, as well as one of threeAgonalia, celebrated January 9, andCarmentalia, celebrated January 11. These dates do not correspond to the modern Gregorian calendar.
Adoration of the Magi, Epiphany, January 6January, from theTrès Riches Heures du Duc de BerryIn recent decades, the number of warm temperature records in January has outpaced cold records over a growing portion of Earth's surface.[1]
Traditionally, the originalRoman calendar consisted of 10 months totaling 304 days, winter being considered a month-less period. Around 713 BC, the semi-mythical successor ofRomulus, KingNuma Pompilius, is supposed to have added the months of January andFebruary, so that the calendar covered a standard lunar year (354 days). AlthoughMarch was originally the first month in the old Roman calendar, January became the first month of the calendar year either under Numa or under theDecemvirs about 450 BC (Roman writers differ). In contrast, each specific calendar year was identified by the names of the twoconsuls, who entered office on March 15th until 153 BC, at which point they started entering office on January 1st.
Various Christian feast dates were used for theNew Year inEurope during theMiddle Ages, including March 25 (Feast of the Annunciation) and December 25. However, medieval calendars were still displayed in the Roman fashion with twelve columns from January to December. Beginning in the 16th century, European countries began officially making January 1 the start of the New Year once again—sometimes calledCircumcision Style because this was the date of theFeast of the Circumcision, being the seventh day after December 25.
Historical names for January include its original Roman designation, Ianuarius, theSaxon termWulf-monath (meaning "wolf month") andCharlemagne's designation Wintarmanoth ("winter / cold month"). InSlovene, it is traditionally calledprosinec; the name, associated withmillet bread and the act of asking for something, was first written in 1466 in theŠkofja Loka manuscript.[3]
According toTheodor Mommsen,[4] 1 January became the first day of the year in 600AUC of the Roman calendar (153 BC), due to disasters in theLusitanian War. A Lusitanian chief called Punicus invaded the Roman territory, defeated two Roman governors, and killed their troops. The Romans resolved to send a consul toHispania, and in order to accelerate the dispatch of aid, "they even made the new consuls enter into office two months and a half before the legal time" (March 15).
^"Mean Monthly Temperature Records Across the Globe". National Centers for Environmental Information (NCEI) of the National Oceanic and Atmospheric Administration (NOAA). Link is an example for one month; for other months, change the "202501" in the preceding URL toyyyymm, whereyyyy is the four-digit year andmm is the two-digit month (01=January through 12=December)
