He was convicted in February of abusing two pupils at Altrincham Grammar School in Greater Manchester.
The crimes are said to have taken place on school trips in 1975 and 1976.
The 65-year-old was cleared of eight other charges of indecent assault after a three-week trial at Manchester Minshull Street Crown Court.
He denied abusing boys aged 14 to 17, but was found guilty of two counts relating to assaults on former pupils on canal boat trips.
Talbot is best known for presenting the weather on ITV's This Morning programme from a floating map at Liverpool's Albert Dock.
But before his media stint, the Edinburgh-born TV star worked as a biology teacher at the boys' school until May 1984.
The jury at his trial heard his teaching career came to "an abrupt end" following an indecent proposal he made to two pupils he invited to his home to look at his telescope.
At the end of the trial, judge Timothy Mort told Talbot, from Bowdon in Greater Manchester, his sentence would start immediately bearing in mind his "abuse of trust".
Talbot was also questioned by Greater Manchester Police about an alleged serious sexual assault on a former pupil, but the investigation was shelved after the complainant died.
A number of similar complaints against Talbot have been passed by police to the Procurator Fiscal Office in Scotland.
The investigation was triggered in December 2012 following publicity into a separate historical abuse inquiry at another Altrincham school, St Ambrose College, which led to a nine-year jail term for ex-teacher the Reverend Alan Morris.
Former TV weatherman Fred Talbot, convicted of indecently assaulting two teenage boys when he was a teacher, is due to be sentenced later.