A trip to local(ish) rivals Lincoln City on New Years Day offered Posh a chance to right their wrongs from the previous year, but they made the worst possible start to 2020 with a 2-1 loss at Sincil Bank.
Things had started well for Posh, with Ivan Toney scoring their first goal in three Sky Bet League One matches. To be fair to Lincoln, they played well and roared on by a big home crowd they equalised when Tyler Walker's shot was deflected over Christy Pym and into the back of the net.
What happened shortly after the equaliser changed the game in the host's favour and cost Posh dearly.
Just a minute after coming onto the pitch, Sikiri Dembele was adjudged to have headbutted Lincoln City's Joe Morrell and was shown a straight red card.
Posh managed to hold on until the final minute of the 90 when Jorge Grant curled in a free-kick for the Imps to hand Posh defeat in their opening game of the new decade.
Next up for Peterborough United was a welcomed break from league action. Posh hadn't won in four games, so while a trip to Premier League side Burnley didn't exactly offer them a good chance to stop the rot, it gave them a chance to challenge themselves against a top tier team.
After 23 minutes, many Posh fans would have wished they didn't make the journey. Goals from Jay Rodriguez, Erik Pieters, and Jeff Hendrick saw the Clarets race into a three-goal lead early on, before Ivan Toney scored to reduce the arrears.
Any hopes that Posh had of a second-half comeback were quickly put to bed just seven minutes after half-time when Rodriguez scored his second of the afternoon. Ricky-Jade Jones managed to get us name on the scoresheet for Posh to make it slightly more presentable, but Posh were beaten 4-2 and consequently knocked out of the FA Cup.
Posh's four-match losing streak finally ended in their Sky Bet League One match with Gillingham, but it certainly wasn't the result that they had hoped for.
They were held 0-0 at home by former boss Steve Evans, and truth be told his Gillingham side probably did deserve to win.
Despite Gillingham's performance, Posh could have stolen it right at the end when Ivan Toney was through on goal, but Peterborough's main man wasted the opportunity.
Up next for Posh was a trip to Sky Bet League One strugglers AFC Wimbledon and although Posh suffered defeat, it sparked a change from manager Darren Ferguson, who finally decided to drop his diamond set-up.
Posh lost 1-0 at Kingsmeadow, with some poor defending allowing Joe Pigott to score the only goal of the game. Despite an improvement (and change of formation) in the final 30 minutes, Posh couldn't find the back of the net.
After losing to relegation-threatened AFC Wimbledon, Posh then faced second-place Wycombe Wanderers on a Tuesday night under the lights at London Road.
Darren Ferguson changed formation from the start, with Posh lining up with a three-man defence.
It seemed to work from the off, as Posh ran rampant, opening the scoring from the penalty spot after 23 minutes.
Sammy Szmodics was fouled by Giles Phillips, who was consequently sent off, and Ivan Toney made no mistake from 12 yards out.
Toney turned provider after 44 minutes, playing a neat one-two with Sikiri Dembele, who finished well to double Posh's lead just before half time.
The second half started in similar fashion with Posh on the front foot, and they put the game beyond any doubt 11 minutes after the break when Jack Taylor grabbed his first goal for Posh to make it 3-0.
The scoring wasn't done there and it was the main man Ivan Toney who made it 4-0, finishing expertly after Reece Brown's long-distance effort was parried by Ryan Allsop in the Wycombe Wanderers goal.
Peterborough United's return to winning ways excited the fans, but an even trickier task lay ahead for Darren Ferguson's side as they prepared to welcome league leaders Rotherham United to London Road.
The match against the Millers got off to the best possible start, as Ivan Toney was put through by Sikiri Dembele, with Posh's top scorer making no mistake to give Posh the early lead inside two minutes.
Posh were looking comfortable, and their lead was doubled in the 22nd minute when Sammy Szmodics scored his first goal for Posh after excellent build-up play down the left-hand side.
The final goal of the game came as early as the 35th minute when defender Michael Ihiekwe capitalised on poor marking to volley home and half the deficit.
Despite a late penalty appeal from Rotherham, Posh held on to record an impressive victory.
Posh's final game in January was not one that appealed to many people, and understandably so. 192 fans made the long trip to Lancashire to watch Posh take on Accrington Stanley on a cold night in the North West.
Despite dominating possession, Stanley never got close to Peterborough, who took the lead 11 minutes in when Sammy Szmodics deflected effort beat the keeper at his near post.
Their lead was doubled just six minutes after the break when Ivan Toney selflessly put the ball on a plate for Joe Ward, who made no mistake on his 100th appearance for the club.
Posh were comfortable and held on for their third successive victory, and their first away win since October.