The temperature warmed up in Cleveland in May, as did Indians second baseman Jason Kipnis. May was filled with incredible statistical performances by Kipnis, Bryce Harper and others, but it was the Indians second baseman that owned the month of May.

Kipnis joined an exclusive club, with names like Babe Ruth, Lou Gehrig and Hank Aaron as he posted a 1.217 OPS with 51 hits and 30 runs.

Kipnis led the MLB, posting a 3.1 fWAR in the month of May, a full 0.5 fWAR better than the second best hitter in May, Harper. No other player in this decade has reached a fWAR higher than 3. If he were able to keep this pace up, which unfortunately for Indians fans is unlikely, he'd be a shoo-in for the AL MVP. Kipnis was the most valuable player in baseball, based on fWAR, in the month of May.

In May, Kipnis batted .429/.511/.706 with a .512 wOBA and 241 wRC+, numbers absolutely off the charts. He struck out just 11.9 percent of his 143 plate appearances, walking in 11.2 percent of them. He posted an Isolated Power (ISO) of .277 as he hit four home runs, adding 15 doubles, three triples and 17 RBI. Baseball is a game where even the best are out more times than they are safe. In May, Kipnis, with a .511 OBP, was safe more times than he was out.

Kipnis led, or was in the top five of every major hitting category for the month of May. He led the MLB in May in batting average and on base percentage, and finished second to Harper in slugging percentage, weighted on base average (wOBA) and adjusted weighted runs created (wRC+). And while not a power hitter, having only hit four home runs in May and five the entire season, his ISO ranked 18th in the Majors.

Simply, Kipnis went from a hitter who was struggling to regain his form after last season to one of the best hitters in the MLB in the span of a month. Before May, Kipnis was hitting .218/.263/.287 with a .245 wOBA and 55 wRC+. These numbers put him far behind the pack. Kipnis was struggling. He was walking less than in previous years and didn't look like he'd return to his 2013 form when he posted a 4.4 WAR, earning himself a long-term extension.

But that all changed in May. With Michael Bourn struggling, Kipnis was moved to the leadoff spot and from then on he shined. In the leadoff spot, Kipnis started getting more pitches to hit. The number of fastballs he received (FB%) increased from 57.1 percent to 62.2 percent, and Kipnis started hitting them. His line drive percentage (LD%) jumped from 21.3 percent to 34.0 percent, while his fly ball and groundball percentage both dropped. In addition, Kipnis began hitting the ball harder, a 33.3 hard hit percentage in May compared to just 21.1 percent in April.

And as he began to hit the ball better, Kipnis started to play much better. His BABIP, .240 in April, skyrocketed upward to .475 in the May. And with it, so did his hitting stats, as his average, on base percentage and slugging percentage all skyrocketed as he turned into an absolute monster in May, helping the Indians to a 17-12 record in the month.

For the season, Kipnis is hitting .340/.411/.529 with a .403 wOBA, 165 wRC+ and 3.1 fWAR. He's striking out 12.6 percent of his plate appearances and walking in 8.8 percent. He ranks third in the Majors in fWAR behind Harper and Josh Donaldson, fourth in average, ninth in on base percentage, 13th in weighted on base average and 11th in adjusted weighted runs created.

Kipnis ranks 11th in numberFire's nERD statistic, which measures the number of runs contributed over the league-average per game.

But with a .374 BABIP, Kipnis cannot be expected to perform at this high of a level the rest of the season. Some regression is likely, but how much remains to be determined. numberFire projections predict Kipnis to hit .253/.328/.376 with a .313 wOBA the rest of the season, while ZiPS projections are a little more generous, projecting Kipnis to hit .274/.348/.418 with a .336 wOBA, 118 wRC+, .321 BABIP and 2.7 fWAR. ZiPS rest of season projections predict Kipnis will be a 5-WAR player a stat that would put him among the best hitters in the MLB and possibly put him in the discussion for the MVP.

A 5-WAR season for Kipnis would certainly be a bounce back year for the Indians second baseman and signal a real emergence as one of the better hitters in the American League. Prior to last season, Kipnis posted a 4.7 fWAR in 2013 and things were looking up. But his 2014 season was derailed by a finger injury early on and Kipnis as barely above average last season, posting a 0.8 fWAR. If Kipnis can continue his upward trend, then the future looks bright for the Indians second baseman.