Warming trend: Do bats heat up with weather?

Warming trend: Do bats heat up with weather?

Warming trend: Do bats heat up with weather?
With June just around the corner, ballparks across the country are starting to experience warmer temperatures, and with that will come warmer bats, right?

Everyone has heard coaches and players mutter the cliché at some point, but is there actually any substance to the claim that hitting gets better once it warms up? Or is that nothing more than an excuse for early-season slumps?

Unfortunately, there's no way to strictly isolate a player's performance based on the weather.

On an individual level, while an improvement from April to May could potentially be the result of warmer air circulating through the stadium, it could also simply be a sign that a player is working through some leftover kinks from the offseason. Evaluating overall team statistics doesn't provide a clear answer, either, considering that managers sometimes give up on slumping players in favor of guys who come in and put up better numbers by the time the warmer midseason months roll around.

All outliers aside, there are stats that suggest it might not be time to panic just yet for ballclubs mired in early-season hitting ruts. As is usually the case with stats, though, there are also a few that would indicate team averages might not necessarily rise with the temperatures in places like Pittsburgh or Chicago.

For the Cubs, manager Dale Sveum was hoping that the increased temperatures on the North Side of Chicago would solve his team's early offensive woes, which included a .242 batting average in April.

"New month, obviously, and the weather warming up and things like that will play into hitting more home runs," Sveum said at the beginning of May. "Would we have more than we have now if the weather was different and the wind wasn't blowing in [at Wrigley Field]? Of course we would."

BRING THE HEAT
Of the 13 teams that play in cities where the average high in April is below 65 and the average high in May is above that mark, seven have seen their home batting averages actually decline from April to May.
Team April May
Brewers .244 .274
Cubs .242 .232
Indians .215 .254
Mets .239 .243
Orioles .266 .242
Phillies .259 .277
Pirates .235 .191
Red Sox .307 .260
Rockies .291 .249
Tigers .250 .269
Twins .298 .229
White Sox .229 .254
Yankees .280 .257
As it turns out, Sveum might have been on to something about the home runs -- they have nine in 11 games at Wrigley this month after hitting just five in 13 contests there last month. He'd be happy to have that .242 average back, though, as the Cubs' average has actually dropped 10 points within the Friendly Confines in May.

The Cubs aren't alone, though. Of the 13 teams that play in cities where the average high temperature is below 65 in April and above that mark in May (Baltimore, Boston, Chicago [2], Cleveland, Colorado, Detroit, Milwaukee, Minnesota, New York [2], Philadelphia and Pittsburgh) seven have seen their home batting averages decline this month. As for the power numbers, only five of those teams are hitting the ball out of their home ballpark at a higher clip in May than they did in April.

Red Sox slugger David Ortiz, a notorious slow starter, knows as well as anyone what these teams are going through -- and he certainly doesn't see a slow start as a death sentence.

"I always say it doesn't matter what you do in April, it matters what you do in September," said Ortiz, who broke the .300 mark in April for only the third time in his career with his .405 average last month. "I'm just going to keep on playing and try to keep winning."

Whether a result of the weather, teams settling into a groove or managers having found the best lineup combinations, the past seven years suggest the best offense is yet to come this season.

Since 2005, the month with the highest league-wide batting average has always come in June or later. In those seven seasons, the highest league average by month came twice in June, once in July, twice in August, once in September and was split evenly between July and August in the 2008 campaign.

Likewise, the lowest average by month came most frequently in April. The season's opening month has laid claim to the worst league average in four of those seasons, while the season's final month has taken that distinction twice. The 2009 campaign was somewhat of an anomaly, with players hitting .263 in both April and May before dipping to a season-low .255 in June.

Tigers manager Jim Leyland has been around the game long enough to know that -- for whatever reason -- offenses do seem to start clicking when the mercury starts rising. That doesn't mean he's any more accepting of the way his team has stumbled out of the gates for a second straight season.

Last year, the Tigers hit .254 at Comerica Park in the month of April and an even worse .249 in May before breaking out the lumber to the tune of a .292 home batting average in June. Not surprisingly, Detroit jumped from five games back of the Indians in the American League Central at the start of June to the top of the division by month's end.

Leyland is watching a similar situation unfold this year, with his club sitting in third place behind the Indians and White Sox, five games off the pace entering play Thursday. The good news is the Tigers have hit .269 at Comerica Park this month, up from the disappointing .250 in April -- but still not quite the breakout month Leyland was hoping for.

"You can't just sit around and say, 'Well, it will come,'" Leyland said earlier this month. "Everybody's saying, 'Well, the offense around this time last year was struggling.' And that's true. It's not good to have a sense of urgency, but it's also not good if you think everything will just automatically happen. You got to go out and make it happen."

It just might happen a little quicker as players start ditching their long sleeves.

Paul Casella is a reporter for MLB.com. Follow him on Twitter @paul_casella. This story was not subject to the approval of Major League Baseball or its clubs.