How much do natural effects (temperature, air pressure and elevation) change the distance a baseball is hit?

Question: How much do natural effects (temperature, air pressure and elevation) change the distance a baseball is hit?

Note: I made a major math error previously and temperature had too much of an effect on the ball, I took 4 ft for every degree F, instead of every 10 degrees F. The current values are updated and hopefully correct.

Note: Here is the link to all Major and Minor league stadiums with information on natural effects, stadium size and park effects.
http://66.37.156.70/Ballpark_info.xls

Note: Article in By the Numbers that addresses temp and offensive production:
http://www.philbirnbaum.com/btn2008-05.pdf

Why I asked the question? I wanted this answered for several reasons. Do batters heat up during the summer or does the ball travel farther? Is pitching better in the playoffs or is it just cooler temperature limiting offense? Which parks, do to their elevation, become a hitters park? Does the ball fly further in Tucson (which 1200 ft higher) vice Phoenix area (~10 degrees warmer) during spring training?

Analysis: The changes in baseball fight distance I from natural effects are from the book “The Physics of Baseball” by Robert K Adair. There is a brief summary of the book at:

http://www.bostonbaseball.com/whitesox/baseball_extras/physics.html

The three effects I wanted to take into account were temperature, air pressure and elevation. Here are the effects each one has on a ball hit 400ft:

1000 feet of increase in altitude	+7 Feet
10 increase in degrees of air temp	+4 Feet
1 inch drop in Barometer	+6 Feet

Initially for this study I look at all the major league stadiums and all the stadiums that the Royal's utilize. I will am currently getting the information on all parks and will add them as I collect the information. I compared all hit balls using a baseline of a stadium at sea level that is at 70 degrees F and at 29.2 in of pressure. Elevations were collected from various location while the weather information was collected from:

http://www.worldclimate.com/

Note: I had problem getting pressure for all location and those that don't have pressure information are marked with an asterisk (*).

Major League Baseball Team	Park	Average size of stadium	April	May	June	July	Aug	Sept	Oct
Arizona Diamondbacks	Chase Field	381.5	407	411	415	417	417	414	409
Atlanta Braves	Turner Field	372.8	402	406	409	409	409	407	402
Baltimore Orioles	Oriole Park at Camden Yards	364.7	394	398	402	404	403	400	395
Boston Red Sox	Fenway Park	364.8	391	395	399	401	400	397	392
Chicago Cubs	Wrigley Field	374.0	396	400	404	406	405	402	398
Chicago White Sox	U.S. Cellular Field	369.2	396	400	404	406	405	402	398
Cincinnati Reds	Great American Ball Park	368.3	397	401	404	406	405	402	397
Cleveland Indians *	Progressive Field	367.5	396	400	404	405	405	402	398
Colorado Rockies	Coors Field	382.0	428	432	435	438	437	433	428
Detroit Tigers	Comerica Park	375.0	395	399	403	405	404	401	396
Florida Marlins	Dolphin Stadium	367.5	401	403	404	404	405	404	403
Houston Astros *	Minute Maid Park	374.3	400	402	404	405	405	404	400
Kansas City Royals *	Kauffman Stadium	376.7	399	403	407	409	408	405	401
Los Angeles Angels of Anaheim	Angel Stadium of Anaheim	369.5	397	399	400	402	403	402	400
Los Angeles Dodgers	Dodger Stadium	365.0	400	401	402	404	405	404	402
Milwaukee Brewers *	Miller Park	371.0	394	398	402	404	404	401	397
Minnesota Twins	Hubert H. Humphrey Metrodome	373.0	407	407	407	407	407	406	406
New York Mets	Shea Stadium	374.6	393	397	400	402	402	398	394
New York Yankees	Yankee Stadium	372.0	393	397	400	402	402	399	394
Oakland Athletics	Oakland-Alameda County Coliseum	365.7	394	395	397	397	398	398	396
Philadelphia Phillies *	Citizens Bank Park	373.6	393	397	401	403	402	399	394
Pittsburgh Pirates	PNC Park	366.8	397	401	405	406	405	402	398
St. Louis Cardinals	Busch Stadium	370.2	397	401	405	406	406	402	397
San Diego Padres	PETCO Park	375.1	396	397	398	400	400	400	398
San Francisco Giants	AT&T Park	375.0	394	394	395	395	396	397	396
Seattle Mariners	Safeco Field	373.8	391	394	396	397	397	395	393
Tampa Bay Rays *	Tropicana Field	364.2	400	400	400	400	400	400	400
Texas Rangers *	Rangers Ballpark in Arlington	373.8	402	405	408	410	410	407	403
Toronto Blue Jays	Rogers Centre	367.7	391	395	399	401	401	397	393
Washington Nationals	Nationals Park	370.3	394	398	401	403	402	399	394

Royal's Baseball Teams	City	State	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov
Kansas City Royals *	Kansas City	Missouri			399	403	407	409	408	405	401
Omaha Royals	Omaha	Nebraska			400	404	408	410	409	406
Northwest Arkansas Naturals *	Springdale	Arkansas			405	407	411	413	412	409
Wilmington Blue Rocks	Wilmington	Delaware			394	398	401	403	403	400
Burlington Bees *	Burlington	Iowa			397	402	405	407	406	403
Arizona League Royals	Surprise	Arizona					414	417	416	380
Burlington Royals *	Burlington	North Carolina					406	408	407
Honolulu Sharks	Honolulu	Hawaii								404	404	403
Surprise Rafters	Surprise	Arizona								413	408	403
Idaho Falls Chukars *	Idaho Falls	Idaho					429	432	431	428
DSL Royals	Santiago de los Caballeros	Dominican Republic				405	406	406	406	406
Spring Training	Surprise	Arizona	402	404