It is the season of burning leaves in temperate America, and a time for the quarterly marks for National Football League coaches.

By a geographical happenstance the state of Florida has two expansion teams with 4-0 records, the Miami Dolphins and the Tampa Bay Buccameers, two of the four undefeated teams in the NFL, so both coaches rate A-plus.

In Miami, where a pro football team called the Seahawks once flopped, 66,011 watched the Dolphins thrash the Chicago Bears on Sunday, 31-16.

In Tampa, where the Buccaneers have been in business only since 1976 and lost their first 26 games, 69,497 turned out to see them suffocate the Los Angeles Ram offense, 21-6.

"This was the most significant win in the history of our team because the Rams are the Rams -- a prestigious team in the National Football League," Buccaneer Coach John McKay said yesterday.

The tone of the T-shirt editorials in Tampa has changed to, "On the Eighth Day God Created the Bucs."

McKay tries to keep his job in perspective despite his team's recent success. Asked yesterday if he'd like to be famous for his professional coaching career, McKay replied: "I hope not. I want to go into the twilight with very little ink, a big fat wallet and a slow backswing."

In Miami, senior citizens are enchanted the second time around, identifying with 32-year-old prodigal son Larry Csonka, who scored three touchdowns and outrushed Walter Payton, the Prince of the Midway, 73 yards to 43. In his generosity, Payton commented, "Teamwise, I think Miami is a little better than Dallas right now."

Coach Don Shula is doing it with Don Strock, second-fiddle quarterback, while over-30-generation member Bob Griese is recuperating from a pulled hamstring muscle. Orange Bowl spectators could appreciate the handicap under which the Dolphins were persevering when tight end Bruce Hardy quarterbacked the last two plays of the game.

McKay is performing some magic with a team that averages 25 years of age and has only one player over 30, punter Tom Blanchard. McKay is demonstrating unique forbearance with sophomore quarterback Doug Williams and it is paying off. Williams went into Sunday's game with a 37.7 pass completion percentage and hit only five of 20 attempts.

But two of them went for touchdowns against the vaunted defense of the Rams. Williams bounced back from having a pass picked off and run back for a Los Angeles touchdown. He persisted in ignoring the pressures that rush men imposed on him by extending to 89 the pass attempts in which he has flitted away from sacks with his hair-trigger release.

An irony of the Buccaneers poaching on the Dolphins' once-exclusive Florida stage was that Miami inadvertently helped Tampa Bay step out to a two-game lead in the Central Dicision of the National Conference, when the Dolphins knocked off the Bears.

Joe Robbie, owner of the Dolphins, has put an end to the annual exhibition game between the two clubs. There will be none in 1980. He is understood to feel that the game was becoming an intrastate rivalry so intense that it was taking on the substance of a regular season contest.

He could have been influenced by the fact that although Miami has won all four exhibitions, Griese was hurt in the third quarter of the 1978 game and missed five regular season contests. The supposition was that Griese might not have played so long if it had been a normal exhibition with a club other than Tampa Bay.

The reason given for not meeting in 1980 was the inability to agree upon a date.

Both of the Florida football teams emphasized defense and the Buccaneers attacked the Ram offense on Sunday in the manner of the club's logo -- a boarding party of pirates.

The Buc left cornerback is Jeris White, who was drafted on the second round by Miami in 1974. Tampa Bay obtained him from the Dolphins in September 1977 for a fifth round pick. White intercepted a pass by Ram quarterback Vince Ferragamo on Sunday in Tampa Bay territory when Los Angeles was trying to rally.

The Buccaneers are prospering with three other defensive backs whose original teams considered them dispensable. Right cornerback Mike Washington was drafted on the third round in 1975 by Baltimore and Tampa Bay got him from the Colts in 1976 for a third round pick.

Strong safety Mark Cotney was drafted on the seventh round by Houston in 1975 and the Bucs took him in the expansion draft. Free safety Cedric Brown, who was drafted No. 12 by Oakland in 1976, signed with Tampa Bay in 1977 as a free agent.

Nose tackle Bill Kollar was drafted by Cincinnati No. 1 in 1973 and was obtained for the waiver price by the Bucs in 1977. Linebacker Richard Wood was drafted No. 3 by the New York Jets in 1975 and Tampa Bay obtained him for a No. 7 pick in 1976.

The Bucs were criticized for trading nose tackle Dave Pear, who made the Pro Bowl last season, to Oakland for No. 2 and No. 3 draft picks.

But Tampa Bay got guard Greg Roberts of Oklahoma, who runs the 40-yard dash in 4.7 seconds, with the No. 2 pick and reserve running back Rick Berns of Nebraska with the No. 3 choice.

Even more controversial was Tampa Bay's trade of a No. 1 pick for defensive and Wally Chambers of the Bears, who then suffered a serious knee injury, Chambers if now a regular starter, but the Bears used the No. 1 pick for defensive lineman Dan Hampson.

The Dolphins have a decision of their own awaiting final judgment. They waived Garo Yepremian, who had kicked 16 straight field goals, who kept rookie Uwe von Schamann. He missed two field goals on Sunday in three attempts, while Yepremian set a NFL record with an 18-yard field goal for New Orleans, his 17th straight.

The Buccaneers may be on their way to a more important goal -- unifying the Tampa Bay community. The St. Petersburg Times points out that the Bucs are the most predominantly black team in the NFL, with 15 of 22 starters and 28 of 45 on the roster; yet most of the fans are white.