Daytime temperatures approaching 90 degrees suggest the heart of summer, not the midpoint of the high school football season.

But as Week 5 of the eight-week regular-season gridiron grind approaches the competition is heating up, too. Even so, little is certain about which teams in the state’s North region will emerge atop their divisions come playoff time as seemingly many more programs than usual remain in position to challenge for postseason berths.

Credit that in part to a changing of the guard in some divisions. Defending Class D state champion Maine Central Institute of Pittsfield is now in Class C while 2016 Class B state champion Brunswick and defending Class A North title holder Portland are both 0-4.

Perhaps of even more significance is a new scheduling format that matches opponents of similar status with each other more often during conference play, along with similarly tiered crossover schedules that provide teams in Classes B, C and D competitive out-of-conference opponents from different regions or classes.

Twenty-four North teams are at .500 or better through four weeks, including the region’s lone unbeaten, Class A Edward Little of Auburn.

Seven teams with 1-3 records also maintain reasonable playoff optimism, given that 26 of the 36 North teams will qualify for the playoffs that begin Oct. 27 and 28.

Here’s a look at the North as summer has turned to fall — at least on the calendar.

Class A (6 playoff teams): Could this be the year a Kennebec Valley Athletic Conference school captures the regional championship in this division for the first time since a fourth class was re-instituted statewide in 2013? Edward Little is undefeated but ranked third in the Heal Points behind 3-1 KVAC rival Lewiston and 3-1 Windham. Windham, from the Southwestern Maine Activities Association, already owns a win over Lewiston and travels to Edward Little on Oct. 13, while 2-2 KVAC entry Oxford Hills of South Paris has the toughest remaining schedule in the division with Windham and Class A South powers Thornton Academy of Saco and Scarborough in the next three weeks. The battle for the top seed could come down to the annual Battle of the Bridge between EL and Lewiston on Oct. 20.

Class B (6): Messalonskee of Oakland has lived up to preseason expectations. Its 3-1 record includes an unbeaten division mark. Brewer (2-2) similarly is undefeated against North foes, its losses coming in crossover tests against Westbrook and Greely of Cumberland Center. Lawrence of Fairfield, Skowhegan and Cony of Augusta also are at .500, with Cony to visit Brewer on Friday night in the BDN Game of the Week. Messalonskee has the toughest remaining schedule among contenders with challenges against Falmouth, Brewer, Cony and Lawrence.

Class C (8): This division boasts no unbeatens but eight teams with either one or two losses, a swarm led by perennial powerhouse Winslow and defending North champion Mount Desert Island of Bar Harbor. Winslow and MDI are Nos. 1-2 in the Heal Points and remain the top bets to emerge from this field after playing a one-point game — Winslow winning 21-20 — in their season opener. Oceanside of Rockland-Thomaston and MCI (both 2-2) represent the next tier, but Class C North also may best reflect the impact of the new schedule format and the most recent biennial reclassification. Nokomis, winless in Class B the last two seasons, is 3-1 while Waterville, winless in C in 2016, and John Bapst of Bangor, 1-7 each of the last two years, are both 2-2. And Hermon, 3-21 over the last three seasons, already has matched that win total in four weeks.

Class D (6): Foxcroft Academy, down from Class C by enrollment this year, is 3-1 after achieving favorite’s status in the LTC with a 45-18 win over Bucksport last weekend. While Bucksport is just 1-3, its other losses came in crossover games against defending Class D South title holder Lisbon-Saint Dominic and reigning Class C North champ MDI — which are a combined 7-1. Dexter-Piscataquis (3-1) is fresh from a trip to the 2016 North final, and Washington Academy of East Machias (3-1) is off to its best start in program history. Mattanawcook Academy of Lincoln, one of three teams at 2-2 along with Houlton-Hodgdon-Greater Houlton Christian Academy and Mount View of Thorndike, remains a darkhorse threat in light of its triple-overtime loss to Bucksport.

What offers less reason for optimism throughout the North in pursuit of the ultimate goal — a state championship — is how the region has fared against the South so far this season, particularly in head-to-head clashes involving favorites in the respective divisions.

In Class A, Windham’s only loss was a 55-7 decision at defending state champion Bonny Eagle of Standish. In Class B, the only blemish on Messalonskee’s record is a 32-7 loss to reigning Class B South champion Kennebunk at Oakland.

None of the Class C North leaders has faced a C South opponent yet. On Oct. 13, undefeated South top seed Leavitt of Turner Center visits MDI.

In Class D, both Foxcroft Academy and Bucksport dropped season-opening crossover games to South contenders, Foxcroft a 49-28 loss to 3-1 Madison-Carrabec and Bucksport a 36-13 decision at Lisbon-Saint Dominic.

The North is 3-17 against the South so far this year.

Ernie Clark

Ernie Clark is a veteran sportswriter who has worked with the Bangor Daily News for more than a decade. A four-time Maine Sportswriter of the Year as selected by the National Sportscasters and Sportswriters...