The 2011-12 TV season officially ended last week, leaving the broadcast schedule simultaneously overfamiliar and unrecognizable. Overfamiliar, because if a show is in the same time slot it's occupied for the last eight months, it's bound to be in reruns. Unrecognizable, because the network lineups are suddenly full of reality competitions, Canadian imports and sports.

If you want to see new scripted television, the cable networks are the place to go: In the coming weeks, buzzy new series like HBO's "The Newsroom" (Aaron Sorkin!), USA's "Political Animals" (Sigourney Weaver!), ABC "Family's Bunheads" (Amy Sherman-Paladino!), and FX's "Anger Management" (Charlie Sheen!) will debut alongside returning favorites such as "Breaking Bad," "True Blood" and "Louie."

Why have the broadcast networks never truly embraced summer? Americans, especially the young ones advertisers most want to reach, spend more time away from their televisions when the nights are light, the weather is warm and the kids are on vacation, so TV advertising is at its cheapest. With less money coming in, the networks abandon pricey original dramas in favor of budget programming: dating games, talent shows and cops in oddly nonspecific North American cities talking aboot catching criminals.

If June, July and August are of any use to the big six networks, it's as a period of experimentation — many staples of the regular broadcast season, especially reality mega-hits like "American Idol," "Survivor" and "Dancing With the Stars," got their first trial airings in summer. These months can also provide a second chance for sitcoms. Vacations and outdoorsy activities, which keep people away from their TVs, mean that heavily serialized dramas fare poorly, but sampling-friendly comedies can thrive. Onetime NBC chief Warren Littlefield's new book "Top of the Rock: Inside the Rise and Fall of Must See TV" reveals that "Cheers" and "Friends" blossomed in summer reruns, and more recently ABC's "Happy Endings" found its audience in second, warm-weather showings.

With the broadcast cats away, the cable mice will play. Ted Linhart, senior vice president of research at USA Network, which has ruled the cable ratings for six straight years, told me that the relative quiet of broadcast-network schedules in the summer months means that "a large magnet of viewers is turned off." It's no coincidence, then, that most cable hits are launched when there's no R in the month. "The summer break from broadcast gives cable networks an opportunity to get people hooked," Linhart said.

And what kinds of shows do summer viewers latch onto? Just as we reach for lemonade rather than hot chocolate when the weather turns warm, light, bright shows appeal more than the dark, tense dramas of the main broadcast season. USA series like "Burn Notice," set in Miami, and "Royal Pains," in the Hamptons, are all sun, swimsuits and seersucker. The heroes are smiling and stylish — "White Collar's" Neal Caffrey and "Suits' " Harvey Specter are the best-dressed men this side of Sterling Cooper Draper Pryce — and they're always surrounded by a loyal coterie of friends and family. They're exceptionally good at their jobs, sometimes freakishly so — "Suits' " Mike Ross has a magnificent memory that allows him to find the tiniest flaws in arcane legal documents after a quick perusal, while "Covert Affairs' " CIA agent Annie Walker has to do little more than pass through customs to pick up the local language — and best of all, you can miss an occasional episode and still know exactly what's going on.

This summer will be a little different, since at least one broadcast network is guaranteed a ratings smash between July 27 and Aug. 12. NBC paid a whopping $1.18 billion for the right to broadcast the London Olympics and will spend untold millions more crafting sob stories about the athletes. NBC lost $223 million on the 2010 Vancouver Games, but there are no eight-gold-medal swimmers or plucky pixie gymnasts in the Winter Olympics. The Summer Games are typically a ratings juggernaut — the 2008 Opening Ceremony was seen by nearly 35 million U.S. viewers — and the 17 nights of prime-time telecasts will provide a great promotional showcase for NBC's fall programming. After all, Americans tend to watch live — who wants to discuss swimming events when the action has moved to the track? — which means that unlike during most shows these days, during the Olympics people watch commercials. During the first week of the Beijing Games, telecast ratings saw a DVR jump of just 5 percent, compared with a 41-percent increase for, say, an episode of "Big Brother."

The Games also cause scheduling headaches for the cablers. As USA's Linhart told me, when a network has a slate of hit shows running in the summer, it's tough to shut everything down for a sporting event, and it's even harder to bring the audience back when it's over. USA, which is part of NBCUniversal, hasn't yet announced its Olympic plans, but back when USA broadcast U.S. Open tennis, Linhart says, "We had to take a break of two or three weeks, and we would see that the numbers for the next [episode after the hiatus] would be low, because people weren't really aware that the show was back."

Apart from the Olympics, there are other signs that summer habits might be changing. According to the Los Angeles Times, 58 percent of U.S. homes watched prime-time television in August 2011, up from 56 percent in August 2009. Some of the change is surely driven by all that new cable content, but there is a technological component, too. Patricia McDonough, senior vice president of planning policy and analysis at Nielsen, told me that increasing adoption of DVRs — about half of U.S. households now have one — means the summer ratings dip is less pronounced than in the past: "At 8 o'clock we may still be outdoors, but by 9 or 10, we may be in and watching programming. Now we don't have to miss our favorite show if it's on at 8, because we can DVR it and watch it when we get back."

And it's not just DVRs. TV catch-up service Hulu has announced 10 original or exclusive programs that will unspool over the summer. What's more, as of 2012, most mobile phones are smartphones, which means viewers can take their TV habits beyond the living room. "If I'm out in the backyard barbecuing, I can still be watching the ball game. So the television is going with us this year probably more than ever before, and that's a trend that will continue," says McDonough. Right now, TV networks can't sell advertising against that al fresco viewing, because it doesn't show up in the standard Nielsen ratings, but the company has recently established a smartphone panel and other cross-platform measurements, so that may soon change.

Although this is the only time of year that's seeing increased viewership, there's still no incentive for the networks to invest in summer dramas, at least not until the young audience grows significantly, bringing with it increased ad revenues. Until then, USA and TNT — home of "The Closer," "Leverage" and "Rizzoli & Isles" — are there to satisfy viewers' cravings for characters. But don't weep for the broadcast networks. They're putting the warm weather to good use: Five of last season's 10 most-popular shows were reality contests that got their start in the summer months.