Fans of teams on this list will no doubt take offense with the fair-weather label.
And yes, it is exactly what it sounds like.
These fanbases embrace glory, defer hardship and do both with the kind of indifference that infuriates more passionate fan breeds.
My advice for those offended: Don't take it too harsh.
There are worse things than being called a bad fan.
Bad husband, wife, father, daughter, sister, brother, mother and citizen come to mind.
I'm only saying that you, as a collective, display relatively little enthusiasm for professional football.
And on that note, yeah, you kinda suck.
New York Giants: Distracted by the city's many amusements, New York sports fans are notorious for their short attention spans. Want proof? The Giants' 2009 local television ratings were the third worst in the league. Two years after a Super Bowl win, Big Blue was off-Broadway filler.
New England Patriots: Before Tom and Bill arrived, the Pats were a distant fourth in Boston's professional sports pecking order. Today, franchise and owner are feted like regional treasures.
Detroit Lions: The list of excuses is a mile long: bad teams, bad management and an economy so bad even Dirty Harry can't save it. But the fact remains that Detroit couldn't fill one of the nicest, newest stadiums in football during the team's darkest years.
San Francisco 49ers: Welcome back to existence San Francisco 49ers fans! Red-and-gold clad enthusiasts were crawling out of the woodwork during last year's breakout campaign. In in the middle 2000s? Not so much. One of the most successful franchises in league history deserves better.
Philadelphia Eagles: This selection depends on how you define fair weather. In good times and bad, Eagles fans care about their team...a lot. In that sense they are among the league's most loyal flock. But when things turn rotten, they are, in the most delicate terms, quick to anger. In less delicate terms, they're jerks. And I should know, because I'm one of them.
Maybe it's the work of the desert sun, but Cardinals fans seem to have a short memory.
A team that won back-to-back division titles in 2008 and 2009 endured a number of near-blackouts last year, including a particularly close call against the woebegone St. Louis Rams.
Those ongoing attendance struggles indicate that locals have yet to embrace the franchise, even after brief spasms of success.
In all fairness, the franchise hasn't done much to earn the fans' loyalty. Owner Bill Bidwell is a notorious tightwad and the team is 145-239 since moving Phoenix.
Even the most zealous followers needs a little winning for sustenance. And to the fans' credit, local television ratings have remained high since the team's two-year playoff run.
The good news is that the Atlanta Falcons obliterated college rivals Georgia and Georgia Tech in local television ratings last year.
The bad news is that the good news is news at all.
The NFL has been a more popular product than the college game for years now, but in Atlanta it takes an extra ounce of winning to put the pros on a pedestal.
That's life in the South, where college football is religion and everything else is distraction.
Even in cosmopolitan Atlanta, the nation's ninth-largest television market, pro sports have long languished in the shadow of almighty college athletics.
The Falcons have been able to emerge from said shadow on occasion, but only when the on-field product is well above average.
It takes a special kind of fan ennui to lose two NFL franchises, much less in the nation's second largest television market.
No, Al Davis and Georgia Frontiere weren't the most stable NFL owners.
But still, TWO franchises?
Even more amazing, it took 15 years to reach the point where a return feels inevitable.
In the interim, Angelenos got fat on a steady diet of USC football, Lakers domination and perpetual star-gazing. Outcry over the departures was muted and sporadic, especially when compared to that of similarly robbed fans in Cleveland and Baltimore.
Again, we're talking about the second largest television market in America. You would expect widespread outrage, telethons, pandering celebrity appeals.
Instead you got a few sighs and an after-the-fact documentary by Ice Cube.
So while there isn't a Los Angeles fanbase to berate at the moment, the region's prevailing disinterest in professional football earns them an emeritus spot on this list.
Far as I can tell, 2010 was the only year in the past decade where the Carolina Panthers truly stunk
For eight seasons prior the team was either middling, good or excellent—a pretty remarkable run by modern NFL standards.
In that one miserable season, however, support for the team eroded at an astonishing pace.
How bad was it?
So bad that Anheuser-Busch bought 1,200 seats for an early-season home game in order to prevent a local television blackout and ensure that their beer commercials would air.
The "Bud Light bailout," as it is now known, marked a new low for a team that's struggled to outshine NASCAR and college football in the local sports marketplace.
Though Cam Newton rejuvenated interest in the team last year, even Carolina's most ardent supporters question whether the fever can last.
Forever the quintessential baseball town, St. Louis hasn't developed the same enduring affection for its football team.
It seems the Greatest Show on Turf was, as its circus-inspired nickname would suggest, a sideshow attraction for the city's sports fans. And despite that era's overwhelming successes, the Rams have generated little buzz in the years since.
To wit: In 2010, the the Nielsen Company completed a comprehensive study of each franchise's popularity. St. Louis ranked dead last.
A Wall Street Journal article on said study had the following to say about St. Louis' football malaise:
It's not as though the Rams are incapable of being popular. When they reached multiple Super Bowls a decade ago, "everybody in the city loved us," says Hall of Fame-caliber running back Marshall Faulk, who played on those teams.
Though it probably wasn't Faulk's intention, that certainly reads like a swipe at fan loyalty. Coming from one of the greatest player in franchise history, it is an especially damning critique.
When L.A. football crusaders Philip Anschutz and Ed Roski went looking for a franchise to poach, it's no coincidence they targeted the flailing Jacksonville Jaguars. Jacksonville was, and in many ways still is, the wounded gazelle of the football world.
A comically oversized stadium and low population density are partly to blame, but the ongoing attendance woes are also an indicator of the franchise's shallow roots in the community.
No matter how you track fan following—attendance, television ratings, Internet buzz—the Jaguars rank near league's bottom.
With Super Bowl success fading into the rear view, the Bucs have become a remarkably poor draw.
In 2009 they masked the problem by buying back empty seats. Upon dropping that policy in 2010, they lost the full slate of home games to television blackouts.
The most common excuse for Tampa's poor turnout is a struggling local economy.
While I'm sensitive to the hard-times argument, the recent downturn in Tampa-St. Pete isn't anything the long-suffering residents of Cleveland, Pittsburgh and Baltimore haven't seen. And each of those cities boasts a rabid football following.
Tampa seems to be grappling with more than just the housing bubble burst—namely the transient snow birds and college-crazed locals that populate their fickle fanbase.
In the seven seasons from 2004-2010, San Diego made five playoff appearance and never finished below .500. Runs like that don't come along often in the NFL, and they're usually good for some long-term equity with the fans.
Not so in San Diego.
The team was forced to issue 2011's first blackout warning when a pre-season game threatened to draw under capacity.
That was just the start.
The Chargers flirted with blackouts all year and eventually capitulated twice. This from a team that, by Cleveland Brown standards, was damn near elite.
So while crappy teams the league over pad their season-ticket waiting lists, a mildly disappointing Chargers team can't put butts in the seats.
For shame, San Diego. You've earned that impending move to Los Angeles.