MONTREAL -- There are two sides to winter in this French-flavored Canadian city -- the inside and the outside. The outside is cold and snowy, the kind of weather winter sports enthusiasts love. But the inside... ah, that's something else. It's warm and pleasant with only a hint of winter in the city's two dozen or so fine hotels, in its dozens of French, continental and Canadian restaurants and in its rambling underground shopping malls.

The city has put this all together this year in what it calls the Montreal "Snow Ball" -- a unique winter vacation package aimed not only at skiers but at non-skiers and at those to whom the very idea of skiing is an anathema. In fact, it's even aimed at those who don't like to stick their noses outside in cold weather. The idea of Snow Ball is this:

If you like snow, have a ball in it. Go north and play in the Laurentians, head east and slide downhill in the mountains of Quebec's Eastern Townships, or stay in town and glide through the parks on cross-country skis or tromp about on snowshoes. Montreal is made for that.

But if you're a snow and cold-hater, do none of the above. Stay inside. Spend a few days or a week above ground and underground, eating in the gourmet restaurants for which Montreal is noted, strolling along malls, shopping in smart boutiques, attending the theater -- all without ever going outdoors. Montreal is made for that, too.

Snow Ball is a super discount package that includes three days and two nights in a choice of 18 hotels for as little as $42, meal discounts of 15-25 percent (not including wine or liquor) in at least 17 restaurants, ski lift tickets at six areas at discounts of 35-50 percent midweek (15 percent weekends), an 18-mile guided bus tour of the city and 13 free subway rides.

It also includes a Snow Ball ID card good for discounts of 50 percent on transfers between Dorval Airport and downtown hotels, 25 percent on autos rented through Tilden Car Rental Co., 20-30 percent for concert and theater tickets at Place des Arts and for events at the Olympic Stadium and 15 percent on day trips to Quebec City or Ottawa, with further discounts for sightseeing tours in those cities. Some boutiques in shopping malls are also offering discounts to Snow Ball cardholders.

Of the 18 Snow Ball hotels, the basic two nights in the eight that are A-rated cost $52 per person, double occupancy; the $42 figure is for the 10 hotels with B ratings -- but don't sell the B-group short. It's sometimes hard to tell the difference. Additional nights, per person, double occupancy, are $18 at A hotels, $13 at the B's.

Snow Ball has two added inducements this year for Americans, who are its primary targets. One is the favorable rate of exchange, which has been giving them about $115 Canadian for $100 U.S. This amounts to an additional 15 percent discount on everything but the two-night hotel package, which must be paid for in advance in American dollars.

The other enticement, of special interest to ski vacationers, is that the Snow Ball package is available even during Washington's Birthday week.

For skiers, Snow Ball has one major drawback: Montreal is a 45-minute drive from Mont St. Sauveur, the closest Laurentians area, and about an hour's drive from Bromont, the nearest Eastern Township ski center. The driving, however, is easy since virtually the entire route, regardless of the destination, is via superhighway. For those who choose not to rent a car, there is a 50 percent discount on Voyageur buses to and from the slopes.

The Laurentians, where Mont Gabriel briel is also a participating area, offer plenty of carefree, open-slope skiing but with limited challenge.Most Laurentians areas -- including the Snow Ball participants -- offer night skiing and virtually all have snowmaking. And a big Laurentians item is skitouring, for which there are literally hundreds of miles of trails.

In the Eastern Townships, just north of the Vermont border, participating areas besides Bromont include Mont Sutton, Owl's Head and Mont Orford, with vertical drops ranging to 1,600 feet, compared with the 700 or so feet common to the Laurentians. The township areas offer plenty of challenging skiing as well as more modest slopes for beginners and intermediates. Lift tickets in Canada, even without the Snow Ball discounts, are a bargain, topping out at $12 Canadian on weekends and holidays, so skiers need not stick to participating areas.

In the city, there is no fee for use of ski-touring trails in Mont Royal Park, Angrignon Park, the Olympic Basin on Notre Dame Island and other smaller parks.

At Mont Royal, the 764-foot mountain in the center of the city from which Montreal gets its name, there is perhaps the world's least expensive ski lift -- a T-bar that costs 10 cents a ride. The slope isn't much of a challenge out it's fun for beginners. Various other winter sports are offered there and at five other in-town parks; the Olympic Stadium, for example is transformed into a huge skating rink, accommodating 4,000 skaters at a time.

For nonsports types, or the skier who wants to take a day off from the slopes, Montreal offers its dazzling underground city within the city. It's a network of six subterranean shopping plazas that are heated in winter, airconditioned in summer. All are linked either by walkways or by the Metro, as Montrealers call their subway, and most are accessible from the city's major hotels, including the 18 participating in Snow Ball.

Thus, without ever going outdoors, it's possible to visit more than 1,000 shops, three large department stores, 50 major bars and restaurants, plus an even larger number of smaller cafes and bars.

A focal point is the Place Desjardins, a five-tiered, above-and-below-ground center containing the new 600-room Meridien Hotel, more than 100 boutiques and specialty shops and 20 restaurants. From there one can stroll past fountains, plants and sculptures, and cross under St. Catherine Street to Place des Arts, the city's performing arts center, where there are two theaters and a concert hall.

And if a visitor tires of shopping, eating or just browsing, he can take a ride on the Metro.It's an art gallery on rubber-tired wheels. Every subway station is decorated with a giant mural or other art form, some sponsored by banks or other city institutions, some donated by the artists themselves. A subway ride costs 50 cents but Snow Ball purchasers have their free book of 13 tickets, the "lucky 13," good for that number of unlimited Metro rides.

Snow Ball, which runs through April 15, was tested on a limited basis last winter with the avowed goal of proving to off-season tourists that Montreal doesn't hibernate in the winter despite the cold (temperatures average 21.7 degrees Fahrenheit in December, 16 in January, 18.4 in February and 29.5 in March) and the annual 100-plus inches of snow.

The test results were encouraging and Snow Ball is being promoted full tilt for this winter. And the merchants, restaurateurs and innkeepers, after a cautious approach last year, are getting behind the program in increasing numbers. Mayor Jacques Drapeau's aide, whose sole job is to oversee Snow Ball, said he expects the number of participating restaurants to increase substantially over the 17 that were listed on opening day.