January is a fabulous month. The snow is bound to be deep enough now, however late the season began. It squeaks as you walk on it. Powder off-piste lasts for weeks. There's almost nobody around. Holidays are sold for less than they cost. Statistically it is probably a fraction colder than December or February, but a cold sunny day doesn't feel as cold as a warm, cloudy day. And the Alps don't do cold like the Rockies...
February is when all Europe has half term. France spreads its school holidays across four weeks, normally from around 7 February to 7 March. So the beginning of February is empty, because families aren't on holiday, but everyone else thinks they are!
The rest of February is similar to New Year: Val d'Isre feels very full, but the crowds disappear faster than when a busker takes his hat around. You should book ski school if you have kids or beginners, and just avoid that 9.30 slot if you don't. If you want a take-away pizza, you'll have to fight half of Paris for it. If you want gastronomy, there'll be space. The snow is still the crisp, carvy stuff people who only ski at Easter have never known, but you're starting to need serious sun screen.
March is many people's favourite month. The snow is now at its deepest. As the month goes on the lower slopes will be slushy in the afternoons and icy in the mornings, but that's why you've come to a high resort. The upper slopes feel like winter, the sun feels like summer. Anything less than Factor-60 is positively dangerous.
Easter is when you are really glad you picked a high-altitude ski area. The days are long and warm. If you pick your runs carefully, avoiding those which melted the previous afternoon and are still icy, the skiing is brilliant. What's more, April showers in Britain are snow showers at 6,000 feet, and there are more days of fresh powder, than in any other month. Best of all, the continentals are convinced that there's no skiing in the spring, and the slopes are never crowded.
April powder doesn't last long: after one sunny afternoon it starts to transform into the even more exhilarating spring snow. This isn't just snow that happens to be hanging around in spring. It is snow which has melted and re-frozen several times. Once the morning sun has been on it for a while the top layer starts to soften off, and it's like skiing on a billiard table: soft and velvety on top, firm underneath. To find perfect spring snow you may have to walk some distance, take a helicopter, or just hire a guide who has a few secret pitches. But it's worth it.
After the Easter holidays there are two or three weeks of long, warm days of powder or spring snow, winter conditions on the upper slopes and water skiing down low. Not all of the runs will be ready at the same time. Some will have shut for good. It's like November all over again. Wonderful conditions on a limited number of slopes, with no-one around and giveaway prices.
So when's the best time to come? Well, early December always has empty slopes and low prices, and often has fantastic snow; Christmas and New Year offer the best family holidays you'll ever have; the snow and the skiing are best in January, and the days, though short, are mostly sunny; the combination of winter snow and spring sun peaks in February; March has most accumulated snow, an instant suntan and no school holidays; April has everything from powder to picnics, long afternoons, high sun and amazing bargains.
Frankly, it doesn't matter when you come. It's still the best holiday in the world.