Late November to early March—summer in the Southern Hemisphere—is considered high season in Patagonia. Demand for accommodations is highest in January and February, so advance reservations are vital. Summer weather in these latitudes is by no means warm, but rather pleasantly cool. Bring an extra layer or two, even when the sun is shining. Windbreakers are essential. On or near these Antarctic waters, stiff breezes can be biting. In spring (September to November) and fall (March to May) the weather is usually delightfully mild, but can also be downright cold, depending on clouds and the wind. The region goes into virtual hibernation in the winter months of June, July, and August.