Weather in San Sebastián, Peru: What to Expect by Season

San Sebastián sits in the Peruvian Andes, where the climate shifts noticeably between wet and dry periods. From November to March, the town sees frequent rain, with January and December bringing the heaviest downpours. The air stays mild, rarely straying far from 13–14 °C during the day, though nights can feel chilly.

The dry season runs from April to September, offering clearer skies and cooler nights. June and July are the driest months, with rainfall dropping to just a few millimeters. This stretch is often the most comfortable for exploring San Sebastián, though mornings can dip below 2 °C—a sharp contrast to the daytime warmth.

Temperatures in San Sebastián remain steady through much of the year, with daytime highs hovering around 20–22 °C. The warmest months are August and September, when the mercury occasionally reaches 21.9 °C. Even in the cooler dry season, afternoons stay pleasant, though the drop after sunset is noticeable.

Nighttime brings a sharper chill, especially from May to August, when lows fall to 1.4–3.8 °C. June and July are the coldest, with temperatures sometimes dipping below freezing. If you’re visiting San Sebastián during these months, layers are key—mornings start cold, but afternoons warm up quickly under the Andean sun.

Rain defines the rhythm of San Sebastián’s year. The wettest months, January and December, see over 150 mm of rain each, often in steady showers rather than storms. February and March are also damp, though slightly less intense, with around 130–155 mm of precipitation.

The dry season from April to September is almost rain-free, with June and July recording just 5–7 mm of rainfall. Even May and August stay dry, making this the best window for outdoor activities in San Sebastián. By October, the rains begin to return, gradually building toward the wetter months ahead.

For a trip to San Sebastián in the wet season (November to March), waterproof gear is essential. A light rain jacket and quick-dry clothing will help you stay comfortable during frequent showers. Daytime temperatures sit around 13–14 °C, so layers—like a fleece or sweater—are useful for cooler moments.

During the dry season (April to September), pack for both warmth and chill. Mornings and evenings can be cold, with temperatures near 1–4 °C, so a warm jacket is a must. By midday, the sun lifts the mercury to 20–22 °C, so lighter layers underneath let you adjust easily. A hat and sunscreen are wise year-round, given the Andean sun’s strength.