Het weer in Sayulita (Riviera Nayarit) in december

Regulars call this a favorite month, warm and sunny by day with the air feeling noticeably less oppressive than the rainy summer stretch, evenings cool enough for a light sweater. Our row backs that warm, still-humid read, 29.8C reading as a hot 33C, over 19.4C nights, with rain minimal at 22.3mm across 3 days and humidity at 84 percent, real moisture in the air even if it's a real drop from summer's peak. Regulars are specific this marks the start of the humpback whale season in Banderas Bay, a real seasonal highlight beyond the weather itself. The sea sits at a warm 26.8C, cooling a touch from summer highs but still comfortably swimmable. The record: 9.6 hours of sun, a 7.8 kph wind and AQI 38.

Sayulita's forum draws a real distinction between the two halves of October: the first couple of weeks are still properly rainy season, with high heat, humidity and torrential downpours mostly overnight, while the back half of the month sees the heavy rain largely wind down even though it's still genuinely hot and humid. Posters pointed to late October into early November as a real sweet spot, once the worst of the humidity has broken. Warm, swimmable ocean water year-round is a constant regardless of which half of the month you catch.

Forum posters describe early April as one of the driest, most pleasant stretches of the year - mid-80sF days, mid-to-low-60sF nights, with no rain since the previous October and mosquito numbers correspondingly at their lowest. A cooling ocean breeze in the afternoon means posters recommend packing a light sweatshirt or pants even on an otherwise hot day. Posters contrast April favorably with February, noting shorts and short sleeves work fine in April versus needing light long sleeves and trousers earlier in the dry season. The one clear scheduling warning: Sayulita gets genuinely overwhelmed with domestic tourists during Semana Santa (Easter Holy Week), and posters consistently suggest avoiding that specific week if a quieter April visit is the goal.