San Andrés — sää kuukausittain

The weather is not the thing regulars warn about for January here - they take it as good and move on. The crowd is: this island is packed until about the 15th, because the end of December through January is when Colombians and much of South America take their annual holidays, and prices follow. Arriving from about the 15th gets the same month at a different price. Our row fills in what they skip. The trade wind is the defining feature at 30.7 kph, which is why 29.7C reads as only 32C at 81 percent humidity, and the rain is frequent but slight - 66.3mm across 16.5 days, four millimetres apiece. The record: 25.2C nights, 10.4 hours of sun and a 27.6C sea.

February is a good month here and regulars put it plainly: on this coast dry season means windy season. Our row's 30.8 kph is that. The trade-off is one most people do not expect - visibility underwater is often better during the rains, because the wind that comes with the dry months puts a chop on the water. Our 10.7 precipitation days over 25.8mm needs the local gloss too: rain here arrives several times a day and then the sun returns, sometimes a light shower and sometimes a downpour, and it is always warm rain rather than cold. So the day is not lost, just interrupted. The record: 30C days over 25.2C nights reading as 32C, humidity 80 percent, 10.8 hours of sun and a 27.1C sea.

March is the month San Andres regulars name for the combination rather than for any one thing: fewer people, lower prices, and weather that is fine without being punishing - April, they say, is hotter and sunnier than this. It sits inside the island's dry stretch, which our row supports with 7.7 precipitation days carrying only 20.1mm between them. What the row adds is the trade wind at 27.6 kph, which is most of the reason a 30.4C day at 80 percent humidity is comfortable at all. The squalls that bring days of wind and rain to these islands belong to November, not to March. The record: 25.8C nights, 11 hours of sun and a 27.2C sea.

San Andrés's forum calls April hot and sunny, though high season with more tourists and higher prices than the quieter shoulder months. Regulars are consistent that the typical pattern is sunny mornings turning to cloud or rain in the afternoon, and flag the island's weather as genuinely hard to forecast given its exposure to El Niño/La Niña swings — March is often cited as the calmer, cheaper alternative with similarly good weather.

Regulars are specific this counts as shoulder season here, the rain genuinely starting up this month, short periods of it arriving almost daily though typically clearing again within a few minutes rather than settling in for the day. Our row backs that hot, genuinely wet read, 31.4C reading as a scorching 36C, over 26.7C nights feeling 30C, with a substantial 137.9mm of rain across 20 days and humidity at 84 percent. Regulars are consistent daytime temperatures commonly cited in the mid-80s to low-90s Fahrenheit, with hurricane season itself not beginning in earnest until later in the year, running through November 30th. The sea sits at a bath-warm 29.1C. The record: 10.4 hours of sun, a 25.6 kph wind and AQI 50.

Forum posters are direct that October is statistically the rainiest month of the year here, but consistently push back on treating that as a reason to skip it - rain typically falls for just a few minutes at a time rather than settling in for the day, and showers are often isolated enough that it can be raining out at sea while the island itself stays dry, or vice versa. Posters describe the island as hot regardless of when you visit, so October's rain risk doesn't come with a temperature tradeoff. One specific upside posters mention: water visibility can actually improve during the rainier season since calmer seas (less wave action) mean less stirred-up sediment. Posters generally recommend going ahead and booking October rather than avoiding it purely based on rainfall statistics.

December is the tail of the rainy season here and regulars describe it as unpredictable rather than wet - plenty of sun with short rain bursts, some of it around Christmas and New Year, easing as the month goes on. Our row carries the tail end of that pattern at 124.9mm across 22.8 days, still the island's rainiest column of the ones we have. What actually matters for a visitor is the water clarity rather than the rain itself: the sea stays churned from the season's accumulated rain and will not match the crystal water of February through April, even on a sunny day. This is also peak Colombian holiday season, mid-December through mid-January, when the island fills and prices rise well before New Year. Air is 30.2C reading as 33C at a real 31.2 kph wind, the sea 28.5C. The record: humidity 83 percent, 10.2 hours of sun and AQI 44.