Vejret i Cancún (Riviera Maya) i december

December is the forum's answer to the sargassum question: seaweed season runs roughly late February to September or October, and from November through February there is little to none — making December one of the cleanest-beach months of the year. Conditions sit around 27°C by day and 24 overnight, with the sea near 27°C too. Rain does show up in the averages, but regulars describe it as overnight or a brief afternoon shower rather than all-day, with the occasional run of two or three drizzly days. The one December-specific pattern: a cold front every ten to fourteen days drops temperatures a few degrees for a couple of days, enough to want long sleeves after dark.

Regulars are consistent this month can turn sunny and hot for a stretch, then briefly cloudy and cool when a cold front passes through, before swinging back to sunny and hot again within a day or two. Our row backs that warm, still-showery read, 27.7C reading as a hot 30C, over 21.5C nights, with 30.1mm of rain across 7.4 days and humidity at 73 percent. Regulars are specific that tropical showers here tend to last only 5-10 minutes rather than settling in, and that packing a light sweater for cooler evenings is worth it even on an otherwise warm trip. The sea sits at a warm, swimmable 26.8C regardless of which version of the day arrives. The record: 9.8 hours of sun, a 20.4 kph wind and AQI 47.

Cancun-forum threads asking about August hurricane season are consistent the odds of an actual storm hitting are low through most of the month, ticking up only toward the very end as the wider season builds toward its September-October peak. A typical day is described as sunny, hot and humid, with forecasts often calling for rain that doesn't necessarily show up - and when it does arrive, it's usually overnight or a brief afternoon burst rather than an all-day washout. Posters call the ocean warm enough to feel almost bath-like, a genuine plus for anyone prioritizing swimming and snorkeling over cooler water. Regulars are consistent that most August trips proceed entirely normally, and recommend simply keeping half an eye on the tropical outlook rather than avoiding the month outright. The record: 31.8C days feeling like a punishing 37C, 25.2C nights, a 28.5C sea and 80 percent humidity.

Cancun-forum threads on September weather confirm it's sunny and hot with high humidity most days, a typical afternoon high around 32C that feels considerably warmer given the moisture in the air. September sits squarely in hurricane season and is one of the two busiest months for tropical activity, but posters are consistent that forecasts calling for rain and storms every day rarely match the actual experience - genuine all-day washouts are called rare, with rain more typically landing overnight or as a brief afternoon burst. Regulars recommend travel insurance covering storms as a sensible precaution, even though the odds of a direct hit on any specific week are described as slim. The clear upside: noticeably lower rates and thinner crowds than the winter high season. The record: 31.3C days feeling like a punishing 37C, 24.8C nights, 175mm across 23.3 days, 82 percent humidity, a 29.9C sea and 10.5 hours of sun.

April in Cancun is dry, hot and squarely inside the worst of the sargassum. Regulars put the peak at April through June, arriving daily and in quantity, varying by the day and by the stretch of beach; their mitigation is geography - it thins going north towards Costa Mujeres, the western shore of Isla Mujeres sees less, and many hotels rake their frontage each morning. Lent can also be very windy here, which our row's 20.9 kph reflects. The other April question is spring break: most American school breaks fall in the last two weeks of March, and the consensus is that Cancun is big enough to dilute them. The record: 29.5C days that feel like 33C, 23.7C nights, 5.7 precipitation days carrying 31.7mm and a 27.2C sea.