Apia month by month, at a glance
Hover each month for the summary. Click to pin it.
Apia receives some 3,090 millimetres of rain a year spread over 173 days, and its driest month, August, still leaves 112 millimetres across nearly ten rainy days. On those numbers, calling the quiet half of the year a 'dry season' is generous. What really separates one half of the year from the other is not the rain gauge: it is that from November to April there are cyclones and the rest of the time there are not.
01 A season with official dates
The South Pacific cyclone season officially runs from 1 November to 30 April. This is not a vague convention: it is the window in which the region's meteorological services switch on their watch and number the systems.
Samoa sits inside that window and remembers what it means. Cyclone Evan, in December 2012, was the worst to affect the country since Val in 1991, with gusts up to 210 kilometres per hour; across the region it left fourteen dead and damage above 315 million dollars.
The odds of meeting one on a particular trip are low, but the practical consequence is not trivial: in those months take insurance that covers cancellations, and do not chain flights or ferries without slack.
Key moments at a glance
112 mm, 9.9 rain days and the year's sunshine maximum.
133 mm and 213 hours of sunshine, with the mildest highs.
483 mm, more than four times August's figure.
414 mm and the middle of cyclone season.
02 Four times more water in January than in August
The contrast between the two blocks is enormous. January leaves 482.8 millimetres and December 413.7; August stops at 112.3 and July at 132.8. That is more than a fourfold difference between the wettest and the driest month.
Rain days run from 20.5 in January to 9.9 in August, out of an annual total of 173. Put another way: even in the best month of the year it rains one day in three, though almost always in showers that leave room for the sun.
May is the most deceptive month. At 244.6 millimetres it rains even slightly more than in April, but it is already outside cyclone season, so it is a reasonable bet if the calendar will not stretch to June.
03 The sun moves opposite to the rain
Apia gathers 2,230 hours of sunshine a year, and the distribution follows exactly the inverse pattern to the water: August leads with 219 hours, July adds 213 and September 207, while January stops at 149 and December at 154.
Between the sunniest and the darkest month there are seventy hours of difference, more than two hours of sun a day. That counts for a lot in a destination where much of the plan involves getting into water.
Temperature, by contrast, adds nothing to the decision. Average highs run from 29.8 degrees in July and August to 31.1 in April, and lows from 23.4 to 24.6. Twelve practically identical months.
04 The river, which also counts
There is a local factor the tables do not show: the city is built in a low, flood-prone valley at the mouth of the Vaisigano, and floods are common in the wet season.
That affects concrete things: closed roads, muddy access to the inland waterfalls and springs, and outings that drop off the plan without warning. In the dry stretch, those same tracks are firm.
The sea follows the same calendar. Between May and October the steadier south-east trade dominates and the northern lagoon is sheltered by the reef; in the wet season there is more swell and worse underwater visibility.
05 What to pack, and in short
Light quick-drying clothes, a thin rain shell, shoes that survive being wet and grip rock and roots, high sun protection, repellent and a dry bag. For villages, something to cover your legs: short clothing is not worn away from the beach.
In short: June to September, with August the best month; May and October work well and sit outside cyclone season; November to April it rains far more and the risk has to be factored in. Here you do not pick a month without rain, you pick a month without a weather warning.
