Wallis and Futuna weather by month

In Mata-Utu, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around April 23 and lasts for 5.8 months, ending around October 17. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 67% of the time on average.

The cloudier part of the year begins around October 18 and lasts for 6.1 months, ending around April 22. The cloudiest month is January, when it is overcast or mostly cloudy 76% of the time.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Mata-Utu is typically breezy, near 21 km/h, and varies moderately with the seasons.

The windier part of the year lasts 5.2 months, from around May 18 to Oct 22. The windiest month is July, averaging about 26 km/h (breezy).

The calmer part of the year runs from around Oct 23 to May 17, with March the calmest month at about 17 km/h.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Mata-Utu receives about 5.4 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.3 and 6.1 kWh/m².

The brighter stretch of the year lasts 7.2 months, from around Aug 27 to Apr 1. The brightest month is December, averaging about 6.0 kWh/m² (bright).

The dimmest month is June, down near 4.3 kWh/m² — roughly 28% less than the December peak.