Norfolk Island weather by month

In Kingston, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.

The clearer part of the year begins around June 22 and lasts for 4.9 months, ending around November 17. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 71% of the time on average.

The cloudier part of the year begins around November 18 and lasts for 1.8 months, ending around January 12. The cloudiest month is December, when it is overcast or mostly cloudy 46% 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 Kingston is typically breezy, near 25 km/h, and varies moderately with the seasons.

The windier part of the year lasts 4.8 months, from around Apr 23 to Sep 14. The windiest month is July, averaging about 27 km/h (breezy).

The calmer part of the year runs from around Sep 15 to Jan 27, with December the calmest month at about 22 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.

Kingston receives about 5.0 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 2.7 and 7.2 kWh/m².

The brighter stretch of the year lasts 6.2 months, from around Sep 16 to Mar 23. The brightest month is December, averaging about 7.1 kWh/m² (intense).

The dimmest month is June, down near 2.7 kWh/m² — roughly 61% less than the December peak.