Ireland weather by month

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

The clearer part of the year begins around October 4 and lasts for 4.1 months, ending around February 5. The clearest month is November, when the sky is clear, mostly clear, or partly cloudy 28% of the time on average.

The cloudier part of the year begins around June 10 and lasts for 3.8 months, ending around October 3. The cloudiest month is July, when it is overcast or mostly cloudy 83% 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 Dublin is typically light breeze, near 16 km/h, and varies moderately with the seasons.

The windier part of the year lasts 5.8 months, from around Oct 5 to Mar 31. The windiest month is January, averaging about 19 km/h (light breeze).

The calmer part of the year runs from around Apr 1 to Oct 4, with July the calmest month at about 14 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.

Dublin receives about 2.9 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 0.5 and 5.3 kWh/m².

The brighter stretch of the year lasts 5.9 months, from around Mar 22 to Sep 17. The brightest month is June, averaging about 5.2 kWh/m² (bright).

The dimmest month is December, down near 0.6 kWh/m² — roughly 89% less than the June peak.