Every month, UrbanVolt publishes a solar generation update for our clients across the UK and Ireland, so you always know how the weather has affected your system’s output.
United Kingdom
July 2026 was one of the best months for solar generation the UK has seen in recorded history.
The UK recorded 258.7 irradiance hours against a long-term average of around 173 – 149% of normal, with records going back to 1919. England, Wales, Scotland and Northern Ireland all came in well above average. Scotland recorded 178.6 hours (127% of average) and Northern Ireland 194.2 hours (143%), while England (156%) and Wales (174%) pushed even higher. For most of the country, it was simply the sunniest July on record.
High pressure sat over or very close to the UK for almost the entire month. The jet stream was displaced well to the north, which meant the Atlantic weather systems that normally drag cloud and rain across the country couldn’t get a look in. The result was nearly four weeks of predominantly clear skies, strong sunshine and very little rain across England and Wales in particular.
A brief interruption came around 18th July when the high drifted west and a cooler northwesterly airflow brought cloud and some rain to Scotland and northern England – the first time since 5th July that temperatures in the south had failed to hit 30°C. Temperatures climbed again through the final ten days of the month, with southern England regularly back into the high 20s and some locations again exceeding 30°C.
On the rainfall side, England recorded just 6.5mm for the entire month – 10% of its long-term average and its driest July in 191 years of records. Wales managed just 9.3mm, also its driest July on record. Nineteen counties, including Berkshire and Surrey, recorded less than 1mm of rain across the whole month. The UK overall came in at just 35% of average, the third driest July on record. By the end of the month, official drought conditions had been declared across the whole of Wales and around half of England, with Thames Water and Southwest Water both introducing hosepipe bans.
For solar generation, virtually no rain means virtually no cloud, and that is what the irradiance data shows. The combination of record sunshine hours, consistently above-average temperatures and day after day of unbroken high pressure delivered the kind of monthly generation total that most UK systems have not seen before in a single July.
If you’re reviewing your monitoring data in the UrbanVolt Portal, July should be the standout month of the year so far, and quite possibly the best single month your system has recorded. August will tell us whether these extraordinary conditions will persist.
Source: https://www.metoffice.gov.uk/research/climate/maps-and-data/summaries
Ireland
Similarly, July 2026 was one of the best months for solar generation the Ireland has seen in recorded history.
Johnstown Castle in Co Wexford provisionally broke the national record for the sunniest month ever measured in Ireland with 332.4 hours of irradiance, beating the previous record of 308.2 hours set at Valentia in July 1955. Cork Airport came in at 315.1 hours, also surpassing that previous record. Every single station in the country recorded irradiance totals above their long-term average, and the national rainfall total of just 16mm was the driest July in Irish records.
High pressure was the story of the month. It sat over or very close to Ireland for almost the entire July, keeping Atlantic weather fronts pushed out to the north and west. Any fronts that did make it through brought some cloud and rain mainly to the northwest and west, but the south, midlands and east stayed largely untouched. The result was week after week of clear skies, strong sunshine and almost no rain across most of the country.
The irradiance figures are hard to overstate. Percentage of long-term average ranged from 172% at Casement Aerodrome in Co Dublin (264.0 hours – its sunniest July on record) to 183% at Shannon Airport (247.7 hours – its sunniest July since 1955). Even Malin Head at the tip of Donegal, which was closer to the Atlantic fronts and in the path of whatever cloud did move through, still recorded 133.7 hours. For systems across the midlands, south and east, July generation totals will be highest they’ve been for many years.
Rainfall nationally was just 16mm – 17% of the long-term average and the driest July on record. At Cork Airport and Moore Park, just 1.1mm fell across the entire month. Johnstown Castle recorded 1.5mm, Oak Park the same. Twenty stations recorded absolute droughts and fifteen stations recorded partial droughts during July, with some of those drought conditions extending into August. For solar generation, essentially no rain means essentially no cloud-bearing weather systems.
The north-west of the country did see more cloud and some rain, particularly in the first and final weeks of the month when Atlantic fronts were able to push further east. If your site is in Connacht or Donegal, July will still have been a very strong month – just not at the same level as sites in Leinster, Munster and the midlands.
If you’re looking at your monitoring data on the UrbanVolt Portal, July should be the standout month and, for many systems, the best single July since installation.
Source: https://www.met.ie/climate-statement-for-july-2026