Will the heat and sunshine last for Glastonbury?

It’s now less than a week until Glastonbury opens with the full festival running from Wednesday 25th until Sunday 29th June. The temperature in Somerset on Thursday 19th was 28C, but will the heat and sunshine last? It’s vital for packing purposes, but it would be bold not to take your wellies to Glastonbury. Do take sunscreen.

So far this month for nearby Yeovil- rising temperatures and spells of dry weather (Netweather Radar Extra)

The weather is going to go through a change back to a fresher, not as hot phase, with breezy conditions off the Atlantic. However, late next week high pressure will nose back over southern Britain and settle the weather down whilst keeping any frontal rain and low pressures away to the north. It looks like there will be warmer air moving up through the UK by Friday and lasting into the weekend. Perhaps like this week, the heat then fades at some point on Sunday.

Local  temperature observations showing 28+ Celsius on Thursday 19th June as part of Netweather Radar

 If Saturday does bring some very warm air, there could also be a scattering of heavy even thundery showers. At this range, there is nothing to say that they will affect Worthy Farm but it could be something to watch out for. With only light winds, if a heavy shower does pass by, it could bring a hefty downpour and create big puddles. However, it is a low risk at this stage.

Lineup for Glastonbury 2025

Problematic weather would be strong, gusty winds and thunderstorms. Heavy and persistent rain causes the mudbath conditions, which some years at Glastonbury are famous for. At this stage, due to the lengthy, dry and warm spring, there shouldn't be big problems with deep mud but conversely, it can be that in a heavy downpour, the water can just remain on the surface. 

Temperatures could start around 17 to 19C but rise on Saturday to 22C. Currently, this is not the same setup as for the end of this week with intense lingering heat but it will still feel warm in the strong sunshine. However, in the evenings and overnight, it will feel cooler and fresher, so consider that whilst we swelter in this current heat.

A showery unsettled picture on the ECM model with a brisk westerly flow midweek

The uncertainty in the forecast is when the high will build northwards, which would protect Somerset from the incoming Atlantic frontal rain and showers.

More settled on the ECM model by Friday as the high pressure builds from the south

 This in turn could allow more heat to build day on day if there was more sunshine, dry weather and lighter winds. So by Saturday it could be nearer to 26C and will feel very warm. 

Overall, the midweek start could be a bit unsettled. It seems that the outlook for Glastonbury always starts with a showery westerly flow. The middle part of the festival should be fine, with a lot of warm, sunny and fair weather. The cloud cover will vary. Then towards the end, there could be some heavy showers on Saturday but a low risk at the moment. There is also uncertainty around Sunday, if the weather begins to change or that change gets delayed. 

More Glasto weather discussion in the Netweather community forum