Last few days have been extraordinarily good, clear skies and no cancellations of tours.
But a low pressure area is advancing east towards Iceland, the warm front will come later this afternoon. So most likely there will be no sun tonight.
The picture below shows Harmonie prediction of relative humidity at 925hPa (roughly 700 meter elevation) for 20:00 (8:00PM), July 11th.
As seen here there is a very sharp line from very low humidity to very humid air mass that belongs to the warm front of the low pressure area, which is moving east/north-east from west/south-west.
Current Weather at Gufuskálar Base, 16:00 (4PM)
Wind from south, 172° - 9 meters per second.
Dew Point: 4°C
Precipitation past 24 hours: 0 mm
Possibly we will have to cancel tonight's Midnight Sun Tour. Decision will be made at 18:00 (6PM).
Picture below shows conditions at Gufuskálar Base, 16:30 (4:30PM), looking south.
Extras... The picture below is also captured at 16:30 (4:30PM) at Gufuskálar Base, looking west.
Visibile is the sun at top, then high altitude clouds of cirrostratus and cirrocumulus type. Further down are medium altitude and low clouds that belong to the warm front of the low pressure weather system, visible on the horizon. It's heading our way.
Update at 18:40 (6:40PM)
First low clouds of the front are just arriving right now as seen on the picture below. Expect light showers and poor visibility on Snæfellsjökull tonight.