The season is open!

Yesterday morning co-instructors Rami and Arto and myself had gathered most of our paragliding students at Nummela airfield. Very early in the year for us to be at an airfield. After an usual warm and sunny week practically all snow was gone and the field was dry. Only 2 weeks ago we were towing from the frozen lakes!
The prediction was for sunny and calm weather and we hoped to please all students with many flights. Once we started there was a bit more wind than we'd expected but not too bad. And up till noon we towed all students several times. Just when we were all getting hungry some students clearly floated in some thermal bubbles and stayed up for short periods. Likewise the erratic winds at our start indicated increasing thermal activity. Rami decided to check out the weather and stayed up easily. Then Arto towed me up and there were thermals everywhere. In fact surprisingly strong ones. In no time I hit the local airspace ceiling of 2500 MSL.
It was very easy to see the thick air laying above the greater Helsinki region. The air quality in recent days has been very poor, due to road dust (from the use of studded tires), fine soot (from fields burning in neighboring Russia) and pollen.
I glided a bit around the airfield and always found new thermals, at best a consistent 4 m/s up, with peaks of 5 m/s. As usual in spring the thermals were small and stingy, with strong sink adjacent to the thermals in narrow bands. After some 45 minutes I was really hungry and decided to go down. The lower 100 m above the airfield were quite turbulent now, and my rock ' roll in the landing approach convinced our students that we could not tow them now.
An hour later we instructors did some more flying and there was still plenty of thermal activity. But now with stronger winds and weaker thermals, so much more drifting.
After 3 pm I had to leave but Rami reported that later the winds calmed down and they continued to tow students, in the end some 50 flights were made.