Pond swarming with flies

I have a small garden pond and for the last few very hot days it's had those little mosquito flies literally swarming all over it and all around it. They land on the pavers around the pond, on the stones that form the "beach", and on every other thing in the garden! They walk all over the duckweed and all the pond plants. 
According to google the common Irish mosquito is Culex pipiens so assuming that's what I'm seeing.  
This is the 6th year for the pond and I have never seen so many of them before!