No, it's not the temperature, but the largest number of degrees the sun can be under the horizon for it to be a light summer night.
Sjælland, May 2008
Martin Joergensen
17 degrees
Since you got this far …
The GFF money box
… I have a small favor to ask.
Long story short
Support the Global FlyFisher through several different channels, including PayPal.
Long story longer
The Global FlyFisher has been online since the mid-90's and has been free to access for everybody since day one – and will stay free for as long as I run it.
But that doesn't mean that it's free to run.
It costs money to drive a large site like this.
See more details about what you can do to help in this blog post.