March and three snake species?

It is march, the weather predictions are good, sunshine every where! Than you wake up, its cloudy, on our way to the snake hotspot there were also some fogs.. Not really what they predicted.. After a while the first sun comes true and we find several Common lizards. We only hoped to find some Adder, an if the weather was good some grass snakes. After a time we find the hoped Adder, a male that is basking, beautiful hidden in the grass. Some Moor frogs are spotted, but despite no blue moorfrogs.. But the find after that is absolutely amazing! The last Smooth snake that we found in 2011 was on 5 November, the first Smooth snake is on 12 March... We didn't expect that at all! Than the weather changes, the little bit sun that we had in the morning changes for clouds, and we did not see any sunshine for the rest of the day.. Soon after that we also find our first Grass snake of the year! Who did expect that? We hoped on some with good weather, but the fact that there wasn't any good weather.. All the 3 snake species on a moderate day in March.. Climate changes? Some people can spot the snakes on very special methods. Tim was talking to some that walks behind him, and decided to turn and speak face to face, on that moment he spots an Adder! That one was well hidden under the heath. You could only see him from the point of view that Tim had when he turned around! Just before we left the area, because of the bad weather we discover something that might could be an hibernacula. The sun is away for a few hours and within a range of 4 meters we found 3 Adders.. Two where 'basking' together and a lonely beautiful male! That male was a big one! 60 cm of male adder is for Holland quite big! So we closed the day with a score of 5 adders, 1 grass snake and 1 smooth snake, and that for a moderate day in March, it still amazes me!