From winter to spring in 15 days

The first half of February has been the coldest of the winter, while the second half is being almost spring.

Air temperatures in the shadow, 5 cm above the ground. The coldest day was on February the 12th at 7:00 am, with a temperature of  -7,54ºC. At 10 cm depth the water was at  1,08ºC , at 50 cm 4,09ºC.

Water temperature at 10 cm depth



Water temperature at 50 cm depth. In the coldest days, in the bottom of the pond the temperatures were lower than 4ºC, they reached 3.59ºC.  It wouldn't have happened if the pond was deeper.

Last day I posted pictures of the turtles swimming under the ice in the morning. The data logger temperatures were:

February the 8th  9:00 (half an hour before I saw them)
Air -4,6ºC
Water at 10 cm depth 1,08ºC
Water at  50 cm depth 4,09ºC

February the 10th 9:00
Air -3,07ºC
Water at 10 cm depth 1,08ºC
Water at 50 cm depth 3,59ºC

They were swimming superficially, at less than 10cm depth.

Since the 15th the temperatures have been increasing gradually. This last week there has been a marked temperature contrast between the  day and night, with spring temperatures in the midday.  Now I often see the turtles, sunbathing with half closed eyes, very confident. On Sunday the 26th, around 4:00pm, I saw the male nibbling at the filamentous algae that grow in the pond. I threw an earthworm near him and he ate it. The air temperature was 23,83ºC, water at 10 cm 12,61ºC , water at 50 cm  8,61ºC. 

That day I added water to the pond with the hose. I saw a wall lizard (Podarcis hispanica) approaching by the wall I had sprinkled. It looked as though she felt attraction towards the water. I sprinkled the wall again and she started licking the wet stones. She did it for a long time, maybe it was the first time she drank since hibernation (this has been a very dry winter). The heat, the wall lizards, the turtles moving, the almond tree flowering, the birds singing... I also felt the spring coming.