Sudden rise in outside temperature at around 5AM

[martinu]

I've noticed that the outside temperature reported by my Davis Vanatage Vue has shown a sharp rise of several degrees C at around 5-6 AM over the space of about 10 minutes for several mornings over the past week. I'm curious what could be causing it. I've not noticed it in previous readings. It seems to correspond with an increase in wind speed from around 0 (average) to around 5 (average): could an increase in wind cause a sudden rise in temperature?

Here are three graphs of a sudden increase:

5 Nov 14




6 Nov 14




10 Nov 14




The 5 Nov one may be caused by the console losing contact with the remote sensor for about an hour, because the temperature and wind speed/direction readings are completely static to the nearest 0.1 degree or 1 mph leading up to the sudden increase. But the 6 and 10 Nov show small random variations leading up to the increase so are not just a stuck reading:

date, time, outside temp, outside hum, etc

06/11/14,05:30,-1.4,97,-1.9,0.0,0.0,0,0.0,0.0,1006.95,676.4,19.5,52,0.0,-1.4,-1.4,0.0,0,0.00,0.00,-3.6,0,0.0,245,0.0,0.0
06/11/14,05:40,-1.3,98,-1.6,0.0,0.0,0,0.0,0.0,1006.95,676.4,19.4,52,0.0,-1.3,-1.3,0.0,0,0.00,0.00,-3.5,0,0.0,245,0.0,0.0
06/11/14,05:50,-0.3,99,-0.4,0.0,2.0,145,0.0,0.0,1006.98,676.4,19.4,52,0.0,-0.3,-0.3,0.0,0,0.00,0.00,-2.3,0,0.0,158,0.0,0.0
06/11/14,06:00,0.8,99,0.7,1.0,3.0,144,0.0,0.0,1006.98,676.4,19.3,52,1.0,0.8,0.8,0.0,0,0.00,0.00,-1.4,0,0.0,126,0.0,0.0
06/11/14,06:10,1.1,99,0.9,1.0,4.0,147,0.0,0.0,1007.05,676.4,19.3,52,2.0,0.6,1.1,0.0,0,0.00,0.00,-1.1,0,0.0,148,0.0,0.0
06/11/14,06:20,1.2,99,1.0,2.0,5.0,150,0.0,0.0,1007.05,676.4,19.2,52,3.0,-0.2,1.2,0.0,0,0.00,0.00,-1.2,0,0.0,174,0.0,0.0

and

10/11/14,04:10,2.4,98,2.2,0.0,0.0,0,0.0,0.2,1001.60,712.8,19.4,54,0.0,2.4,2.4,0.0,0,0.00,0.00,0.7,0,0.0,171,0.0,0.2
10/11/14,04:20,2.3,98,2.0,0.0,0.0,0,0.0,0.2,1001.56,712.8,19.3,54,0.0,2.3,2.3,0.0,0,0.00,0.00,0.6,0,0.0,170,0.0,0.2
10/11/14,04:30,2.4,98,2.1,0.0,0.0,0,0.0,0.2,1001.53,712.8,19.3,54,0.0,2.4,2.4,0.0,0,0.00,0.00,0.7,0,0.0,171,0.0,0.2
10/11/14,04:40,4.2,99,4.1,0.0,2.0,142,0.0,0.2,1001.26,712.8,19.3,54,1.0,4.2,4.2,0.0,0,0.00,0.00,2.9,0,0.0,142,0.0,0.2
10/11/14,04:50,5.2,99,5.0,1.0,3.0,153,0.0,0.2,1001.32,712.8,19.2,54,2.0,5.1,5.2,0.0,0,0.00,0.00,3.8,0,0.0,127,0.0,0.2
10/11/14,05:00,5.3,99,5.1,1.0,6.0,153,0.0,0.2,1001.26,712.8,19.2,54,3.0,4.5,5.3,0.0,0,0.00,0.00,3.9,0,0.0,157,0.0,0.2

[Spider-Vice]

There are a lot of meteorological phenomena that can cause that. It fully depends on those conditions and possibly wind direction, so whenever there is wind, that increase happens. Think of it as a sensible atmosphere, that is cooling down peacefully because there's no air. All of a sudden wind comes from e.g. a mountain and causes some physical effects, warming the air and interrupting the peaceful cooldown, sending the temperature skyrocketing.
There is a similar phenomenon here whenever we have high pressures, winds from the NE at night will increase the temperature by quite a lot.