Explanation of the readings
Notes on time, measured variables and units
Time
Time plays an important role in continuous measurements. The measured values are related to each other via the measurement points in time. Observed values at a certain point in time are often compared with other measurements or are processed. However, this is only possible if the recorded measurement times do not have large errors. For this reason, the clock in the data acquisition system at the weather station is synchronized using NTP, which keeps the time error well below one second.
Another important requirement is that the time series (if possible) has no gaps and that no point in time occurs more than once. However, these two cases occur when the measuring time is linked to the official time. When switching to summer time, there is a gap of one hour and at the end of summer time the hour between 2 and 3 o'clock occurs twice. Such a behavior of the measuring time makes the evaluation of the data considerably more difficult, which is why no summer time changeover is made when recording the time for the meteorological measurements. Here, the time is given as Central European Time (CET).
The current measured values shown in the first table are taken from the continuous measurements of the meteorological station. They are transferred to this weather page a few minutes after every ten minutes. Under certain circumstances, incorrect values may be displayed temporarily, e.g. if maintenance work is being carried out on the measuring system. Further information on the measured values can be found in the following table:
Measured quantity | Rounding | Measuring height | Unit | |
|---|---|---|---|---|
Air pressure | 10-min average | none | 2 m (92 a.s.l) | hPa |
Temperature | 10-min average | none | 2 m | °C |
Relative humidity | 10-min average | none | 2 m | % |
Wind speed | 10-min average | none | 30 m | m/s |
Wind direction | 10-min average | 5 degree | 30 m | degree |
Precipitation | 10-min sum | none | 1 m | mm |
As the surrounding forest has a height of around 20 m, the wind direction and wind speed are measured at a height of 30 m. The wind direction is given in degrees and the wind speed in m/s on the weather page. The number of degrees indicates the direction from which the wind is blowing. Here, 0 degrees means wind from the north, 90 degrees corresponds to an easterly wind, etc. The wind speed can be converted into other units using the following table:
Beaufort | km/h | m/s | kn | Description |
|---|---|---|---|---|
0 | 1 | 0 - 0,2 | 0 - 0,4 | Calm |
1 | 1 - 5 | 0,3 - 1,5 | 0,5 - 2,9 | Light air |
2 | 6 - 11 | 1,6 - 3,3 | 3,0 - 6,4 | Light breeze |
3 | 12 - 19 | 3,4 - 5,4 | 6,5 - 10,5 | Gentle breeze |
4 | 20 - 28 | 5,5 - 7,9 | 10,6 - 15,4 | Moderate breeze |
5 | 29 - 38 | 8,0 - 10,7 | 15,5 - 20,8 | Fresh breeze |
6 | 39 - 49 | 10,8 - 13,8 | 20,9 - 26,8 | Strong breeze |
7 | 50 - 61 | 13,9 - 17,1 | 26,9 - 33,2 | |
8 | 62 - 74 | 17,2 - 20,7 | 33,3 - 40,2 | Gale, fresh gale |
9 | 75 - 88 | 20,8 - 24,4 | 40,3 - 47,4 | Strong/severe gale |
10 | 89 - 102 | 24,5 - 28,4 | 47,5 - 55,2 | Storm, whole gale |
11 | 103 - 117 | 28,5 - 32,6 | 55,3 - 63,4 | Violent storm |
12 | 118 - 133 | 32,7 - 36,9 | 63,5 - 71,7 | Hurricane-force |
Climate values
The table of climate values contains significant measured values from the previous day and night. The period for determining the temperature minimum was chosen so that in most cases the minimum occurred during the previous night. In the case of strong warming during the previous day - e.g. due to advection of warm air from the south - and slight cooling during the following night, the minimum may also have occurred in the morning of the previous day.