Published 12.10.2020 Before the onset of the cold period, until September 1, technical observers of weather stations prepare meteorological sites for the autumn-winter season. To measure relative humidity at temperatures below - 10 °C, a hair hygrometer (main and spare) and a hygrograph are installed in the psychrometric booth, for hourly recording of air humidity values. In some cases, in the southern regions, when dry hot weather sets in September, the installation of hygrometers and hygrograph can be postponed to a later date. However, before the beginning of October, air humidity meters must already be installed in the booth and start comparative observations on the psychrometer and hygrometers (hygrograph). A schedule is drawn up based on comparative observations for a certain period (until October 15), which makes it possible to draw a conclusion about the quality of the device and its suitability for operation. The period from October 16 to November 15 is called seasonal, and the corrections derived from this schedule are used throughout the winter.
Starting from September 1, snow measuring rails in the form of an equilateral triangle should be installed on the meteorological site to make observations of the height of the snow cover and the wires of an ice machine for observing ice and frost deposits.
In the autumn period, when the soil temperature drops at a depth of 5 cm below 0 °C, Savinov thermometers are removed from the installation at the meteorological site.
When the temperature drops below 15 °C, it is necessary to loosen the tension of the tripwires on the masts of wind measuring devices.
Also, before the onset of the autumn-winter period, weather stations are provided with solid fuel (coal, firewood), and hard-to-reach stations (TDS) are also provided with rations.