The given forecast for the temperature is to be understood as follows:
The temperature "DAY" is the most likely temperature in the centre of the relevant region at 3 p.m. on the given day
The temperature "NIGHT" is the most likely temperature in the centre of the relelvant region at 12 p.m. (midnight) on the given day
The resolution of the temperature forecast is 1°C. The indicated range is -21°C to +40°C. If the forecast exceeds this range, the two indicators > and < will be shown, i.e. < -21°C or >40°C.