https://openweathermap.desk.com/customer/portal/questions/16790933-rain-parameter-not-showing-up-
Rain item is showing “1h” in the case when data are received from weather stations directly.
The fact is that some METAR stations do not have precipitation indicators or do not measure precipitation conditions due to some other technical reasons.
In this case, we use model data. So, rain item is showing “3h” when our system returns an API response based on model data.