A few questions related to how select the weather data to show:

Today's forecast

In today's forecast we show data for the current hour (eg. at 11:24 we show data for 11:00). Did we want that, or for the coming hour?

Does not specify what happens at exactly 04:00 - maybe change the implementation so that it is a series of isBefore statements?

DayRow - getWeatherIcon:

If I read the code correctly:

returns undefined if time <= 04:00
Between 04:01 and 06:00 returns symbol for time 04:00, which will not always be present
After 06:01 returns symbol for time 06:00, which will not always be present

Also, there is a default fair_day show whenever getWeatherIcon returns undefined