This is the 88th most frequent Estonian word.
nädalal
"Nädalal" means "on the week" in English.
In this sentence, "nädalal" is in the adessive case, indicating 'during this week', to refer to the ongoing period.
Sel nädalal on ilm jahedam kui eelmisel nädalal.
This week, the weather is cooler than the previous week.
Here, "nädalal" is also in the adessive case, used to specify the time when an action took place.
Ma külastasin möödunud nädalal vanaema.
I visited my grandmother last week.
In this context, "nädalal" is in the adessive case, referring to the upcoming time when an event will occur.