SQLite: Get monthly, weekly or daily average of all entries - sql

Question

I have a SQLite database of records in this format:
date location temperature
1568463916 room 1 20.0
1568463916 room 2 25.0
1568463916 room 3 30.0
...
1568460316 room 1 15.5
1568460316 room 2 20.5
1568460316 room 3 21.3
Every hour three new records get inserted, one for every room.
For a monthly average this output is desired:
month avg_temperature location
01 21.333 room 1
01 24.5 room 2
01 19.0 room 3
...
12 20.4 room 1
12 31.31 room 2
12 13.37 room 3
The same query might be reused to get weekly averages (day 00-07) and daily averages (hour 00-23).
To get a monthly average, I'm assuming I will select:
All records with date between now and now - 1 year
Month of every record with strftime(date, "unixepoch") as month
For every location, then for every month get avg(temperature)
The result is rooms*12 rows of average temperature of each room for each month
When I'm using the GROUP BY statement however, I'm only getting the last row of every month. What's the correct way to construct this kind of query?
This is the query I've tried:
SELECT strftime("%m", date, "unixepoch") month,
avg(temperature) avg_temperature,
location
FROM table
WHERE date > date("now", "unixepoch", "-1 year")
AND date < date("now", "unixepoch")
GROUP BY location, month
ORDER BY month

Answer 1

This should do what you want:
select date(datetime(date, 'unixepoch'), 'start of month') as month,
location,
avg(temperature)
from t
group by date(datetime(date, 'unixepoch'), 'start of month') as month,
location
order by month, location;