For historic output from nearby solar systems,
pvoutput.org has a map that you can locate installs near a particular area, and if you like can match details like size or orientation to best approximate your own - daily, hourly, 5-minute data is available if the contributor logged the granularity. Going back more than a month, you do have to log in to see the historic data - I think a free account would suffice, but not 100% sure, since I use a $10/yr paid account to upload my own data.
Alternatively, you can search the Enphase map of public systems
Enphase US Map
and view historic daily and hourly generation data as well. All are Enphase micro-inverter systems though.
For historic solar radiation data, you can search Personal Weather Stations (PWS) in
wunderground.com that upload near you, and find the rare one that has a solar sensor, and it will give you historic data from past days. I see in the daily view the irradiation graph over the day, but not sure if they summarize the total daily irradiation under the curve or not for you.