How many times before 1880 was it as hot as now?
During the last 10,000 years it's been as warm as today - or warmer - during:
* The Medieval Warm Period.
* The Roman Warm period.
* The Minoan Warm Period.
* And two long periods known as the Holocene Climate Optimums.
That takes us back to the last Ice Age. However: millions of years ago the world was on average much warmer - by 5 degrees C or so.