blue_sky_over_the_lake_constance

Simplified, climate is the average of thermodynamic processes in the Earth's atmosphere (weather) over a longer period of time (at least 30 years according to the World Meteorological Organization), as determined by meteorological methods.

Consequently, the climate cannot be changed or influenced in the short term, but the weather possibly can.
It is therefore the totality of all weather events over a long period of time in a larger area (or globally) that is referred to as climate. On our planet Earth, which is about 4.6 billion years old, ice ages alternated with warm periods. For example, in the early Middle Ages we tended to have a small warm period, and in the late Middle Ages up to the 19th century we had a small ice age. In terms of Earth history, we are now living in an ice age [Source].

In any case, it is interesting and worth noting that very large climatic changes took place on Earth in the last 2000 years before the beginning of industrialisation - i.e. completely without human intervention - with an almost constant carbon dioxide content of around 280 ppm [source].

Even before 1900 there were massive floods and extreme temperature fluctuations.
For example, there is evidence of numerous severe floods in the Ahr and the Ahr valley in the Rhenish Slate Mountains over the last 600 years, as described here:
https://de.wikipedia.org/wiki/Liste_der_Hochwasserereignisse_an_der_Ahr (The original link to a page from the district of Ahrweiler has been deleted by the district).

Today, however, this fact is usually completely ignored by simply ignoring the pre-industrial period. 
With the term weather, on the other hand, we describe the current or, in the weather forecast, the probable coming thermodynamic state of the troposphere in a certain area or region.