Historical climate
From Glossary of Meteorology
historical climate
The climate of the historical period, which may be taken as the past 7000 years; generally distinguished from the period of time during which regular daily observations from meteorological instruments are available, which begins generally in the seventeenth to eighteenth centuries A.D.
Thus, historical climate is the climate of a period of history for which no instrumental observations exist, but its main characteristics may be reconstructed from written descriptions.