Abstract
Phenology season onset in the Czech Republic within the period 1991 - 2010. Phenological seasons are very different from astronomical or meteorological seasons.
In phenology they are determinated by typical phenophases which are connected with weather. It is divided into four main seasons, spring, summer, autumn and winter with three adjacent periods.
We have chosen typical species, which defined particular phenology season, data were exported from CHMI phenology database Oracle Phenodata. Maps of phenology season were created by Clidata-GIS with horizontal resolution of 500 meters with reference to altitude (method of local linear regression between the measured or calculated value and the digital relief model).
The part of results of phenology seasons onset: pre-early spring (1st March - 26th March) , early spring (16th April - 7th May), late spring (3rd May - 26th May), early summer (29th May - 30th June), late summer (29th July - 30th August), early autumn (7th September - 3rd October), end of autumn (14th October - 4th November).