An analysis of regional climate change in France between 1956 and 1997.

Daily climatological data (temperature, precipitation, sunshine duration) c overing the period from 1956 to 1997 for 68 locations in France has been an alysed. Seasonnal and monthly climate change is characterized by increases in minimum temperatures of about 1.6 degreesC in summer (0.9 to 2.2 degrees C; maximum in August) and 1.2 degreesC (0.6 to 2.3 degreesC) for the year, a less frequent increase in maximum temperatures (with the exception in sum mer; mean value = 1.8 degreesC), a frequent increase in the number of "warm " days (T-moy >5 degreesC) in automn and winter (14 to 31 days; mean = 19 d ays), a more modest decrease of frost days (T-min <0 <degrees>C), little tr end in the precipitation totals (decrease in August precipitation in the no rtheastern France) but a higher frequency of change in rainless days (decre ase in spring and automn). The sunshine duration decreases in June and incr eases in August and November and seasonnal trends mainly concerned southern France. Sampling bias and anthropic factors are discussed as possible caus es of the observed trends.