The delta D time series for seven trees from six locations in North Am
erica were analyzed and compared with the regional temperature and pre
cipitation records. Correlations between the delta D and temperature a
re found to be particularly good for low-frequency variations or long-
term trends. Trees from locations with simple climate regimes and Aat
topography are potentially good temperature recorders. The moisture-de
pendent effect on the delta D values of tree cellulose is only evident
for the delta D record of a valley oak collected from an arid valley
near Los Angeles, California, USA. In such an arid environment, the co
rrelation between delta D and temperature may be poor due to limited n
umber of rainy days during a year and the strong effect of the amount
of precipitation on the delta D values of trees.