  The long temperature series at Svalbard (Longyearbyen) show large variations,
and a positive trend since its start in 1912. During this period solar activity
has increased, as indicated by shorter solar cycles. The temperature at
Svalbard is negatively correlated with the length of the solar cycle. The
strongest negative correlation is found with lags 10-12 years.
  The relations between the length of a solar cycle and the mean temperature in
the following cycle, is used to model Svalbard annual mean temperature, and
seasonal temperature variations. Residuals from the annual and winter models
show no autocorrelations on the 5 per cent level, which indicates that no
additional parameters are needed to explain the temperature variations with 95
per cent significance. These models show that 60 per cent of the annual and
winter temperature variations are explained by solar activity. For the spring,
summer and fall temperatures autocorrelations in the residuals exists, and
additional variables may contribute to the variations.
  These models can be applied as forecasting models. We predict an annual mean
temperature decrease for Svalbard of 3.5\pm2 oC from solar cycle 23 to solar
cycle 24 (2009-20) and a decrease in the winter temperature of \approx6 oC.
